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Purveyors of Electronic, Musical and Vintage goods from then, now and in between. 
Since 1982.

STEREO REPAIR / AUDIO REPAIR
DIY / QUESTION & ANSWER HELP
Stereo Equipment / Gear Issue Troubleshooting Q&A


Stereo / Audio technical issues Q & A.
These are some of the more common issues we get emails and calls about. Many, if not most of these issues can be solved by the user, for little or no money and using a 'process of elimination'. This is not meant to substitute as instructions, advice, nor in any way, to be training in electronics repair / restoration. When in doubt, don't do it yourself and consult a professional.
NEW INFORMATION ADDED or MODIFIED 9/25/2024

 

 

-WARNING: PLEASE USE CAUTION WITH ANY ELECTRICAL DEVICE. ANY REPAIR AND / OR

-RESTORATION SHOULD BE UNDERTAKEN ONLY BY A QUALIFIED TECHNICIAN. THE TEXT'S BELOW

ARE NOT INSTRUCTIONS FOR DOING YOUR OWN REPAIR AND ARE NOT COMPREHENSIVE IN SCOPE.




Due to limited resources we are only able to do restorations / repairs on OUR OWN inventory and unable to take OUTSIDE / CUSTOMER repairs.
If you need work done to your gear,
>TRY         SOME         OF         THESE         RESOURCES<


 

 


ATTENTION: We recommend you DO NOT DISASSEMBLE or ATTEMPT TO REPAIR OR REPLACE ANY PARTS ON ANY ELECTRONIC / ELECTRICAL DEVICE without proper, technical training and repairs / modifications should always be left to qualified technicians.

"WARNING: PLEASE USE CAUTION WITH ANY ELECTRICAL DEVICE. ANY REPAIR AND / OR RESTORATION SHOULD BE UNDERTAKEN ONLY BY A QUALIFIED TECHNICIAN. DO NOT OPEN OR ATTEMPT TO REPAIR ANY ELECTRONIC DEVICE WITHOUT PROPER INSTRUCTION, EXPERIENCE, BACKGROUND, TRAINING OR KNOWLEDGE, OR TAKING PROPER SAFETY PRECAUTIONS. THERE ARE NO 'USER SERVICEABLE' PARTS, SYSTEMS OR CIRCUITS INSIDE. POTENTIALLY HARMFUL, INJURIOUS AND / OR LETHAL ELECTRIC VOLTAGE AND CURRENT INSIDE AND IT WILL HURT THE ENTIRE TIME IT'S TRYING TO KILL YOU."

The following information is for 'entertainment value' ONLY and not intended as 'how to' / DIY instructions, and by NO MEANS is it instruction on how to repair, nor intended as incentive nor encouragement to tackle any electronic repairs yourself!
 

 


                                                                        


These are some of the more common issues we get emails and calls about.
Most of these issues can be solved by the user, for little or no money and using a logical 'process of elimination'.
This is not meant to substitute as instructions, advice, nor in any way, training for anyone not already correctly and competently qualified in electronics repair / restoration for issues / repairs that require proper training or a qualified electronics technician.

 When in doubt, don't do it yourself and consult a professional.


 

Stereo Receiver / Integrated Amplifier / Pre-Amplifier / Audio-System Q&A:

Issue: My Stereo Receiver / amplifier / system will not power up or 'turn-on'...

A: Assuming you've done the obvious of making sure you have a 'good' (hot) AC outlet to connect to, and you've paid your utility bill, there's not much that falls into the realm of 'user serviceable' solutions. Of course there could be an 'externally located' AC / Mains fuse on the rear of the unit. Easy enough to check (make sure that the unit is disconnected from AC power prior to removing the fuse cap). More likely there are 'internally located' AC / Mains fuses, along with others. That becomes a bit more involved to locate and change, and may not fall within the 'skill set' of many users.  Beyond 'fuses' there's not much you can do, except find a service facility that would be willing to take a look.  The potential 'good news' with a 'totally dead unit' issue (barring catastrophic transformer issues) is that the problem is commonly easy to rectify (relatively speaking).
 

Issue: The sound on my Stereo Receiver / amplifier cuts out at any volume and on any source...

A: The most common cause of sound intermittently cutting out on one or both sides of a receiver / amplifier is a dirty 'Tape Monitor' switch(es) followed next by a dirty / corroded 'Input Selector' switch.
To troubleshoot, individually manipulate each ‘Tape Monitor’ switch rapidly, numerous times, while monitoring the sound until you find the switch that affects / improves the performance. If that affects it, then the switch needs to be cleaned or ultimately replaced if cleaning does not fix it sufficiently. If the ‘tape monitor’ switches have no effect, then examine the ‘input / source’ selector with the same procedures. If still no effect, then start touching / manipulating the rotary controls such as Volume, Balance / Tone etc, Loudness, Audio-Mute, Stereo / Mono switch etc. Also check the ‘source’ connector cables (RCA) for connection integrity / quality.
If the sound tends to cut out only at lower volumes, then it is likely corroded contacts in the ‘Speaker Selector’ switches.
This can usually be deduced by carefully manipulating the speaker selector(s) while listening at a lower volume. If the sound tries to come back while pushing / turning / flipping the speaker switches, then that is the likely culprit. Cleaning a 'speaker selector' switch with a liquid agent might address it, but it usually requires a more aggressive method such as disassembly of the switch to allow ‘burnishing’ of the internal contacts. They have likely been ‘arcing’ due to the higher current that passes through the speaker selector switches and liquid cleaners will not fix that. If the arcing has severely ‘pitted’ the contacts, the switch may need to be replaced.

 

Issue: Volume, Balance, Tone controls have static when turned or moved on my Stereo System...

A; This is one of the most common issues with any unit over about 5 years, old and certainly most any unit that would be considered ‘vintage’. The problem is usually solved by a thorough cleaning (by someone qualified) with an appropriate cleaning agent such as GC Electronics-De-Ox-Id, Caig DeoxIT D5 or G5, De-Oxit, Chemtronics, MG Chemicals 'Electrosolve' Contact Cleaner, TechSpray contact cleaners / tuner cleaner spray, or similar (beware of the ‘super cold’ cleaners on some of the older internal plastic / nylon components, as they can be ‘shattered’. Also, some cleaners / solvents can 'melt' plastic parts or react with plastic internal and cosmetic parts).  All the controls and (and switches as possible) should be cleaned at the same time while a tech is in there. If after repeated cleaning the problem persists or it only works for a limited time after a proper cleaning, then ultimately the control / switch may need to be replaced. PS. I have folks tell me all the time that they “removed the knobs and squirted some of that cleaner back in there and it didn’t help at all”. That would be akin to opening your fuel tank door on your car, pointing the nozzle at the gas cap and pulling the trigger. Unless you remove the cap and actually ‘insert’ the nozzle, nothing gets in. Unless you go into a control potentiometer (sometimes erroneously referred to as a 'rheostat', which is a different kind of 'attenuation' control, usually used for larger amounts of current, than a 'variable resistor / potentiometer')or switch from ‘typically’ rear-located access ports   and flood the control internally, no cleaner gets to where it should.

A note about sourcing replacement switches, pots / potentiometers / controls for vintage stereo / audio gear.
 Most parts are 'fairly' to VERY specific not only to a particular brand, but specific down to a ‘handful’ of models and sometimes unique to ONLY ONE MODEL. There are many parameters to finding a replacement part, especially potentiometers. Besides the resistive value, there’s ‘taper’ as in ‘Audio taper’ or ‘linear taper’,  some potentiometers such as ‘balance’ pots have a ‘center detent’ / notch,  some are double stacked,  some are quad stacked,  the legs / terminals usually need to be of the same dimensions (although you may be able to 'scab' on leads),  the metal ‘body’ may need to be of a particular dimension (some are large and some are small(er),  the mounting thread diameter and length are likely critical,  the shaft length, shape and design are almost ALWAYS critical,  there may be an unusual current value assigned to it,  it may have multiple ‘jobs’ and have other terminals on top etc.  
Bottom line is, you probably ‘ain’t gonna go to Radio Shack and pick one up’.  In fact probably the only place you’re going to find a suitable replacement is from a salvage / donor unit of the same model, or at least a model that uses the SAME parts (unless you don’t care about the originality of the unit, exact performance, exact look etc, but then hey, you could probably make something out of a bit of old carpet lint, a little spit and some duct tape’ work, right?....).  Potential sources for parts you could ‘make fit’ might be:  www.oaktreevintage.com/Stereo_Parts_Salvage_Units.htm  ,  www.dalbani.com ,  www.electronix.com ,  www.mcminone.com ,   www.newark.com  ,   www.studiosoundelectronics.comwww.suburban-elect.comwww.tedss.com 
If you have a parts source to suggest, or 'are' a source for potential parts, let us know and we'll consider adding the info.

 

 

Issue: When I ‘touch’ the: ‘Volume’, ‘Balance’, ‘Bass’, ‘Treble’, (etc) controls the sound cuts out. I don’t even have to turn them. Actually they sound fine when I turn them, only when I ‘push’ / ‘pull’ / ‘touch’ / 'jiggle' them does the sound cut out...

A: That is a less common issue and if we rule out ‘dirt’ or corrosion, then the next likely suspect would be bad solder joints or ‘cold’ solder joints. Re-flowing the solder joints by someone qualified usually is the fix.

 

 

Issue: The sound on my stereo cuts out, but only at ‘higher’ volumes...

A: If everything is generally OK at lower volumes (say below 8:30AM or 9:00AM, if you imagine a 'clock face' on the stereo units' volume control), and you’ve ruled out the above issues, then consider some of the following possibilities as potential causes;

-A single strand of speaker wire just ‘touching’ a neighboring strand can allow an amplifier to function, but likely at an elevated temperature, which will reduce it’s ability to perform at elevated volumes. Since ‘higher’ volumes means higher temperatures, any unnecessary increase reduces the amount of ‘leeway’ an amp has to do it’s job. The amplifier will run hotter than it typically should.
     Solution; Inspect and rectify speaker wire connections.

- Too many speakers connected to the output of an amplifier resulting in too low of an impedance load on the outputs, or speakers with an impedance lower than the amplifier is designed to handle, or a combination of the two. The amplifier again, will run hotter than it typically should.
     Solution; Reduce the load on the amplifier, either by choosing speakers of a ‘higher’ impedance rating, eliminating speakers, re-wiring to a 'series' or 'series-parallel' combination or a combination of solutions.  You may need to consult ‘Ohms Law’ to determine correct combination.

- Output transistors that are not cooling sufficiently, usually due to a build up of dust / grime on the output transistors, heat sinks and other cooling apparatus. I have seen many units with layers of ‘build-up’ on the internals, especially from units used in or around kitchens, industrial areas, shops, garages etc. This grime acts as an insulating blanket, trapping heat and reducing free air flow to parts. Heat is the primary ‘killer’ of electronics, and anything you can do to reduce it will likely lengthen the lifespan of a unit and reduce a performance robbing issue.
     Solution; Have the unit properly cleaned internally by someone qualified. Hopefully irreversible damage has not been done.

- Weak output transistors, or transistors that are ‘on their way out’, or have a bad solder joint somewhere in the signal / power output path.
     Solution; This problem would need to be addressed by a qualified electronics technician.

- Simply a speaker load that is too large for the volume you are trying to achieve (similar issue addressed above).
     Solution; Either use less speakers, or higher impedance speakers, or a combination of the two, or get a larger, more ‘sufficient for the task’ amplifier / receiver

- 'Compromised' / 'Cold' / bad solder joint / connection somewhere in the signal chain that only gets connection when there is enough current to 'arc' across the gap in the joint / connection.
     Solution; Find the errant joint / connection and re-flow the solder joint (and inspect and re-flow any other 'questionable looking' ones) or improve / fix the connection. (This can be easy and quick, frustrating and time consuming or anything in between and sometimes seemingly impossible to find or locate)

There can be a myriad of other possible reasons for the ‘high volume / cutting out’ issue, but the above are the most common we’ve seen.

 

Issue: I was playing 'fairly loud' (70% OR MORE, of the way up the volume control) with 4 speakers (or one pair of 4 Ohm speakers) and my receiver / amplifier 'smoked' / blew up!...

A: Well, 'the horse is out of the barn' now, but YOU CAN'T DO THAT!!! 75% of the way up on a volume control (about 3:00 O'Clock) is WAY TOO MUCH. Generally, the only thing past about 1:00 and certainly 1:30 is 'clipping' and extra heat. 
PLUS you were playing the maximum load at 4 Ohms (or maybe less). 98% of amplifiers (receivers) can't do that, at least not for very long.
To use an analogy, you were driving with your tach past 'red line'.....and you were pulling a trailer (that's at the top weight of what your vehicle is rated for)....and you were trying to maintain 75 MPH....and you were going 'up hill'.   You generally CAN'T DO THAT, at least not for very long.  Period!
(well, actually, I can as I have a 'Duramax diesel' (except for the "red line" part)).
     Solution; Again, the 'horse is already out of the barn, but in the future, reduce the load on the amplifier, either by choosing speakers of a ‘higher’ impedance rating, eliminating speakers, re-wiring to a 'series' or 'series-parallel' combination, purchase additional amplifiers suitable to your needs or a combination of solutions.  You may need to consult ‘Ohms Law’ to determine correct combination.

 

Issue: The sound on my stereo cuts out when the wires in the back are jiggled or moved.

     A: Then don’t move the wires!  Just kidding.  You either likely have bad RCA cables (prevalent on cheap cables / connectors the system is most likely connected with) or the solder joints on the jacks / connectors are bad or ‘cold'. Methodically moving the cables around will often find which cable / connector is the culprit.  Replacing the cables (preferably by somewhat higher quality versions this time) or re-flowing the solder joints by someone qualified usually is the correct fix. Occasionally the RCA jacks or plugs can become oxidized enough to cause this. A ‘quick fix’ is to repeatedly ‘rotate’ the plug to scrape off the oxidation and expose clean metal can 'fix' the issue.

 



Issue: My Receiver / Amplifier only plays very low sound and the sound is very distorted. I’ve tried the above / previously mentioned solutions to no avail.

     A: Low and distorted sound on one or both channels of a stereo receiver / amplifier that never improves or recovers by any of the above means, likely means that your receiver / amplifier has bad outputs (output transistors) and you are simply hearing the sound from the 'pre-drivers' passing through.
 
        These types of situations require a qualified electronics technician and correct replacement parts.

 

 

Issue: I get no sound at all from amp / receiver, but it ‘powers on’ (I’ve gone through the above check list already).

     A: There is a myriad of possible problems / solutions. First would be ‘operator error’ issues such as; 

     1) Are the speaker selectors set correctly?, 

     2) Are the speakers ‘known to be working’ and connected correctly? 

     3) Do you have a ‘good’ signal source, ie; CD player (usually most reliable), next would be a good FM signal? 

     4) Is the balance of the switches / controls set correctly (a common one is that a ‘tape monitor’ switch is left engaged)?

Next would be to check ‘non-operator’ error issues such as:

     1) Most 'later model' (from mid 1970's on) stereo receivers / amplifiers have ‘speaker turn-on’ relays to protect against DC surge to your speakers from an amplifier 'powering up'. If yours has that, then you likely normally hear a faint ‘click’ a few seconds after powering the unit on. If you no longer hear that, then that tells you there is a technical problem either with the amp, the speakers or the connection of the speakers (no the relay is not usually the issue, but if all else ‘checks out’ then bad / corroded / arcing relay contacts can be a cause)

     2) Next, some of the higher quality / better models may have a ‘pre-amp’ OUT / ‘main / power amp’ IN loop. On a few models these ‘default’ to a ‘working state’ even if nothing is connected, but most will require ‘shorting plugs’ / ‘shorting jumpers’ to be connected. These are ‘U’ shaped, thick, solid wires and if you don’t have the originals, they may be difficult to source. A workable substitution is a pair of RCA cables. Some units used a slide switch to make this connection, and it could have corrosion blocking the signal (would have to be heavy corrosion and not likely be effecting both channels). 

     3) Next would be to check any fuses. Some receivers / amplifiers have speaker protection fuses that may be located on the back of the unit that the ‘user’ can inspect / replace. Most that have fuses, however, have them located inside the unit. Those should likely only be inspected by someone properly qualified. 

     Beyond the above mentioned issues, most anything else is likely going to require a qualified technician to deduce and is beyond the scope of what we can advise on.
 

 


Issue: My stereo receiver / amp ‘sizzles’ or makes a sound like bacon frying, and / or the dial lights dim periodically when on.

     A: We see this periodically, and more typically on lower end stereo units. It is commonly a sign of the 'Power switch' arc'-ing. This is common on receivers such as the Pioneer SX-450, SX-550, and some Kenwood stereo receiver such as the Kenwood KR-5030, KR-6030 & KR-6050. They use a type of power switch that is conducive to this issue after 25+ years. Remedy, replace the power switch or sometimes a ‘second’ set of terminals may be available on the switch that are not being currently used. We have not found a source for this switch other than 'take-outs' from salvage units and we're almost always sold out of them (or more likely have used them for ourselves) (revised 2018).

An alternative email we received; I have a older pioneer stereo reciver sx- 9800 (SIC?) with 25watt. will de-oxit spray [contact spray cleaner] get (SIC) sound louder? It flickers when I put on-off switch to power. . how hard is it to replace switch?

     A: The 'flicker' symptom you are describing is the power switch 'arcing' (which you already eluded to). It's probably also accompanied with a 'sizzle / bacon frying' sound. That is not easily repairable except to replace with another switch (likely from a donor unit of the same model). Alternatively you could 'shunt' the wires internally to 'ON' and use an external 'power strip' to power up the unit. It might be possible to dissect the switch and try and re-burnish the contacts, but that's usually VERY DIFFICULT at best, if possible at all. Another possible alternative is if your unit utilizes a version of the switch that has a 'double set' of contacts on the top, that are not being used, you can invert the switch and you'll have a fresh set of contacts, but only occasionally do we see this version.  (DON'T DO ANYTHING UNLESS QUALIFIED TO BE INSIDE AN ELECTRICAL UNIT).
Contact cleaner will NOT address 'power switch arc'-ing' ' issues. It will usually take care of cleaning the contacts and surfaces of 'lower current' switches and controls such as pots and selector switches.
 


Issue: My Realistic STA-2000 / STA-2000D, STA-2001 / STA-2100D, STA-2300, STA-2500, stereo receiver, and possibly others of the 'larger Realistic Receivers', will not turn off.  The power switch is 'stuck' in the "ON" position..

     A: We have seen this on many of the larger / 'Big Boy' Realistic STA receivers. Whatever switch they sourced back then has not fared well 40 years later. We don't have a replacement for it yet. Most folks 'work around' it by using alternative methods to 'power it on / off' such as a 'switched outlet strip' or make a specific switched outlet for it. Once we had one that someone had 'drilled' into the wooden side panel, and installed a 'hardware store' switch.  I didn't like that as it now had a hole in the original wooden side panel.  Other then their 'power switch', large, Realistic receivers are generally FABULOUS performers all around. I have no other complaints about them.
 

Issue: The 'tone controls', ie; Bass, Mid and / or Treble do not make any difference when turned...

     A; There's usually only one explanation I can think of for that an that would be that the unit features a 'Tone Defeat' / 'Tone On / Off' / 'CD Direct' or similar function that bypasses the tone control circuit. This feature is usually only found on upper-mid to upper end models. When in the 'Tone Off' or 'Tone Defeat' position, the tone controls will have no effect on the sound.

 

Issue: I can hear the radio / CD, etc. 'bleeding' over onto other inputs such as AUX, TAPE, CD etc.

     A: It is fairly normal to hear one source bleed over into another if the 'currently monitored' source is silent or near silent, and there is a strong enough signal / program material on another source currently. You could call this 'cross-talk'.  CD's playing on a player, but not being monitored are the 'worst offender' for this issue. CD's have such a high potential dynamic range that it is difficult to filter out all of their sound. One thing that will help is to keep unused inputs capped off with 'shorting' plugs. These are RCA plugs that have their hot and gnd connected. Generally when a source is connected to an input that takes care of that (at least to a sufficient degree). Secondly, the 'bleed' signal is usually low enough, and the 'currently monitored' source is strong enough to override.
Just FYI. Some units actually came new with 'shorting plugs' inserted into most of the RCA inputs. Most units with 'Dual Phono' inputs will have at least one set of shorting plugs, as there is usually a 'phono pre-amp' located behind them that will 'readily amplify' even the smallest of noise that might be floating around. Yamaha is one brand that comes to mind that typically included  shorting plugs occupying most of RCA jacks on their higher end pre-amps 'out of the package'.
     Another possible reason for this is that you have inadvertently connected the 'offending source unit' into 'Record Out' on one of the tape monitors, instead of 'Play(back) In'. Simply reconnect it to 'Play In' or 'Playback In' (or similar label) and that should solve the issue.


 

Issue: At higher volumes, my sound, especially the bass, seems to distort, especially the bass and / or I get a 'sharp pop or snap' from my speakers...

     A: All receivers / amplifiers have a limit to the power / volume they can safely produce. Most are going to 'red line' at approx 1:00 or 1:30 PM (looking at a 'rotary' volume control as a clock face) on the volume knob. Generally much past that does not result in any more power or actual volume, but simply an increase in distortion or amplifier clipping. I say "generally", as while there are some exceptions to this rule, they are VERY rare (Barney Oliver amplifiers and a Kenwood KA-6105 are the only two that immediately come to mind). Don't increase the volume past 1:00 or 1:30 (again, think of the 'rotary' volume control as a 'clock face', with 'straight up' being 12:00 Noon or 50% of it's rotation. If your unit has a 'linear-fader' style volume, then think of it as a percentage of it's total 'throw', so 55-60% would generally be max). Now there are many variables that affect those limits such as amplifier design, build-quality, speaker loads, designs and impedances, but again, the above 'rules' are generally applicable.
Also, Reduce 'Bass' and any of the lower bands of an EQ, either built-in or external EQ, proportionally as volume is increased past 10:00 AM.
Discontinue utilizing 'Loudness' control past approx 10:00 AM on volume control.
I've heard many people ask, "well why does my volume control go to 'ten' or all the way if I can't turn it all the way up? Well, it just does. Your accelerator goes all the way to the floor, your tachometer goes to 8 or 10k and your speed-o-meter probably goes to 120 or 130 MPH, but you don't generally want to go driving around that way for a lot of reasons. The same basic principle applies to the volume control and EQ on a receiver / amplifier.
 

Issue: I don't get any sound from the 'B' speaker output on my Kenwood KR receiver...

     A: While there could be other reasons, the most common reason for an issue with the 'B' speaker output on a Kenwood KR receiver, is that you only have speakers connected to the 'B' outputs. I don't know why, but for some reason (maybe someone will enlighten me), most Kenwood KR receivers will not produce output from the 'B' speaker outputs, unless you first have a load (speakers) connected to the 'A' speaker output. Also, be pay attention to the speaker output labeling convention when connecting speakers to Kenwood receivers and amplifiers. While most manufacturers will arrange speakers 'in pairs' going horizontally (across), Kenwood's tend to arrange their pairs 'vertically', so if you're accustomed to connecting speakers 'horizontally' by habit (probably only a habit by folks like me, who have to do things like that a lot), pay attention, or you'll connect both speakers to either the A&B 'Left' outputs or 'Right' outputs. Just FYI.

 

STEREO SPEAKER ISSUES / PROBLEMS:

Issue: One of my speakers’ sound cuts out periodically on one side.
I have already gone through the above / previous check list.

     A: First check some of the above symptoms that may involve the receiver / amplifier. If related issues already listed above can be eliminated, then check for fraying speaker wire, connection integrity of your sources and speakers, inspect speaker input panel for broken / loose connectors. If that is all in order, then swap the speakers (left and right) and see if the issue ‘follows’ the speaker, or stays on the same side (to isolate the issue to the amp or speaker). If it follows the speaker, then you may need to further check the connection at the speaker or internally inspect the speaker.

 


Issue: One of my woofers sound cuts out periodically on one side. (I have already gone through the above / previous check list.)

     A: This issue may be from a speakers ‘spider’ wires that are going bad from too much flexion over the years. To deduce the problem, you can GENTLY manipulate the spider wires while sending a signal to the woofer. Sometimes you can ‘re-solder’ a bad section or shorten it a BIT if the bad part is near the speaker connection terminals, but replacement of the flexible spider wire is the best solution. If it’s broken / intermittent in one spot, it’s probably getting ready to ‘get tired’ in other spots. This may or may not be within a users ‘skill set’ (meaning it ain’t necessarily easy to do). If you don’t know what the ‘spider wires’ are in the first place, you probably need to send the woofer out to a professional for repair or if the original driver (speaker) cannot be repaired or sourced then a suitable replacement may be in order.
(revised 2018)



Issue: One of my woofers is 'frozen' / doesn't move even if I attempt to manipulate it by hand.

     A: While this can be due to a few reasons, the most common is that the voice coil was 'heated' beyond it's capacity and 'deformed' / swelled to the point that it 'filled' the VC gap, thus restricting movement. This is usually caused either by simply too much power / brute force from the power amplifier / power source that was beyond what the speaker was designed to handle. In reality, this does not happen very often relative to other speaker / driver issues. Another reason, that actually is more common, is from an amplifier / amp / receiver's amp that is now sending out DC or is DC'ing. This is caused typically by 'shorted' outputs that are simply passing DC Voltage, at a fairly high level, ie, 40-70 or more volts. This would also mean that any 'DC Protection' that is normally built into most quality amps (since the mid 70's) did not do it's job.
This usually occurs at 'turn-on'. You will simply hear or 'sense' a low frequency 'thunk' or see the woofer move out or in....once. After a very short time, the voice coil simply turns into a 'space heater', bubbles up the lacquer on the copper coil, shorts further and expands / burns up in the gap, then either blow a fuse in the amplifier, burn-thru at the voice coil, thus terminating the connection, burn thru at the spider wire, or if it continues, actually catch on fire. This will require a 're-cone' as well as determining why the amp is 'DC'ing'. DO NOT USE THAT AMPLIFIER UNTIL IT HAS BEEN REBUILT / OVERHAULED. In that state, the amp / receiver WILL continue to destroy woofers / low frequency drivers
(damage from DC is usually limited to the lowest frequency driver, as the drivers that handle frequencies above the woofers are typically protected by capacitors in the crossover network which will block DC from the balance of the drivers such as mids and tweeters).
      There is another reason we see for a 'locked-up' / 'frozen' woofer / driver voice coil. 'Magnet Shift'. On about 50% of the 'Polk Audio' speakers that come thru the shop, we will expect about 50% (at least) of their woofers to be 'locked-up'. This is due to 'magnet shift'. They are very susceptible to shock / vibration. Even going down stairs on a 2-Wheel dolly, WITH pneumatic wheels can be enough of a jolt to cause it. I've had 'vintage' Polk Audio woofers 'shift' while holding them in the palm of my hand.
    Another time I saw it was in a Klipsch Subwoofer that was dropped off the edge of a stage, which caused the magnet locating pins to sheer, it's epoxy to give way and then to lock up the voice coil. Not much you can do in that situation, except higher professional roadies....




Issue: The higher frequency parts of my sound on one of my speakers cuts out periodically or my tweeters do not seem to be working (Mids and tweeters cutting out intermittently).

     A: Many speakers have ‘Attenuators’ to tailor the ‘top-end’ frequencies. These are a common source of issue on speakers over 20 years old. Manipulate attenuators rapidly back and forth on each speaker cabinet (one at a time), while monitoring a signal (preferably ‘white noise’) and see if the 'quiet' drivers start working (even if intermittently). The attenuator contacts oxidize / arc and will need to be cleaned**. Once cleaned and / or ‘re-sprung’ (sometimes a painstaking process) they should perform correctly.
If that was not the source of the issue, check any speaker fuses or reset breakers. If still no resolve, then you may need to remove the drivers (midranges / tweeters etc, and inspect / test independently and individually).

** "cleaning" 'higher-current' contacts such as "attenuators", "Power switches", "Speaker switches" etc. typically are going to require more than just 'spraying with some contact cleaner'. Their 'intermittent' issue is not likely due to the same causes that afflict 'potentiometers' such as dust, smoke, tarnish etc, but a carbon build-up due to the 'arching' action of higher, 'speaker level' currents. That will usually require more 'invasive and physical' intervention such as sandpaper, emery board, burnishing strips etc. Think 800-1500 or higher grit. Each potential contact combination will need to be addressed. Care should be taken not to 'spring' any of the contact fingers.
Having
said all of that, it’s not typically the coil windings of the 'track' that are the issue. It’s usually the brass or silver plated track in the bottom of the cup / housing that the center / "wiper" terminal rides on (at least in most). That will need to be physically burnished. We use a fiberglass pen. Most L-pads / rheostats etc were not meant to be disassembled, so there’s that additional hurdle as well. Also, doing this may remove an original, protective plating meant originally to prevent the effects of arching, but as 'new / replacements' aren't often available, it falls under the heading, "what have you got to loose". Ultimately, speaker "attenuators" can be bypassed or removed from the circuit if need be (which in my opinion, is almost always the BEST option by far).
     A note on how to ‘quick test’ speakers / drivers (driver means; woofers, midranges, tweeters, super tweeters etc.). Most folks will play a CD or similar source to test their speakers. This is not a very accurate, or even useful way to deduce speaker condition due to a particular ‘cut’ or  music selection may not necessarily have the frequencies you need, strong enough to excite particular drivers at the time you are trying to test (hear) them. This is especially important on drivers such as ‘Super Tweeters’ or ‘Subwoofers’ (actually subwoofers are fairly ‘rare’ in REAL and traditional ‘2-channel’, home audio systems). Super Tweeters commonly do not excite until 12-15kHz and there’s typically not much going on up there in most music. ‘Subs’ do not typically become active until below 120Hz or hopefully lower and there’s sometimes nothing in a mix at those frequencies as well.
The best way to test speakers / drivers for basic function is to use an FM tuner, with the FM muting turned 'off'. Tune the FM radio / tuner to one of the extremes of the dial (lower / left end is better) to a point where you get nice, clean, steady ‘hiss’. That is essentially ‘white noise’ and a close proximity to ‘pink noise’ which is a close representation to all frequencies being played at once (there’s other parameters to ‘pink noise’, but unimportant for the above test. Also, keep in mind that your FM tuner likely has a steep filter at 15kHz as that's the FCC cutoff limit).
See what differences (if any) you have between the two speakers. Turn the attenuator knobs between their 3 positions and see if the drivers are intermittent, or the changes seem 'errant'. Each should reduce the tweeter volume or the midrange volume slightly. Likely what will happen is that as soon as you try and move a knob, drivers will cut out. This is a sign that the attenuator contacts need to be cleaned  (likely meaning burnished, which is not typically an 'easy' task)  (and the contacts should be intermittent at this point).



    AR-3a Mid-High Attenuator being cleaned / restored.

Here's a request that came in recently:

Question: "CV-3000 replacement crossovers. Are there any available or optional versions available for use. I love my old Cerwin Vega speakers but the rheostats for the midrange speakers are giving me trouble. I have tried using the product detoxit but so far no success. Can you possibly help me out with this issue please. Thanks"

Our Response:
“Hi , Thanks for visiting oaktreevintage.com . That would be expected with ANY speaker designed with “L-Pads / Attenuators”. The vast majority of owners, simply leave them turned up all the way, which is the same as them NOT being in the circuit. If that is the case with you, and you don’t need them, I would just ‘jumper’ across them (fairly easy to figure out for most circuits with some web research). When we do ‘permanent installs’ in retail shops, bars, breweries, restaurants, etc. with ‘vintage’ speakers, we bypass all the attenuators (along with a few other modifications to the speakers for a commercial installation). They are a common failure point over time with almost 100% probability. Even if I did have them available, mine would need to be cleaned as well. If you’re ‘dead set’ on cleaning them, it’s not typically the coil windings of the 'track' that are the issue. It’s usually the brass or silver plated track in the bottom of the cup / housing that the center / "wiper" terminal rides on (at least in most). That will need to be physically burnished. We use a fiberglass pen. Most L-pads / rheostats etc were not meant to be disassembled, so there’s that additional hurdle as well. Hope all that helps. Good luck & Thanks again, Jerry at www.oaktreevintage.com  "

Another email:
    
“I have inherited some nice speakers (Sansui SP-2500X).  all I see is scratchy switches in each one.....they seem very hard to access. do you have any recommendations as to how to access the switches?...I am in Toronto…would love to get in there with some good contact cleaner! its a tough fit”

Our Response:   "Hi Bob,
Thanks for visiting oaktreevintage.com. So, attenuators are almost always going to be causing issues / intermittencies at this point. They need more than what any “Contact Cleaner” can do. You can try spraying the wafers / contacts with cleaner and then racking them back and forth a couple dozen times. Might fix the issue for a while, but typically temporary. The best attenuators are “NO” attenuators, ie; bypass them with jumpers. If, however, you really want to keep them intact, the only way we’ve really found to address them is to burnish the contacts (very carefully to avoid bending / distorting) with very fine wet/dry sand paper (in the 600-1200grit range). We actually have that, plus burnish sticks, plus fiberglass pens that we use (I don’t think the “X” version of the “2500’s” will allow the use of a fiberglass pen). Hope that all helps. Good luck and thanks again, Jerry at www.oaktreevintage.com"


Issue: I have 'Super Tweeters' on my speakers, but it doesn't seem like they're working.

     A: Some speakers have tweeters that are designed to reproduce frequencies in the uppermost range of human hearing (and beyond).  These are typically referred to as "Super Tweeters", and are usually relatively small. While most 'standard' Tweeters might be crossed over with a 'low end' cut-off of 6kHz, 8k, 10k or 12kHz, 'Super Tweeters' usually don't start to be excited until frequencies reach at least 12kHz, but more often 15kHz.  There are a number of possible reasons why someone might think their super tweeters are not working.  The first is, "there's not a lot going on in most music" in that frequency range, and even if there is, it might not be at a time you are listening, nor of sufficient amplitude (volume) or duration enough for you to make a quality judgment call as to their true condition.  Secondly, they probably are in 'close proximity' with other tweeters, and will likely be too 'overpowered' to hear to any practical degree.  Thirdly, and no offense, your ears may not be sensitive to frequencies in those upper registers anymore (or ever).
     So the most practical way we've found to test super tweeters is with 'white noise'.  White noise is a fairly representative mix of the 'human hearing range' at ALL times, and at somewhat equal amplitude (not as good as 'Pink Noise' for audio testing, but unless you have a 'Pink Noise' generator hanging around (and I'm going to guess you don't)), you probably do have a way to generate 'White Noise'.  If you have an FM tuner (analog type is best, but some digitals might also suffice), with a way to disengage the "FM Muting" (and most 'analog' types do), then simply turn off the FM Muting, so that you get 'hiss' in between stations (this is akin to 'Squelch' on a CB, if any of you are old enough to make that connection).   We are looking for the most 'pure / clean hiss', with no program material (the 'lower / left' end of the scale is the best place to find a section of 'pure hiss').  This is White Noise.  Now, balance your speakers either to the left or right.  Turn the 'Loudness' Off and the 'Bass' (and 'Midrange' if you have it) all the way counter-clock wise.  Turn the Treble control all the way 'up' (clockwise).  You shouldn't need the volume very high for this test, and don't turn it very high, as if you need to test for an extended period of time, you'll likely 'desensitize' your ears too much for any accuracy, and you risk damage to your hearing as we're going to have our ear VERY close to the individual drivers (call them speakers if you must).  At this point you may or may not hear anything.  You're not going to likely get a lot of 'volume' from the super tweeter for another reason, and that is that the FCC limits FM broadcasts to about 15kHz on the top end, so if your crossover is set at 15k, then the tweeter will just barely be getting much signal, but in the end it will be sufficient to determine of they function.  At this point you may not be hearing anything.  You could have a dirty attenuator (see previous section) which could be affecting the signal flow to the super tweeter.  Ruling out a dirty attenuator, you may need to dismount the super tweeter(s) and if their leads are long enough, pull them out from the cabinet, away from the other tweeters / drivers enough to determine if they're working.  Commonly, that will still not be sufficient enough isolation to make an accurate determination, and you will need to completely remove them from the cabinet.  At this point you could make / rig some extra wire to allow you to move the super tweeters completely away from the cabinet.  Here at our shop, we skip that step, and remove the super tweeter completely and test it independently.  To do this, we connect it directly to the output of our receiver / amplifier.   CAUTION: If you are going to do this test, you must be VERY careful, as terminal damage to the super tweeter can result if you aren't careful (yes you could connect the correct 'filter cap' in series with the tweeter to protect it, but if you can do that, you probably don't need to be reading this paragraph on "how to test a super tweeter").  We connect a 'control speaker' (can be any speaker, but the speaker you removed the super tweeter from is sufficient) to one side of the amplifier (make sure that the disconnected leads from the super tweeter are isolated from one another).  To the other side, we connect the 'super tweeter' to be tested using a length of speaker wire and / or 'alligator clip' / test leads.  We balance COMPLETELY the pre-amp over to the 'control speaker' prior to powering up the amp / receiver on.  We then do the above mention 'White Noise' procedure.  At this point you should hear fairly 'thin' white noise coming from the 'control' speaker.  Assuming that, now turn the volume down to a point where you can barely hear the hiss, then start slowly turning the balance control to the 'super tweeter'.  It's a good idea to also keep a hand on the volume control, to regulate that, insuring that it doesn't get 'too loud' as super tweeters are generally fairly fragile.  We only looking to detect even the slightest amount of hiss (again, "barely hearing" anything coming out could be due to the "FCC limits" or hearing issues on your part).  Now, at this point if you don't hear anything (and we are assuming your amp / receiver is working properly on both sides and your 'test jig' is correct) either the tweeter has an issue, or you can't hear it's range (common issue).  If 'lack of hearing range' is a possibility, the recruit some 'other ears' (preferably 'younger' or 'less stressed' from 'life's hazards') to give it a listen.  There are further possible tests, but the above should take care of 99%+ of situations.
     The above 'White Noise" method is also very handy for testing your speakers 'overall performance / health' and to determine correct 'phasing'.  Simply adjust the 'tone controls' to their 'defeated' position (if they're 'rotary', that would be the 'straight up Noon' position), and balance your speakers Left then Right.  Any appreciable difference in sound could indicate you have an issue with your speaker(s) that need to be investigated (if there is a difference, left to right, swap sides with the speakers / wires to rule out potential issues with anything 'upstream').  Your speakers should sound very similar to one another all the way from the low end / bass to the upper end treble.  If your speakers exhibit more 'bass' volume while balance hard left or hard right, and sound 'thin' when balanced in the middle, then you have a phasing issue with the way you have them connected to your power source.


Issue: While playing my speakers loudly I heard a ‘pop’ or bang or saw / smelled smoke and now my tweeters / midranges do not work. Now I only get sound from the woofer.

     A; You likely blew one of the capacitors on the crossover. If you inspect the crossover internally, and it looks like a firecracker exploded on the circuit board, then that is the typical visual evidence. Hopefully it went prior to the tweeter or midrange going (even if the driver does still function, the tweeter / mid voice coil may have done some ‘cooking’ prior to the cap blowing up).
A 'blown' capacitor is typically easily repairable by replacing the capacitor(s). To get the correct part value, look at the, hopefully ‘good’ crossover board on the other speaker. This would be a good time to replace ALL of the capacitors on both boards with the highest quality capacitors you can find. Also it’s a good time to clean any attenuators, and inspect / re-flow solder joints and inspect / re-secure the heavier parts such as coils. Also ‘shock mount’ the crossover circuit board to its mounting and possibly ‘seal’ the input panel. A good source for replacement / higher quality speaker crossover capacitors is www.partsexpress.com .


 

Issue: At higher volumes, my sound, especially the bass, seems to distort, especially the bass and / or I get a 'sharp pop or snap' from my speakers...

     A: (See the answer to these issues in the above section on receivers and amplifiers.)




Issue: There’s a light Metallic ‘rattle’ or buzz from one of my speakers, usually detectable at lower lower volumes. (see next symptom below as well)

     A: A ‘light’ / delicate, metallic sounding rattle from a speaker at low volumes is commonly from the voice coil ‘unwinding’. The only remedy is to replace or have the driver re-coned. As of this writing, we are currently refurbishing a pair of Altec, Model Five's that have one of the woofers with this symptom. We first heard it upon our 3k to 20Hz audio sweep, but it was also apparent on some music passages, if you listened carefully enough. Back on the work bench, you could 'tap' on the cone with your fingers and hear the sound.



Issue: My Speaker is making a distorted sound.

     A: A couple of questions regarding the ‘conditions’ of the sound issues / “distortion”?
Is your amplifier past 11:30 or 12:00 (relative to a 'clock face') on the volume control?
Is your ‘Loudness’ control off past about 10:30?
Are / is the ‘Bass Control’ potentiometer not advanced past 12:00 / noon at upper positions on the volume control?
Is the music overly ‘bass heavy’ so that at higher volumes there is distortion?
More importantly, (and likely) is there a combination of the above conditions when you hear distortion?
Does the distortion happen a lower volumes as well as upper, only at upper or only at lower levels?
Is it a ‘tinny’ / high pitch rattle that’s only apparent at lower volumes?
Is it ‘frequency dependent’? (In other words is it only certain notes / frequencies)


With only a few exceptions, speakers usually do not ‘make’ sounds. They ‘reproduce’ them.  Most ‘non typical’ sounds will be coming from somewhere ‘upstream’.
Exceptions are, a ‘farting’ / ‘flapping’ sound from a woofer is commonly symptomatic of deteriorated foam speaker surrounds (VERY COMMON), or surrounds that have separated from the cone or speaker frame, or dust caps that have become separated from the cone, or a torn / ripped speaker cone, or in some cases the speaker ‘spider’ has become separated from the motor front plate. Most of those issues can be fixed by the user with a bit of ‘know-how’ or research.
     A 'lighter', 'buzzy' sound can be from a speakers ‘spider’ wires touch the back of the cone. This can commonly be rectified by ‘tweaking’ the wires a bit so they don’t touch the woofer cone. We have had a few rare instances where the 'spider wires' are becoming detached from, or fatigued at their attachment solder points or fatigued somewhere in between. On those occasions, we've been successful at 're-soldering' them either at the 'terminal' attachment, and / or at the cone. The solder point at the 'cone end' is not something that is ever meant to be serviced, so it's a "last ditch / what have you got to loose" kind of repair. If it works and holds, then great. (soldering 'spider wires' involves scraping / scuffing off the lacquer from the braided wires to get solder to stick and is 'dicey' at best). (we noticed one spider wire issue, but excess movement of it over the other one, when reproducing pure sine waves from our function generator. The wire was barely 'hanging on' at the cone end and was being held by one strand, which was allowing the excess movement. We first noticed 'light distortion' on piano music, then verified the issue with a function gen).
Other 'vibrations' or rattles can be from loose drivers / mounting screws / bolts on the woofer mounting flanges, or midrange / tweeter mounting plates, input plates, crossover components, internal braces, cabinet joints or due to the lack of felt / rubber feet on the cabinet, or even loose / stray material finding it's way into the area of the cone and simply touching  or resting on it (think wood splinters that have worked loose from the cabinet, or grill strings, or insulation or, or, or....
      If you have distortion, snapping, popping or other sounds emanating from the woofer, then you may need to reduce the volume level, 'Bass' tone pot, turn off the 'Loudness' control, and / or some combination of those especially if playing bass heavy music / recorded material.
Some good sources for replacement speaker cones, or replacement foam surrounds to do it yourself or to have it done would be;    
       www.speakerrepair.com  ,  www.partsexpress.com , www.simplyspeakers.com 
(revised 2018)



Issue: Speakers sound 'thin' / lack bass when I select 2 pairs. Each pair sounds fine by themselves, but when I play all four, I get less bass...

     A: There could be a couple of reasons for that. Speakers can sound 'thin' and lack bass when 'combined' either with another speaker or another pair. This will be due to 'phasing' or more correctly, one speaker is 'out of phase' with the other. You can read else where on the web regarding the technicalities / reasons, but here are the likely solutions;
1) Check the speaker wires to make sure that all the connections to 'positives' and 'negatives' are correct (especially if speaker wire has been 'spliced'). If one speaker, or one pair is reversed (accidentally) the bass response will be much reduced.
2) If the speakers have had work done on them, make sure they are wired correctly internally,
3) Some speakers are 'reverse polarity' by nature. These may include some JBL models (especially prior to late 1970's), some early Altecs, and likely others. If you have a speaker that is 'reverse polarity', the easiest way to remedy the situation is to simply 'reverse the speaker wires' at the speaker inputs (you should probably mark the speakers as 'reverse polarity' for future reference).


 Following was from another email I received related to a 'specific' system where a Pioneer SX-880 was being used with two Gemini 1/3 Oct / 31-band 'Semi-Pro' EQ's. 

     "Those 1/3 EQs have sounded like tin cans since the first day I bought them new over 30 years ago. Sad sad sad. oh well...but I love the Pioneer Receiver!!! It's my best friend. Thanks again!!!!

     So "thin" sounding could be a symptom of a myriad of causes.
Are the speakers 'functioning' correctly (involves a few simple tests)?
Is the amp / pre-amp in good health? (I can vouch for that one)
Are the speakers connected in 'Phase'? (meaning are all speakers wired correctly / Positive to Positive and Neg to Neg)
Are the RCA cables in good condition? (swap out for others to test and rare that the RCA interconnects could be the issue)

I didn't want to imply it at first, but while "Gemini" is 'kind'a semi-pro' gear, it's not great gear, but that shouldn't necessarily cause "THIN" sound, and adjusting them should compensate for any "Thin-ness".
On that note, 'Pro-gear' often operates at a 'higher' milli-Volt level than consumer gear. If the EQ's have RCA I/O's you're probably okay from that aspect, but if they are 1/4" I/O's and
you're using RCA-1/4" adaptors, then that's not ideal as they're likely +18dBV In and Out of the RCA Tape Mon jacks, and not -10dBV as most consumer gear.
I can appreciate and utilize myself EQ, and while I do have 1/3" oct / 31 band EQ's in my 'Pro Audio / PA / Studio' systems, I don't utilize them in my 'stereo / listening' systems. I use
'consumer' type 10 or 12 band / Stereo Eq's designed for 'Home Audio' (gets technical, but -10dBV vs +18dBV or even +24dBv I/O levels).
I would 'strip' out the EQ's and start testing from there. A great way to test / trouble-shoot and 'initially do audio judgments' is to utilize 'White Noise'.
You have a source of "White Noise" built into your receiver. Simply select the FM tuner, turn the "FM Muting" OFF, and tune the dial in-between stations
(the lower end of the scale is the best place to find clean 'hiss' (white noise)).
Then balance Left and Right and make sure that the sound from the speakers is 'even' and also a good time to put your ear up to all the different drivers (woofers / mid / tweets)
to make sure that they're all functioning (don't turn the volume up too loud for that as you'll 'de-sensitize' your ears pretty quickly).

Those are some / most of the initial tests and procedures I would try."


Issue: One or both of my speakers are cutting out completely, or their volume seems to be 'coming and going'...

     A: Generally this would likely be a problem with something 'up-stream' from the speakers (ie; amp / receiver / pre-amp or a problem with wires / interconnects / connections), however, we recently had a pair of speakers (Magnet's with dual 8" woofers, a mid and a tweeter) that had one speaker that was just 'not performing well'. It was 'choppy' across the frequency range with no one driver not exhibiting the issue. I assumed it was a problem with my amp / pre-amp. Before I dove into any of that, I decided to take a DCR reading (the speaker was rated at 4 Ohms, so I should see something around "3"). I measured 13.2 Ohms. That's a problem. I started disassembling the speaker, assuming there was going to be something wrong with the cross over or someone had inadvertently wired the woofers in 'series' or something like that. I pulled the input plate and saw 'brown and green' corrosion all over the solder strips that were attached to the binding posts. I got the correct 3.2 Ohms when I measured 'above' the posts and again, 13.2 at the posts. I disassembled them, cleaned / replaced parts, and now I got the correct 3.2 Ohms DCR at the posts. Never seen that exact issue and my speaker tech had not caught it (should have with a 'pre-test' DCR test), only wrote that the tweeters / mids seemed to have "issues".


Issue: The dust cap is dented / pushed in on my speakers. Help. Do I need new speakers...

     A: OK, first off, the dust cap is dented / pushed in on one of more of your 'drivers', not your speakers. The 'speaker' is the entire system of the cabinet and all it's components, ie; cabinet, drivers (woofers, mid's, tweeters, etc), crossover, grill, inputs, etc. Sorry, had to get that out of the way.
So the most correct technique will depend on what the dust cap is made from, how 'picky' you are on final cosmetics, why are you removing it (because the cosmetics of the dent bother you or are you repairing it for re-sale, or are you concerned with how it will affect the sound). Sonically, the dust cap will have more of an effect the closer it is to the size relative to that of the of the diameter of the driver, and / or if it is made of a less 'transparent' material, such as Mylar or aluminum. For example, if it's a 12" woofer, and the dust cap is made of cloth or some sort of material that can 'breath' the dust cap has little 'real' affect on the sound. If the dent is in a 1" Mylar tweeter with a .5" dust cap, then it's likely affecting the sound in a negative way. Certainly if the driver is a 'soft dome' tweeter or midrange' and the entire driver surface is in the shape of a 'dust cap' and it's dented in, it will likely have a substantially larger, negative affect on the drivers intended performance.

     The techniques can involve a vacuum cleaner, tape, small diameter wire / needle, water and vacuum cleaner, or a combination of techniques, or complete removal and possible replacement.

     If the dented dust cap is made of paper (pulp), the we will typically first try a 'shop vac' with a 'reducer' installed to more match the diameter of the dent, concentrate the suction and to reduce overall suction power (too much suction could cause a variety of damages). Sometimes we have to 'wet' the dust cap (usually with water) prior to using the vacuum cleaner (especially as the diameter gets smaller, such as on a JBL LE-25 tweeter or a Pioneer HPM tweeter). A Q-tip or small artist brush works for application. Once dry, you often can't tell it was ever damaged. If the dent is larger, such as on a woofer, the vacuum cleaner technique usually works without wetting. If the dust cap is made of a coated cloth or paper, that is not 'water soluble' then we might try Acetone to soften it up sufficiently (be careful with 'Acetone' as it's a fairly aggressive solvent and too much might soften / compromise the glue holding the dust cap, spider wire attachment, or worse yet the cone / voice coil boundary. Also, of course, follow all the warnings / cautions on the Acetone container).
If the dust cap is cloth with a more 'open' weave, it will allow too much air to 'blow by' and not allow the vacuum to apply enough suction.

     The next technique to try will be to pull it out with tape. This get's a bit trickier, as you need to select tape that will be 'sticky' enough to grab the section you need to pull out, but not so sticky that it causes a layer of paper / pulp to pull off, or makes too much 'pulp fuzz'. We typically will use clear packing tape or 'duct tape' (again you have to be careful with 'stickier' tapes). You also want to try and avoid making the dent worse when you're applying the tape (as you need to apply a bit of pressure to the dent to get the tape to stick in the first place). The 'middle' of a small section of tape is applied to the dent (usually start in the center of the dent). To get nice, even pressure and amount of tape to the dent, we will utilize something that's rounded and hard, and appropriately sized (relative to the size of the dent) such as a 'Sharpie Marker' cap or barrel end (not the felt marker part), or the back end of a 'BIC' pen or similar. The idea is to 'work' / rub the tape evenly onto the center of the dent. Then pull both ends of the tape out (usually 'straight' out and not at an angle to the majority of the dent's surface) with enough force to try and 'pop' the dent out, but not so much that you simply cause the tape to release. Here's the 'tricky / risky' part. Hopefully you don't pull off the finish, cause damage to the finish, rip / tear or remove the dust cap in the process (never had any of the last three happen, but they're possible. Actually if you removed the dust cap 'cleanly', that might be easier, as you could then simply push / press out the dent from the back side, and re-glue it in place (using correct / appropriate techniques). You may need to apply the tape multiple times to get satisfactory results. The tape may remove some of the finish (had that happen to the 'silver' coating on a pair of JBL L166 / 066 tweeters ).

     The next technique is similar to doing 'body work' on a car, or dent removal on a 'brass horn', except on a much smaller scale. It involves making one (or in some cases multiple holes (the fewer, the better)) in select places of the dust cap, and inserting a small piece of metal (needle, paper clip, staple, wire, etc) to 'work' the dent out. My most used version of this technique is to make a small hole with a sewing needle or pin in an appropriate position of the dent / dust cap. Hopefully the dent is fairly centered, so the resulting hole will be centered (actually less noticeable there). I take a small staple (the kind meant for office use / paper), and re-bend it with a loop on one end. I usually will leave the other original in it's original 'L' shape (I might 'shorten' it if necessary). The 'loop' serves two purposes. The first and most important is it will keep the staple from being 'sucked' into the dust cap by the power of the magnet (that would be a 'bad' thing). The other purpose of the loop is to give you something to grab onto with needle nose pliers (or similar). You will use the pliers to manipulate the end of the 'L' on the back side of the dent to 'work' the dent out. As you're doing this, be cognizant of not enlarging the hole or making it 'ragged' with the sides of the staple or the tip of the pliers. Also be mindful of leaving a 'crease' in the finish by applying too much pressure on the tip of the staple. Sometimes this will be unavoidable, or will just happen in the process (it's a learning process to know how much pressure to apply, and in learning how much, you will probably crease the surface, thus it's a 'catch 22'). Once you've removed as much as the dent as possible with this method, you can try a combo of the vacuum / tape to further improve it if necessary. The hole can be sealed with an appropriate glue (such as 'gap filling Super Glue' or a 'black speaker repair glue', or a small bit of just about any type, that will 'stay put' and not add any more than necessary mass to the cap / cone. You can further 're-finish' the glue / hole with a Sharpie marker in black or silver, or a small amount of matching paint).

     Usually one of those techniques will work. If you've tried all, multiple times and it's just not budging, and you REALLY need it out, then you could try removing the dust cap, push the dent out and re-install / re-glue / replace the dust cap (probably best left to a 'speaker repair shop' unless you know what you're doing, but then again, if you already knew what you were doing, you probably wouldn't be reading this).

     Regardless of the method, you may not be able to completely remove all evidence of the dent. At that point you have to decide if it's worth throwing more resources at it. Sometimes they come out 'perfect', sometimes not. It will depend on how long the dent has been there (the longer it's there, the more likely the material will establish a 'memory' and make it harder to remove completely, at least with utilizing only one technique).
In the end it's going to boil down to personal preference / matter of opinion / what you can live with / how it's going to affect the sound / how it's going to affect it's value.



Issue: 
I just picked up a pair of Cerwin Vega 15-inch speakers. Sounds great, bass is tight. I was wondering out the midrange drivers. Do they sound normally quiet ? Sometimes, the tweeters are overpowering the music. At the back, there is only frequency adjustment for the tweets and midrange and no volume adjustment. Could my midrange drivers be bad for both L+R ? Hmm..

      A: Determining if a speaker is 'balanced' takes a very 'well traveled' ear. Sometimes we will even have to use a 1/3 octave RTA to determine if drivers are 'doing their job'. The attenuators are generally for the tweeter's and occasionally for the mid's, but never for the woofers, or for 'overall' volume control. The current potentional would likely be too great for most ‘L-Pads / Rheostats’ to handle, plus speaker mfg’s assume you’ll simply use your receivers / amps volume control for that and the attenuators on the speaker are simply to ‘attenuate’ the top end and / or ‘mid end’ relative to the bass. Mid's and tweeters usually either work or they don't, without much between. "Diminished" output could be related to bad capacitors on the crossover, and if you indeed do have that, then that's where I would look. Hope that helps.


Issue / Question:  Can I play my speakers with them laying on their sides?

 
     A: As long as a speaker is not 'vented' thru the bottom, such as a 'subwoofer' that has a 'down firing' woofer, or a speaker with a 'down firing' woofer (means the woofer speaker is mounted on the bottom plate of the speaker cabinet, facing down to the floor) (and your speaker has neither), it doesn't 'hurt' the speaker. On reason, however that speakers are made with the 'woofer' located on the lower section, and the 'higher frequency' drivers (mids and tweeters) on the top is that 'bass' is 'non-directional', meaning that it will reach your ears no matter where it's located (and you get more bass generally if it can be 'close' to the floor. Tweeters and mids are more 'directional' so it's better to have them 'higher' up in a cabinet, ie; closer to your ears. However, if the location 'works' for you and laying them on their side doesn't negatively affect their sound to you, then go for it. Hope that helps.

 

TAPE RECORDER / TAPE DECK / TAPE PLAYER ISSUES:

(Cassette, Reel to Reel, 8-Track, or any other device that moves magnetic tape such as guitar tape delays, DAT machines, VCR's etc):
 

Issue: My cassette tape deck / 8-track deck makes Gawd awful (motor-boating or loud humming) noise periodically (could be from only one channel, L or R as well).  It even causes the meters to flutter / peg on one or both sides.

     A: Often the culprit is a dirty ‘record’ switch. This is a long switch mechanism, usually located on the ‘main’ circuit board and it needs to be cleaned with a contact cleaner. Solution likely requires a qualified electronics technician / repair person. As a temporary 'fix' you could load a 'recordable' tape, and try manipulating (pushing in and out) on the record switch 10-20 times, and that may clear out the issue for a time. We recently had this issue on the 'Record' side of a double cassette deck, built into a karaoke system, where there was a loud 60Hz hum from the left speaker. Pushing in the 'Record' switch about 2 dozen times fixed it for the time being.


Issue: My cassette tape recorder does not Fast wind or 'eats' tapes.

     A: This is one of the most common symptoms older cassette decks present. This is usually due to a glazed / deteriorated / excessively cracked or otherwise worn ‘idler tire(s)’ / fast wind tire(s) / reel tire(s), and / or the lubrication that has ‘gone south’ (gelled / coagulated / varnished / turned to 'glue' etc). The solution is to recondition or replace the rubber tire and clean the reel hub surfaces for correct traction. Unfortunately these mechanisms are usually ‘buried’ under a few layers of the transport mechanism and may not be easy to get to. The idler tires are usually MUCH MORE important to the function of an older cassette deck than any 'drive belts', although the 'belts' are important in their 'own right'. (Here's something I came across while searching for another issue on the web. There are many varietal examples of this out there, but is typical of what is imbedded in the 'noise of the web',
"Well to be honest it looks like this is getting more difficult than my abilities can deal with. It took me about 6 hours yesterday just to put all the belts on. I felt really burned out afterwards and bummed when I discovered after all that, that yes, it plays now, but still doesn't FF/REW. Maybe I should just throw it up on CL. Still would be nice to have a better working deck then the Pioneer CT-F500 I'm using right now".
'Eating Tapes' can also be caused by something ‘sticky’ that has been transferred to the pinch roller, usually from a ‘contaminated’ tape. Spilled or sprayed soda pop on a tape is the common offender. Also a deteriorating (sticky / tacky / gooey) rubber pinch roller can cause this as well.
Other causes may be a bad ‘fast wind motor’ (if your cassette deck uses one), or a lack of voltage / power to the motor (we recently had a Technics RS-B48R cassette tape deck that was not ‘fast winding’ or taking up the tape when in play mode that was not getting sufficient voltage, but the motor tested OK when external voltage was applied to it).
 (revised 5/2019)


Issue: My cassette tape recorder makes a 'scrunching' sound that I can hear with my ear next to the tape well and it is 'wrinkling / creasing / crinkling' tapes...

     A: So you hear any 'crinkling / scrunching' noises with your ear right up next to the transport, and / or when you pull out a tape that has been played on it, and there is evidence of 'crinkling / wrinkles / creasing' on the tape section that just went past the pinch roller. We have seen this a few times. We don't know necessarily why it does it, but the culprit has been (on the decks we've had and solved it on), a rubber pinch roller(s) that need to be replaced. On some decks, the roller 'looks and feels' fine, but once changed, the symptom goes away. We first came across it on a fairly recent (relatively speaking), Sony TC-850ES, 'Dual Capstan' deck. The deck had two separate pinch rollers. 60 minute tapes seemed to play fine, but 90 minute tapes would develop crinkles / wrinkles / creases passing thru the transport. You could hear it happen if you put your ear fairly close to the transport. Upon further / closer observation, the right pinch roller had gone a bit 'soft', meaning you could press your finger nail into the edge of it, and it would leave a slight 'dent', but only for a moment. The 'left' pinch roller (most decks, unless they're 'auto-reverse' won't have a roller on the left, but as this was a 'dual capstan / closed loop' transport, it did) was very 'shiny' and had gone 'hard'. We changed the left, 'normal sized' pinch roller, and the problem still happed to a degree. Once both rollers were changed, the issue went away. We recently had the issue on a Marantz cassette deck, we had restored a few months back. Immediately following the service, it worked fine for many tapes. We didn't get around to listing it for sale till a few months later. Upon doing a final testing, we found it was crinkling 90 minute tapes (60 minute tapes were not affected). We installed a new pinch roller and the problem was solved.
(revised 2019)


Issue: The tape plays VERY fast on my cassette deck or reel to reel deck...

     A: It's usually caused by the pinch roller / pressure roller not contacting the capstan with sufficient pressure. Normally the capstan / pinch roller is what pulls the tape thru. (Most folks, erroneously, think that the take-up reel is what pulls the tape, but it only serves the purpose of 'taking up' the tape after it leaves the heads / pinch roller). Otherwise tape would simply 'dump' on the floor (or into the case / housing of the cassette shell). There's generally not enough torque on the take-up reel to pull the tape from the other reel, so this problem usually presents itself as the tape 'slowing down'. Your 'take-up' reel has enough torque (probably too much by the way) that it can pull the tape on it's own (which could be much faster than normal play speed, as you're experiencing).

A major cause, is because the pinch roller's upward progress is being impeded. It's likely being impeded by old / aged lubrication that has 'jelled'. Again, this is typical of most 25+ years and older, 'electrical / mechanical' devices. You can test this by putting the deck into play, and with your finger, or appropriate tool / device, apply some upward pressure on the center (non-rotating) part of the pinch roller. If you are able to apply enough pressure to the center bearing of the PR to move it sufficiently against the capstan, the tape should play at normal, or more normal speed. If so, the assembly needs to be disassembled, cleaned of old lubes and re-lubed. This is one of the many aspects we address when we restore / refurbish a tape deck (25-60 year old tape decks are not just 'repaired') for resale. They must be 'restored / thoroughly refurbished'. This is especially fun on decks such as the TEAC A-4010 Reel to Reel 
 and the Pioneer RT-909 / 901. Come to think of it, there aren’t many decks that its any fun to do on, but a ‘must do’ in a list of many other procedures that most 30 year old tape decks need to function to any degree of correctness. (If that's not it (but it should be), then the deck would require further bench time to investigate.)

Another reason can be that the tape isn't threaded correctly. I recently had a Sony TC-355 exhibiting this just after I had played a tape just fine. I pulled the head cover to make sure the tape was seated correctly (can't see much with the head cover in place on many late 1960's thru mid 1970's Sony's) and realized that the tape was not seated all the way between the correct guides thus not between the capstan and pinch roller.


Here's a simple example that recently happened to me due to 'being in a hurry' when threading up a Pioneer RT-1020L. Went to engage 'PLAY' and the deck immediately started playing in almost a FF speed. I 'pressed' down on the pinch roller, thinking that it was getting stuck (the deck had just come out of restoration, so that was not a thought I relished). The added tension didn't help. Tried it again, and of course 'same results'. Sat down in front of the deck to ponder sending it back to my tech, and noticed I had the tape running 'under' the capstan, which on this particular deck meant that it wasn't between the capstan and pinch roller. Re-locating the tape correctly of course rectified my mistake. 

                                                                                                           
                                                                                                               (revised 2024)


 

Issue: The tape plays 'SLIGHTLY' faster than it should on my TEAC 40-4 (or a myriad of MANY other possible decks) reel to reel deck...

     A: In the case of a 'stock' TEAC 40-4 and any other open reel tape deck that utilizes a "Hysteresis" controlled type of motor (meaning that it's speed is controlled from the "Hz" of your AC power source) there's a few reasons this could be happening. 
One would be the "impeded pinch / pressure roller" as discussed above.
Another could be that if the deck was not designed for 60Hz (North American) current, and has a 50Hz motor pulley installed, or if the belt is in the "50Hz" position, and you're using it with 60Hz current, it would play 17% fast. You would either need to source and install the correct pulley, move the belt to the correct position (if that is available), or as a last resort, machine down your pulley the correct amount.
Another reason could be (and is the impetus for the making of this comment) the belt could be 'riding-up' on the 'lip / flange' of the pulley instead of on the proper surface. We recently had this on a 40-4. Probably happened in installation, and for some reason 'slipped through' between final bench testing and final 'sign off' testing. With a hook tool we were able to coax it into place and it's stayed put ever since. A motor being out of alignment at it's 'thrust plate' bolts, either by misalignment or worn rubber bushings / motor mounts could cause the belt to track off and onto the pulley flanges.
(This could also happen on a deck with a 'DC' motor as well. Pretty much any deck that's 'belt drive'. Could also happen to cassette decks and turntables.
 



Issue: Very little of the mechanical aspects of the tape deck functions. It doesn’t ‘play’, Fast Forward or Rewind...
     A: Most tape decks are 30-50 years old with old rubber parts and old lubricants. If you leave a pencil eraser in a drawer for a couple years it becomes ‘glazed’    and will simply slide over paper with no ‘traction’ or tackiness. The same thing often happens to the rubber parts in a tape deck, VCR, turntable or other electro-mechanical device with moving parts reliant on rubber, except it happens in 12-25 years (if it doesn’t harden and glaze, it may try and revert back to it’s original state which is ‘goo’). Secondly oils and greases (lubricants) loose there lubrication properties and actually ‘harden’ as well becoming thick, sticky and ‘glue like’. Both of those issues combine to render most tape decks and such inoperable after 20-40 years. These issues require a COMPLETE overhaul / restoration to operate to any level of usability (8-18 hours typically and some can go considerably longer).  (revised 2018)


Issue: The Auto-Reverse does not seem to work on my reel to reel tape deck...

     A: There could be multiple reasons for this symptom. Firstly does the deck 'reverse' directions, if instructed to do so manually? If not, then there's likely an issue that can't be solved here, and would need deeper investigation, likely by a technician experienced in that mechanism (good luck on that one, as they're 'a dying breed').
      Assuming there's not a mechanical / electrical issue with the mechanism itself, you first need to determine what is the 'trigger mechanism' for the 'auto-reverse'.  Most reel to reel decks required a short (1-1.5") length of 'silver  metallic' tape to be attached near each end of the tape.  This would 'short' two trigger points in the tape path, causing the deck transport to change directions.  Now if you have tapes that have the 'silver tape' installed, you need to make sure it's on the correct side of the tape for your tape deck, and that it's of sufficient length to make contact between the correct pins.  Secondly, you need to make sure the pins are 'clean' and do not have a build-up of oxide (dirt) on them, that could impede electrical contact.
     Other decks, such as Sony's E.S.P. system, looked for 'blank space' in a length sufficient enough to make the 'assumption' that you are at the end of the tape, and that triggered the auto-reverse mechanism.  The length if looks for is approx 8 seconds.  There's a 'flaw' with that system right off the drawing board, in that if a side ends at anything but the start of the lead-out-leader, then you will change directions, and already be into a portion of the recorded program on the opposite side.  Also, if there's a stretch of tape that's 'quiet enough' anywhere else in the recording, the deck may change directions there as well.  Also, if you have a tape that's 'lower quality' or just simply 'noisy', the deck may never get a floor noise level low enough to switch.  That system sometimes works and sometimes doesn't. 
    There's another system that utilizes and optical sensor to determine when the 'oxide' portion of the tape ends, and the leader begins. This is usually found on much 'later and higher end' models. This system works well, as long as the 'optical sensors / and light sources' are functioning, are clean and you have tapes with leaders installed (always a good idea regardless).  It will not work on tapes without leaders.
     Most 'auto-reverse capable' cassette tape decks simply rely on the tape reaching the 'end' mechanically, then reverse, simply based on the tape 'stopping' (triggered by a variety of mechanisms).  I'm not aware of a reel to reel that utilizes this system.
 (revised 2018)


Issue: I have a cassette deck that now does not want to PLAY, FF, or REWIND.  It tries for a moment, but then stops...

     A: There can be a number of reasons for that, including a bad 'main drive belt' (if all of the functions rely on 'one motor and one belt'), or lots of gelled lube, but the most common reason is that there is a problem with the tape counter belt. Many cassette tape decks / recorders / players utilize the movement of the tape counter mechanism (usually with a 'photo optic' or 'magnetic' sensor) to sense tape movement, or more importantly, tape 'non-movement'. When all is working correctly, 'non-movement' of the tape, usually means that it is at it's 'anchored end' on the reel, and the deck either needs to 'auto-stop' or 'auto-reverse' (if equipped with either feature, and most have at least 'auto-stop'). While there can be issues with 'frozen' tape counters, the typical reason a tape counter is not moving is a bad counter belt (it's either broken, stretched too much, or deteriorated). Again, there can be other reasons as to 'non-movement' of the tape, but the first, most likely candidate is an issue with the tape counter belt.  
(revised 2018)

Issue: My Reel to reel will not go into 'fast wind' (fast forward or rewind) or only 'goes slowly' or starts off fast, then slows down, to a crawl, or I have to 'help it'...(but works OK in 'PLAY'* mode)

     A: There are a few things that could be the culprit here. The first thing to mention is that if the room temperature is 'too cool / cold' a unit might perform sluggishly as opposed to how it would perform in a 'warmer' room. Anything in the 'low 60's' F could cause issues with lubes, especially when you consider the lubes already may be 30-50 or more years old, and lubes increase viscosity with lower temps (think about how slow your car turns over when cold, and if you have a manual transmission, how letting the clutch out, even in neutral, causes drag on the engine till everything warms up a bit).

     The next thing (and this is a VERY common issue) to check for is cleanliness of the tape path. If you are playing a tape that is 'stick / tacky' or the last tape you played was, and it left excessive residue on the tape guides etc, then that can and usually will increase 'drag' enough to 'stop' a fast wind motor (or bring it to a 'crawl').  We've seen this numerous times. Solution: Clean the tape path (all the guide pins, tension arms, heads, pressure pads and anything that the tape touches), and don't use that tape anymore. (the reason it doesn't affect play* is that the tape is 'pulled' through the deck by the capstan / pinch roller for play, and for fast wind, the 'reels' do the work. The Capstan / Pinch-roller has a lot more torque, than the reels, especially as more tape is added to the 'take-up' reel (the one that is 'pulling'). *If the 'deposits' are bad enough on the components of the tape path, then 'play' speed will start to be affected.

     The 'fast wind' motors on most 'full size' reel to reel decks are 'AC' motors, and the AC motors in reel to reel's typically utilize 'start / run' capacitors (just like your garage door opener, washing machine, furnace, dishwasher, clothes dryer, bench grinder, air compressor etc). Capacitors go bad with age, and the start run capacitors in reel to reel decks are now 30-60 years old (far past their intended life span) and likely need to be replaced. Barring 'gelled up lube' in the motor shafts, bad / old / aged 'start / run capacitors' may be the issue. Now having said that, I rarely see an issue with start / run caps in reel to reel decks (and I've probably done 150 refurbishments in the past 20 years), but it's worth a try as start / run caps are way cheaper and way easier to throw at a deck, then sourcing and replacing motors. (DIAGNOSING / REPLACING START / RUN CAPACITORS IS A PROCEDURE BEST LEFT TO A QUALIFIED PROFESSIONAL / TECHNICIAN, AS THE VOLTAGES INVOLVED CAN POTENTIALLY BE DANGEROUS, DESTRUCTIVE AND LETHAL!!!)


Issue: My TEAC / Tascam Reel to Reel will not go into 'fast wind' (fast forward or rewind) or play, or anything. Nothing Moves...

     A: There are a few things that could be the culprit here. While some could be issues discussed previously / above, many are likely 'user / operator error'. Yes, I know that hurt's but things like the tape not being fed through it's correct path is a common one. Reel to Reel tape decks not only need the tape to be threaded thru the tape path correctly, but usually to have some tension 'pre-loaded' to 'pull the tension arms 'up' (or at least to the position that defeats any 'auto-stop' mechanisms). This is not just an issue with TEAC / Tascam, but will likely be an issue with any deck. An issue that is 'fairly' unique to TEACS and maybe some TACAMS is that many of the earlier units have an round, multi-pin 'Remote' port on their rear panel. If you do not have the remote (and few folks do), there needs to be a 'dummy plug' inserted into that port (or at least the correct terminals need to be shunted), or nothing on most TEAC R2R decks will move. I've seen techs spend hours, pulling their hair out trying to figure out what is 'wrong' with a TEAC deck, only to hours later discover that it needed a 'dummy plug' to function.
On most Sony's, Hitachi and likely a few others, there's a small 'wire' that 'hinges' up when the tape is threaded correctly in it's path. This 'wire' is part of the 'auto-stop' mechanism. If you inadvertently load the tape 'above' the wire, or it somehow ends up in that position thru changing transport modes, the deck will not play or fast wind. The tape path will need to be corrected to be 'under' the auto-stop wire.


Issue: My TEAC / Tascam / Pioneer (and likely most other, "3-Motor" decks) Reel to Reel will turn / spin the reel on one side. I can hear a motor running when I select the function, but the reel doesn't spin, at least not very well. Everything else seems to work...

     A: This is not a common problem, but can be caused by loose set / grub screws on the reel hub, that secure it to the reel motor shaft. There are one to three of them, and a qualified tech would need to check them (means simply re-tighten them (minding the reel table alignment with the tape path)).
      If the motor does not start or stay running once started, you could also have weak / bad "Start / Run" capacitors on the motor circuit (we see this on Pioneer RT-901 / RT-909 models fairly often).  Or, the motor bearings could be so dry (need cleaning and lube) that the motor is locking up.  
(revised 8/2019)


Issue: My Otari MX5050 Reel to Reel will not turn the reels properly when I have 10.5" reels installed. They simply 'spin' on the reel tables, and / or I hear a 'chatter / clicking' noise. Also when I press "STOP" when 'fast winding' the reel dumps tape / doesn't stop immediately...

     A: Otari made special / specific NAB hubs and 7" reel locks for their machine. If you are using a 'non-Otari' NAB adaptor that pushes into the reel from the front, you have to make sure that you don't have more than about 1/8" of space / gap between the back edge of the reel and the back of the NAB hub surface. The 'tridents' on the Otari MX reel tables are not very tall (they don't protrude as much as most R2R's), and if you're using NAB's that don't come almost flush with the back of the reel, the tridents either won't engage at all or not enough. I've tried a few different NAB's and the Pioneer PP-220 and PP-220A seem to work well with our Otari Reel clamps.


Issue: My Reel to Reel dumps/spills tape / doesn't stop immediately when I press stop, BUT only on certain tapes...

     A: The condition of the braking mechanism (specifically bands, shoes, pads etc) may be at fault, or the brakes may need to be adjusted, or both. We recently had a Sony TC-730 that would brake fine with 'plastic' tape reels installed, but with Maxell aluminum reels on both sides, it would spill tape if stopped during fast wind about half way thru the tape. The aluminum Maxell reels weighed about 2.5 ounces more each than the plastic reels which was enough to make a difference. We adjusted the brakes for the metal reels and all was then good.

Issue: My Sony TC Reel to reel or Teac A-4010 and others of this style does not ‘pull’ the tape through in ‘Play’ mode...

     A: The Teac A-4010 and most Sony ‘TC’ series R2R’s are over 35-50+ years old (actually there are no ‘Real’ Reel to Reels made since about the mid 1990’s ("NO", that ‘strange’ 1/8” RCA made about a decade ago doesn’t count, sorry) and like most R2R’s, they have gelled / varnished lubricants. The A-4010s’ pinch roller is on a ‘pivoting’ arm mechanism and will invariably be in some stage of ‘sluggishness’ up to completely ‘frozen’ and immobile. The only solution is to remove it (usually requires heating the bushing either with a 'large' soldering gun or a 'focused' heat gun or similar), completely cleaning and re-lubing. Once done, it will be good for another 20-40 years. The Sony requires a similar procedure, but has a lot more parts, and is more complicated to disassemble, then to get it all back together correctly.
One 'temporary' test you can do to prove that the above is the issue is that you can 'push' up on the pinch roller at it's center to see if that then allows the tape to pull thru at the correct speed. You may be able to put something in the center, or your fingernail against the hubcap if there is one (and there usually is).
     I will correct part of the statement above. There IS a NEW reel to reel being made in Germany  http://www.ballfinger.de/tape-recorder-m-063  
(revised 8/2019)


Issue: The tape tends to 'track off' or skew out from the pinch roller / capstan on my reel to reel tape deck...

     A: While many tend to blame the 'pinch roller' or bent or skewed tape guides, I have usually found this to be the fault of improper 'back tension' on the supply reel and on a couple of occasions, too little pinch roller pressure. You can test that theory by applying a bit of 'caliper braking' action to the outside edge of the supply reel with your fingers while the deck is playing. Not much, just a bit, and the tape will usually come back into alignment. Unfortunately, this is not usually an easy thing to correct. On earlier decks, such as Sony's, it's done with a clutch made of felt, on others, with brake pads. On 'single motor' decks that don't have any adjustment, adding some 500,000 grade silicone lube can sometimes do the job. On later, 3-Motor decks, it's typically done with a small amount of 'reverse' voltage applied to the 'supply reel motor' (not something to mess with unless you're qualified).
     If the back tension is 'maxed', you can still affect it with adding pressure with your fingers, then it's likely lack of 'pinch roller' pressure. You can test this theory, by adding pressure to the pinch roller, towards the capstan. If you're able to do it quickly enough when you see the tape 'start' to skew, and the added pressure pulls the tape back to the correct path, then you've probably determined the problem. Some decks may let you adjust pinch roller pressure (such as 'three motor' units), some may not (single motor models).
Regardless, any of the measures to address the 'tape skewing' symptom, any repair is not particularly 'end user friendly' is beyond the scope of this page. You'll typically need to seek professional assistance for that one.
(revised 2022)


Issue: My Reel to reel won't pull the tape through, or tries to 'dump / eat' tapes, or won't pull the tape through very well with certain 'leaders' attached, but works once it get's past the leader section...

     A: Yes, we recently came across that ourselves with one certain type of leader (freshly ordered and installed 'white' leader) on a Sony TC-580. There were no problem with other leaders (Maxell UD-XL or TDK Audua as examples), or with 'leader-less' tapes. Only the tapes with the 'recent / new white' leaders installed. We don't know why or what the 'fix' would be. We simply have to 'manually' help the tape come through the leader by spinning the take-up reel till it gets past the leader section.
(revised 2018)
 

Issue: My Tape deck doesn't 'RECORD' onto the tape...

     A: This one will definitely be a "work in progress", as there's a myriad of reasons / causes for this. I'll touch on them as they come to me.
1) Do you have signal all the way up to the tape deck (multiple ways to verify that).
2) Most decks require you to press the "RECORD" switch(es), while you press "PLAY". There were some later (think late 1980's and newer 'Cassette Decks' that had a feature called "OTR" (One Touch Record), but early decks did not.
3) If you have a 'Three-Head' deck, make sure you have good signal when selecting "SOURCE" on the tape deck. That is also the initial level to set your 'Input' controls with.
4) Are you confident you have 'known good' RCA / DIN / Interconnect cables?
5) Is the 'Record' adequately head clean?
6) Is there a chance (applies to Reel to Reel tape) that the tape has been 'inverted' and you're trying to record on the wrong side
7) I recently had a tape that simply would not record. Tried it on two different R2R decks. Switched to another of the same brand and model of tape, and it worked perfectly.
8) Is there a chance (applies to Reel to Reel tape) that you have "EE" (Extended Efficiency) tape that you're trying on a 'non-EE' deck? If so, you won't get much signal transfer to it, and it won't erase the previously recorded tracks very effectively.
     Beyond the above (and again, I will add more as it comes to me), you may have a technical issue with the tape deck, ie; dirty / intermittent 'RECORD' switches (try manipulating them repeatedly and see if symptoms improve),  a wire or internal connection that has become compromised (commonly the connections at the head, but would be very odd for 'both' channels to become disconnected),  open coils on the 'RECORD' head (VERY rare to have happen and again, even more rare to affect 'both' channels),  internal issue with circuitry (beyond the scope of this conversation). 
(revised 2019)
 

Issue: When I PLAY tapes on my reel to reel / cassette tape deck / 8-track deck, etc, the sound is fairly 'muffled' / muted / dull...

     A: Dull / Muffled sound when playing a tape can be from a number of causes. First would be to question / verify the quality of the tape and / or original recording, but for the purpose of this writing, lets assume you have a tape that's of 'reasonable' quality (I would check it against a number of tapes to verify that more solidly). Older, or 'poorly recorded' tapes, or 'lower quality' tape formulations / brands can sound muffled, or have 'drop outs' in the signal, so you want to rule out any issues stemming from the tape itself. Also, regarding reel to reel tape, another 'tape related' issue can be, is there a chance the tape is inverted (on upside down (or in the case of an 8-track cartridge or cassette tape, 'twisted' somehow))? This is usually indicated by 'muffled sound' and likely playing 'backwards'. This does happen for various reasons, and may take some 'thinking' to rectify by a combination of inverting and fast winding the tape once or twice to correct the issue. Beyond issues with the tape itself, probably the first thing to look at is the cleanliness of the playback head(s). From a 'cleanliness' standpoint, there should be no oxide build-up from tapes, no corrosion, or anything. If there is, then they should be cleaned. This is usually best accomplished with a good head cleaning solution, or denatured alcohol and cotton swabs. Never use anything abrasive or with a hard edge. The heads should be cleaned fairly regularly anyway.
      Are the controls set correctly for maximum sonic quality?  If Noise Reduction such as 'Dolby' is being utilized, that will diminish top end response. Are the 'Tape EQ' switches set correctly (generally have more of an effect on recording, depending on the deck). If the tape was recorded at a slower speed, the high frequencies may be reduced beyond what you're used to if you normally play tapes recorded at 'higher speeds'.

Dropouts / 'cyclically muffled' sound: This effect / issue can be caused from a number of situations, but was likely due to the tape being exposed to a 'magnetic field'. Examples of this can be from a vacuum cleaner motor ran too close to them, a furnace motor (I had this happen to most of my cassette collection that was stored in racks, mounted on the wall, that happened to have the F.A.G. furnace located just on the other side of the wall), someone storing or sitting their tapes on just the 'right' speaker, in just the 'right' way (this one happens often), tapes sat on top of a TV or near it's power supply (magnetic flux from it's power transformer). Another example of how this can happen is someone owns / utilizes a bulk tape eraser, and isn't cognizant of other tapes in close proximity. 
     Another potential cause can be tapes that exhibit 
Wrinkling / wrinkles  (wrinkled tape / warped tape): Occasionally a tape (typically applies to reel to reel tape) will appear fine while tightly wound on the reel, but as the layers come off (often for the first time in decades), the tape will develop a ‘wavy’, wrinkled appearance. If the wrinkles / waves are ONLY near the first couple of layers, then it might not be an issue, but depending on multiple factors, it quite likely will continue throughout the tape. This usually renders the tape ‘un-listenable’, at least from any kind of decent quality standpoint, as the ‘waves’ will cause the tape to cyclically come away from the tape playback head, causing a ‘drop-out’ effect in the sound. Sometimes only one half of the tape will be affected, and the other half may sound fine.
     One possible solution that may be acceptable for 'wrinkled tape syndrom' is to use a deck that applies pressure to the outside surface of the tape, thus pressing it firmly against the playback head for a more ‘even’ coverage of the head by the tape. Many Sony reel to reel tape decks made from the mid 1960’s into the early ‘70’s have a small metal ‘tab / plate’ with a felt pressure pad affixed that does just that. If you can acquire one of those decks that have been restored / refurbished to functioning condition, that may suffice. Barring that, you could try and apply pressure manually in some manner. Again, any method of applying pressure to the tape to try and negate the effects of ‘tape warp / wrinkling’ is at best a ‘better than nothing’ solution.
Depending on track format, and your need for that tape / recording, you’ll have to decide if it’s a ‘terminal’ issue.


The next issues become a bit more involved to rectify and may require a qualified technician with correct test tapes, tools and test equipment. Also, due to the effort involved in the next remedies, replacing the tape deck with a quality, competently serviced one may be a better solution.
     Look at the condition of the head to tape surface. If there is excessive head wear, then the sound will be lacking the high frequency it should to the degree of head wear. It may also exhibit proportionally less overall output. This can be due to 'head gap' widening, but is more likely from the tape being 'held' away from the head, by the edges of the channel that may be worn into the head. The tape may 'ride' up or 'curl up' the edges of the 'channel' and pull a few microns away from the head (yes microns make a big difference when it comes to magnetic tape reproduction quality). To determine if you have excessive headwear (and most decks do have some degree of tape head wear), look at the 'shiny' surface of the heads. There may actually be a visible flat spot worn into the apex of the. If you run your fingernail over the head from top to bottom, you will likely feel the edges of a channel that has been 'cut' by the tape. The degree of this cutting action / depth of the channel will determine the amount of sonic lose. It usually takes substantial wear for most folks to have an issue with the sonic characteristics of worn heads. If 'head wear' is the culprit, then there are two options. The first and most common (at least in the 'old days') would be to have the heads 'lapped'. Lapping heads is not a process for the un-initiated and is a fairly 'lost art' today. If lapping your heads is not in the cards, then replacing the heads may be the next remedy, although finding heads will not be easy either, nor getting them correctly installed.
     The next more common issue and easier to approach is to adjust head alignment / azimuth. If the head Azimuth is 'out' of adjustment, then that will cause diminished high frequency response and / or overall output. While it is possible to get the alignment / azimuth 'fairly close' or maybe 'close enough FOR YOU' by ear, to do it correctly requires official alignment tapes and test equipment such as a dual-trace oscilloscope (that's what we do it with).
     Another possible cause of diminished output, although a cause only attributable to a 'handful' of tape decks, would be worn felt pressure pads. Remedy is to replace the pad with a correct part and realign it correctly upon installation.
     I suppose an additional reason could simply be that you're applying a 'Noise Reduction' system, commonly Dolby. Even if a tape is encoded with Dolby, you will still typically notice a reduction in high frequency. Or if you have a 'high filter / treble filter' engaged on your pre-amp section. Turning those off if 'inadvertently' engaged may satisfactorily improve the sonics for you.
     You could of course, have a combination of the above issues, so the issues would need to be attacked in the correct order. If you have 'excessive' wear, then likely no amount of adjustment will compensate for that. If you have excessively dirty or corroded heads, and you don't rectify that, then adjusting will not likely help. If your tapes are the cause, then nothing will likely help, at least not at the tape deck level.
     Lastly there could be an electronic issue with internal playback amps, and level controls. These again, are not generally 'user' addressable solutions.
(revised 2019)


Tape Deck:
Issue: sound starts off quiet / muffled then volume increases and sound improves after it plays for a few moments...

    
    A: This is usually caused by the mechanism that moves the tape head up into it's play position being 'sluggish', which will likely be due to stiff lube / grease (similar to the issue with the Pioneer RT-909 mentioned above). The old, stiff lube needs to be cleaned and the mechanism needs to be appropriately re-lubed (similar to the issue that plagues Pioneer RT-901's / RT-909's and TEAC A-1000's, A-1200's, A-1500, A-4010's and 6010's and other similar decks pinch roller arm mechanisms).
 

Issue: When I play my 'small / transistor / pocket / portable / mini reel to reel player / recorder, the tape playback tends to speed up / increase or slow down / decrease / pitch changes as the tape progresses...

     A: In the 1960's and early 70's, small / transistor reel to reel tape recorders were abundant, especially prior to the prevalence of the 'cassette' format. They were especially utilized for 'letters to home' with GI's and their families sending 'taped letters' back and forth, to and from Vietnam. The reels were easily mailed due to their 3" and smaller size. Interestingly, some of the 'lesser' quality / cheaper priced decks did NOT use a 'pinch roller / pressure roller' to pull the tape through as most reel to reel tape decks did. They simply relied on the 'take-up' reel to pull the tape across the heads. This technique was known as 'rim drive'.  Other than being a fairly 'un-reliable' way to move the tape, it did not present a speed problem as long as you played the tape back on the same deck it was recorded on, or another deck of the same design. However, if you recorded a tape on a 'normally designed' tape deck with a capstan / pinch roller
(a 'capstan / pinch roller design' maintains a constant tape speed) and then tried to play it on one of the cheaper / 'non-capstan/pinch-roller' decks, the tape playback speed would increase 'gradually' as the tape spooled from the supply reel to the take-up reel (this is due to simple physics; as more tape fills the 'take-up' reel, it's diameter increases, thus causing the speed at which the tape is pulled across the heads to gradually and continually increase). If a tape were originally recorded on a deck without a capstan/pinch-roller and it were played on a deck WITH a capstan/pinch-roller design, the tape speed will be 'perceived' to be slowing down (read the above and deduce why from that). Thus if you are going to be playing the 'small' tapes that were likely recorded on a small / transistor / portable tape deck, it helps to know which tape transport design the deck had. Again, most of the better / more expensive decks used a capstan / pinch roller. The cheaper decks omitted those parts.
(since the speed increase / decrease is 'gradual and constant' transferring to computer and then trying to adjust playback speed / pitch is not really practical)
(revised 2018)



Issue: When I try to change tracks on my 8-Track tape player / deck, the track indicator lights flicker or don't come on at all when it switches...

     A: There are a couple of possible reasons for the issue. Either the lights are burned out, or the internal contacts on the 'track change mechanism' are corroded. When we are restoring decks, it's standard procedure to replace all the indicator lamps. Having done that, it's VERY common for the contacts that allow the lamps to light when the tracks are changed to be corroded. We will disassemble that mechanism and burnish all the contacts (re-springing them if applicable). That will usually fix all the issues with the track indicator lamps not glowing.


Issue: My reel to reel tape deck is 'noisy' / has a lot of motor / mechanical noise...

     A: There can be a lot of contributors to a deck that seems excessively noisy, mechanically. The motor may need to have it's bearings / bushings cleaned and re-lubed. That would generally mean a complete disassembly of the motor which is typically quite involved. If the motor has already been cleaned and re-lubed, and it still seems to be the source of excess noise, then do the process again, utilizing a higher viscosity lubricant.
      The motor mounting components may need to be assessed. There may be rubber components that need to be replaced or 'improved upon'.
      We've had a couple of engineers suggest changing the 'start / run' capacitors. We've tried that on a couple of machines to no avail.
      If it has 'idler tires / driven wheels' the rubber will definitely need to be resurfaced / reconditioned / rebuilt. Their bushings also need to be cleaned and lubed properly. The idler tires can sometimes have 'run-out' (be 'out of round'). That can typically be visualized or 'felt' and will be 'cyclical.
     There may be other mechanisms / assemblies that are vibrating sympathetically with any noise being generated, thus adding to the 'chorus' or 'amplifying' what's already there. Anything buzzing, vibrating, rattling etc will need to be damped by some means that doesn't interfere with the operation of the unit. The housing / case / enclosure can also be an 'amplifier' for any noise generated. Internal damping material can help there or some method of isolating it from it's environment such as our 'Sorbothane' isolation pods.
     Sometimes, there's nothing that can be done. Some decks are simply noisier than others. In those cases we've been able to reduce the noise, again by utilizing our our 'Sorbothane' isolation pods.
(revised 2018)


Issue: Reel to Reel tape deck records signal that 'comes and goes' / cyclically increases and decreases in strength and the tape appears wavy between the tape guides and heads...
(this was not an emailed question, but an unusual issue we experienced here at the shop on a recent restoration, specifically on a Sony TC-580)

     A: Before I directly address the specific issue above, there is a somewhat similar symptom that has a completely different cause from the 'fix' for the above. Some older reel to reel tapes will exhibit crinkling / wrinkling / waviness as the tape is un-wound from the supply reel. The tape will appear fine initially while wound tightly on the 'supply' reel, but as it 'peels' off, it becomes quite 'wavy'. This waviness will appear throughout the entire length of travel thru the tape path. The act of the tape winding onto the take-up reel will not improve it, and the tape will retain the waviness. This in turn will inhibit it from winding tightly / flat onto the take-up reel, which in turn will mean that the tape will now not likely 'fit' onto the take-up reel anymore. We are not aware of a 'fix' for this. There may be a 'baking' technique that can address it. To at least play the tape to a possible acceptable level, a deck with 'pressure pads' can help. Most decks do not have 'pressure pads' in front of the heads, but quite a few 'late 1960's' Sony decks did.
      Now on to the original query. We had never seen this particular issue. When recording a signal, the one of the playback meters was immediately showing a cyclical increase / decrease in the recorded signal (it was a "3-head" deck so this was quick to observe, and of course the 'incoming signal' was not showing the issue on the meters). Upon closer observation we also noticed that the tape was twisting back and forth between the innermost tape guide and the pinch roller (think of the
Tacoma Narrows Bridge in Washington State, often referred to as Galloping Gertie (video link) that collapsed in 1940). The pinch roller had already been reconditioned via the method we recondition all of our pinch rollers, but it was still the most likely culprit (this was an 'Auto-Reverse' capable deck and we observed the issue playing in the reverse direction, although not as pronounced). I had the tech pull the pinch roller and with it in an engineers square, we could see the it was not perfectly true / 90°. We discovered that the surface of the tool we reconditioned with had 'gone south'. Once the issue with the tool was rectified and the pinch roller re-resurfaced the problem was solved. (revised 5/2019)


Question: "I have a Nakamichi 582 cassette deck and I'm planning to put that amongst other components in a vintage stereo cabinet... problem is the only way to get all my components to fit is to mount some of them vertically (faceplates facing up). Do you think this might cause any mechanical issues if I do this with my cassette deck? Would you recommend against doing this?"...

     A: I'm not aware of any cassette deck that would have an issue or problem playing in a position other than 'horizontal'. Some Reel to Reels could have an issue if their 'tension arms' rely on gravity to function properly, but cassette decks do not utilize those. The only issue I can think of would be if the capstan flywheel(s) have worn or missing or insufficient 'thrust bearing surfaces' it could create noise, but that would be a problem in and of itself, and not to do with the physical orientation of the deck / transport.


Issue: When I try to change tracks on my 8-Track tape player / deck, it won't change, just clicks...

     A: The playback / record heads are mounted on a vertical post that allows the head stack to move vertically to the different track positions. This is done by a 'ratcheting / cam' system. Time is not a friend to lubrications in any thing, including tape decks. Most moving parts are going to have lube's associated with them, and those lubes have likely gelled / hardened to a degree somewhere between 'slightly less slippery' to completely varnished / hardened solid or near solid. The lubes of the head mechanism on an 8-track cartridge tape deck are no different and will need to be completely removed / cleaned off and replaced with the correct lube. That is part of the restoration process we do on our own decks we sell.

Issue: The tape counter on my Pioneer, Realistic etc 8-track doesn't work. I've changed the belt, and the belt is fine, but the counter won't turn...

     A: . I could sell a ‘truck load’ of 8-track counters if I had them, as they ALL, (pretty much across the brand / model board) are either broken or on the verge of breaking (maybe not today or tomorrow, but it will happen sooner than later). They all are plagued with a nylon ring gear, on a steel shaft that has cracked due to shrinkage. When the “Ring gear” rotates to the ‘split’ point (allows that space between those two teeth to widen) it won't mesh properly with the worm gear’ the counter locks up. Best to forget about a counter, remove it, and put some black, vinyl tape over the openings.
(ps; on the rare occasion we have a 'working' 8-track counter to sell, we warn the purchaser that it's probably 'not long for this world'. We also tell folks that purchased restored / serviced decks from us, that occasionally have 'working' counters, the same thing.)


Issue: My tape deck doesn't play from one side, but the meter is responding to what should be on the tape, just no sound / output to my receiver / headphones...

     A: So this was an odd call we had the other day, but a fairly easy one to troubleshoot. Generally (I actually can't think of an exception) if you have Tape Playback signal that excites the meters (and you're not monitoring 'Source') you should have ample signal to the outputs. There's not much reason it could be the tape deck. About the only reason you wouldn't is from a compromised solder joint or wire (unlikely). The problem is likely downstream from the tape deck. In the case of this call, the user was monitoring only with headphones (actually connected to the RCA outputs of a Sony TC-377 Reel to Reel then to a headphone amp, computer etc). He then connected to the headphones to the front panel headphone jack and was still missing one side. I suggested he try another pair of headphones, and that fixed it. He had a compromised pair of headphones.


Issue Regarding Akai 4000 Series reel decks and their speed sleeve: "Hello. Before ordering. First let me ask you a question. My name is Alexandtru, I live in România în Europe. I previously had four Akai GX 4000D tape recorders. All have deviation at speed by 1% more. With a recorded test tape instead of 700HZ I have 707HZ on the oscilloscope. I mentioned that I have asked other GX4000D users, and the same problem. From what I understand there is a common problem with them with original SPEED SLEEVE.
The question is. If you know about this problem and do you make SPEED SLEEVE with the fixed correction. Because the original one gives a deviation of 1% more. Thank you! Alex D."

     A:  Hi , Thanks for visiting oaktreevintage.com. So, I am familiar with the 4000 in all its different iterations. We have restored / refurbished a few of them over the years. I actually like those machines from a standpoint of being a design that lends itself to successful restoration, HOWEVER, it is a lower/mid line ‘consumer’ grade machine with an “AC current” capstan motor. It appears that you are maybe trying to utilize it for your music production company.? I am not familiar with any scuttlebutt out there regarding them always playing “fast”, but maybe…? Firstly, are you sure your test tape is correct? We have about a dozen different test / alignment tapes we use here at the shop, and NONE of them are exactly the same as any other when it comes to speed. We have 2 or 3 that are very close to each other that we switch between.
     So I pulled the worksheets for all the “4000” decks we’ve done over the years and in looking at their ‘post restoration’ speed tests with a 1kHz tape, I see the following results; 1005Hz, 1004Hz, 993Hz, 995Hz, 1010Hz, 1001Hz, 999Hz, 986Hz, 997Hz, 980Hz, 993Hz & 1009Hz (didn’t realize we’d done so many).
There is no mechanism on that deck for adjusting / fine tuning speed. In fact, the service manual only mentions “speed” regarding “speed deviation” and the way they suggest to test for that is to take a measurement at the beginning, middle and end of the tape. Now I don’t know what length the official Akai test tape at the time was, but likely not a long as a normal 1200-2400’ tape. I can’t imagine their test tape being long enough to matter, but if you had a normal length, blank tape (1200-2400’), the amount of force required to pull the tape thru would change throughout the travel of the tape.
You could machine down the flywheel or further machine down the sleeve if you’re convinced that your test tape is accurate (we actually did that once on a Sony that was -30Hz at 1000Hz (meaning it was playing at 970Hz). We took the flywheel to a machine shop to get it milled down {and they said they did not want to do that again as it was a “pain”}). Frankly if you need it to be that critical, I would get a machine with a ‘DC’ motor and either in internal, or external or both fine tune / pitch adjustments. Then you can get the machine say, at 1000Hz to be 999Hz to 1001Hz or maybe even better.
As far as our sleeve, they’re definitely “consumer grade”. It is always a challenge on every batch over the past 25 years of making them to get the machine shop to get them as accurate as possible. There have been many times that we’ve had to have them re-worked multiple times to get them as close to perfect as possible. If you have an original, I would just stick with that (assuming you’re still set on using an Akai 4000 series).
If you still wish to get one of ours to add to your tool box (but frankly it won’t be as accurate as an original from a speed or Flutter standpoint), then here's a direct link to our “Akai / Roberts Speed Sleeve” page that shows those (As there are multiple speed sleeve versions for many different Akai / Roberts models shown on the page, Scroll or search to locate your model listing on the page for the correct speed sleeve):

http://www.oaktreevintage.com/Akai_Reel_Tape_Deck_Capstain_Speed_Sleeve_Replacement.htm 

Just let us know any further questions you have once you view. If you wish to place an order, please do so directly from the ‘Buy Now’ button on that page. We are always looking for more stuff. Keep checking as we never know from day to day what will arrive. Good luck and thanks again,
Jerry at www.oaktreevintage.com
 

AM/FM STEREO TUNER / RADIO ISSUES:
 

Issue: My Stereo Tuner / radio has bad reception, or doesn’t pick-up stations strongly.

     A: Are we talking AM or FM?

    
If you are referring to AM: First of all, stereo receivers are not known for having stellar AM performance in the first place. There are a few exceptions to that, but generally that's what's experienced.
Having said that,
if the receiver has a rear located ‘stick’ AM antenna, change / manipulate the position of the built-in ‘stick’ antenna located on the rear of the unit (some receivers have the ‘stick’ inside and there’s little you can do about it’s position). If it has a rear located ‘stick’ AM antenna, there usually an adjustment screw inside the end of the antenna 'stick' housing (or slider with a button on the side). You can try adjusting slider / screw for better reception. Some later model receivers (after about the early 1980’s) most tuners / receivers switched to a detachable ‘loop’ style AM antenna. This is more easily manipulated, but in my experience does not typically perform as well as the older style ‘stick’ type antennas. The best solution may be to install a high quality external / roof mounted antenna (rarely seen these days).

     If we are talking FM: Is an antenna installed at all? I can’t tell you how many times folks call with an FM reception issue, and they have no antenna installed at all (called not reading the owners manual). Or they say, "Yes, it's that little 'stick / bar thingy' in the back...right?". No, that's the AM antenna. Most receivers / tuners do not have any type of FM antenna ‘pre-installed’, but do have connectors on the rear. The simplest (read cheapest) solution is to obtain a simple 300-Ohm, ‘Folded Di-Pole’ antenna wire and connect it to the antenna barrier strip screws on the rear on the stereo receiver / tuner. Traditionally this wire antenna is ‘tacked’ up on the wall behind the tuner. Even though it’s less than a $10 fix, this is usually more than sufficient for 95% + of listeners needs. For even better performance, again a more expensive, ‘externally’ mounted / attic / roof mount antenna can be obtained. Many ‘old school’ TV antennas, had / have FM capabilities.
     For some reason, the general public has forgotten the importance of an antenna to pick up radio stations. In the 1930’s thru the 60’s I would say everyone from kindergarteners to grandmothers knew the importance of an antenna. Nothing in physics has changed and they are still just as important.
     If none of the ‘antenna approaches’ improve the situation, your ‘vintage’ tuner likely needs to visit a technician and be at least ‘re-aligned’ as 30+ year old components have most likely ‘drifted’ in value from when the tuner was originally aligned. A technician may discover other issues as well, but typically a general cleaning and basic alignment is all that is in order. Actually the cleaning / alignment was probably in order regardless of what antenna solution you chose.
     Tuner issues can be ‘challenging’ to even seasoned technicians and require skill sets and test equipment specific to tuners that not all technicians possess.

Recent email we received regarding reception;
Question; "Good morning, I have a Pioneer SX-2300 Receiver for which I need a new antenna. I only have a turntable and speakers hooked up to this unit. Turntable sound and speakers are great. But trying to maintain an FM or AM station is sketchy. Any ideas on how to maintain consistent output? Thanks! Kate"
      My response;  "Thanks for visiting oaktreevintage.com. As far as “FM”, Normally you would use something that looks like this and it works fine for 99% of folks:

https://www.amazon.com/Bingfu-Terminal-Bluetooth-Receiver-Amplifier/dp/B07MG2XYR6 

If you already have one like that, and it’s still not working, AND the tuner portion of your receiver is working correctly, AND you’ve moved the antenna around with no good results, AND there are FM stations within a practical distance to pick-up (say less than 50 miles or so), AND there’s not mountains / buildings blocking the signal, then it gets more complicated. You’d need some sort of mast with a much more elaborate antenna connected and / or an electronic amplifier possibly.

As far as AM, most of the above still applies, except night time is better than daytime and AM can travel further distances, and not typically affected by obstacles as much as FM. FM typically works better on cloudy days (as the signal bounces off the bottom surface of the cloud water vapor somewhat), and AM works better in clear weather, again especially at night.

Normally just a piece of wire a few feet long works for "most" folks for either FM or AM. Good luck and thanks again,
Jerry at www.oaktreevintage.com

PS. Here’s a kit for FM and AM on Amazon if you have determined that you don’t have the proper antennas;

https://www.amazon.com/Antenna-Ancable-Pioneer-Marantz-Receiver/dp/B07Y7ZM4XM/ref=pd_lpo_2?pd_rd_i=B07Y7ZM4XM&psc=1 "
 

 

Issue: My (solid state) Stereo Tuner / radio has a lot of noise / buzz / hum when on AM stations.

     A: There are numerous reasons / causes for extraneous noise when trying to listen to AM 'specifically'. Assuming you have an adequate antenna, AM reception quality can still be anything from 'non-existent' to very clear, and can vary from time to time. As we all know (or should know), AM reception is better at night than the day (you can research the reasons why on plenty of other web destinations). Thunder storms are the typical cause for intermittent static, but as far as a constant 'buzz or hum', that is usually caused by a 'local, environmental' source. Some common ones are nearby fluorescent lights (including CFL's), sodium lights (we have that issue in our warehouse here at Oak Tree Vintage) and TV's with CRT's (picture tubes), electric motors running nearby (shavers, blenders, coffee grinders, blow dryers) etc. There are probably plenty more, but that should get you thinking in the right direction.


Issue: My radio receivers’ / stereo tuners' tuning string is broken and the dial pointer won’t move

     A: While this may not seem like it should be, this can be a fairly ‘serious’ / pain in the ‘you know what’ issue. If the tuner string has not gotten moved from its’ original ‘path’ you may be able to ‘retrace’ it with a new string. If you cannot retrace the exact path, or at least source an original diagram from a service manual showing how to restring it, then it may be almost impossible to repair correctly. Even if you do manage to get the ‘path’ correct, getting the correct tension back is also very difficult. Finally getting everything back in sync is the final difficult step. I don’t want to ‘rain on your parade’ too much, but I can’t tell you how many times I’ve been approached by someone wanting to sell me their stereo receiver saying something like “all it needs is a new piece of string on the dial”.  That’s right up there with “all it needs is a couple of little knobs, and you can get those down at Radio Shack”. NO YOU CAN’T and if you're trying to bring a unit back to original condition, those issues really become and are BIG DEALS!  

‘Antique Electronic Supply' has replacement string (yes it is ‘special’ sting) and their website is:  www.tubesandmore.com . There are some ‘Radio Restoration’ books out there that have a number of different ‘string path diagrams’ for some of the antique radios that might be of some use.
 




Issue: The ‘tuner’ knob on my stereo is very ‘stiff’ or won’t move at all, or you used to be able to give it a 'spin' and the dial would travel most of the length of the scale, not it stops after 1 or 2 revolutions...

     A: We are seeing this more often as of this writing (revised Jan 2019). After 25-50 years or more, flywheel / tuning string shaft lubes will have become gelled / gummy / varnished. I have actually seen them bad enough to completely ‘freeze’ the shaft in it’s bushing and then someone tries to turn it with so much effort that they can actually ‘twist’ off and break the tuning shaft. Recently we were 'coming down the home stretch' on a Pioneer SX-580, and the flywheel 'froze up' and wouldn't move. Prior to that it had been moving decently fine. It will need to be disassemble, cleaned and re-lubed (be careful in disassembly to note how the EXACTLY how the tuning string is wrapped so that string can be CORRECTLY re-wrapped and re-tensioned). (On the previously mentioned, "SX-580", we could not get the bushing / axle disassembled. We applied heat and still could not get the two parts separated. Fortunately we had another 'salvage / donor' Pioneer SX-580 to pull the flywheel from. Interestingly the spacing on the two were slightly different (even though they were the original parts, from the same model), so the replacement had to have a couple shims added to clear the front face of the unit.)
     We are seeing this as an issue more often (as in quite frequently now) than in past years, again, I can only assume it's because the lubes are hitting the end of their useful life. If you are going to undertake the job of cleaning then re-lubing it, do it before it completely 'freezes' up, and that can happen within the span of a few 'revolutions' of the tuning knob.
Hey, once it's done, it should be good for another 30-50 years. Yee-haw!
(revised 2019) (3/16/2021: just had the same symptom on a Concept 6.5. Started doing it on about day 3 of it's refurb, just as we were putting the final cosmetic parts back on. We should have thought of it before as now we're stripping the front back down. Oh well, better now than later)
 
 

 

Issue: Turning the stereo tuner knob does not move tuning dial pointer consistently or proportionally.

A: The tuning string is slipping on the flywheel shaft. The string may need to be ‘cleaned’ and re-tensioned, or ultimately replaced. We have had ‘limited’ success increasing ‘traction’ with a small amount of violin bow rosin applied to the string after cleaning. This however can lead to ‘string overlapping’ (see next issue).

 

 

Issue: My tuner / radio knob spins / turns for a few turns,  then ‘locks-up’ and stops before dial pointer gets very far or to end of dial.

     A: This is usually due to the tuning string ‘jumping or climbing over’ / ‘overlapping’ on one of the winds on the tuning flywheel shaft (there are typically 3) and getting ‘caught’ by a previous winding. This is a ‘PITA’ issue and we don’t have a ‘tried and tru’ fix for it short of the above mentioned steps or replacement of the string or ‘bad section’ of string. This is can be a difficult issue to resolve.
 



Issue: My ‘digital’ tuner does not hold memory or is erratic or has ‘weird’ symbols in the display.

     A: Some tuners use a ‘back up battery’ to retain the station memory. The battery may even be necessary to the proper function of the tuner.  The tuner ’back up battery’ is likely bad and will need to be replaced. These are commonly soldered in and may require a qualified electronics technician to repair, not to mention a 'special battery' to either be ordered or made.



TURNTABLE / RECORD PLAYER / PHONOGRAPH ISSUES:


Issue: My Turntable / record player ‘howls’ / rumbles when I play it, especially when I try and turn the volume up.

     A: This is caused by ‘feedback’ between the speakers and the tone arm 'pickup cartridge'. The record / platter / tone-arm combination is resonating sympathetically to the sound emanating from the speakers. The closer the turntable is to the speakers, the more of an issue it may be. I’ve actually seen folks set the turntable directly on a speaker. That will result in almost instant feedback, even at low volumes. Some stereo cabinet / turntable combinations will ‘amplify’ feedback due to their natural tendency to resonate. Some ‘cheap’ turntables are in housings, especially the cheaper plastic type, that tend to ‘ring’ and encourage feedback. You may need to experiment with different turntable placement / locations. A good solution may be to mount the turntable and / or speakers on good isolation feet. We have our turntable sitting on Sorbathane isolation ‘hemispheres’ (and it’s a Kenwood KD-550 ‘Concrete’ base turntable), but unfortunately the cabinet I have it in is very resonate and encourages feedback. The Sorbothane ‘fixed’ it. Here’s a link to our ‘Sorbothane Page’: http://www.oaktreevintage.com/Isolation_Feet.htm  


Issue: My Turntable / record player ‘hums’ / 'buzzes', even when it's not spinning...

     A: This is a common issue, and is usually proactively addressed by the turntable manufacturer by adding a 'ground wire' which should be connected to the Gnd lug on the back of your receiver / amplifier. Some turntables will not have a ground wire. In this case, you could try 'reversing / inverting' the AC plug in the AC outlet. This will sometimes reduce the 60Hz hum / buzz. You will likely always have some hum / buzz if you turn the volume up enough on your amp / receiver, even if the grounding system is correct. This can sometimes be reduced further by adding / modifying grounds, but that is beyond the scope of what can be covered here.
     Or, consider an issue we had with a recent turntable. We had a BSR table with a 'magnetic' cartridge installed. We were getting a fairly 'sharp' sounding 60Hz buzz. "Sharp" meaning that it wasn't just a 'hum', but had a 'treble' component to it which made it have more of a 60Hz 'click', that also seemed to be intermittent, would be more prominent on one channel for a while, then would be on both channels. This particular model, BSR Chassis model #185, had 'de-tachable' RCA cables, and a removable 'sled' / carriage for the cartridge to mount to the headshell. He replaced the RCA patch cables, and of course burnished and 're-sprung' the contacts for the cartridge carrier as part of the original restoration. We discovered the 'excess' hum / buzz while I was auditioning it for final inspection / signoff. On my 'test receiver' I noticed the excess 60HZ buzz. We tried inverting the AC cord (which of course had no effect as the motor wasn't spinning, but you start with the easiest / simplest stuff first). We swapped RCA cable channels, but buzz still persisted intermittently left to right. Then he revisited the cartridge carrier contacts, still to no avail. Then he replaced the cartridge with a new one, still to no avail. I noticed some 'intermittency' with the input selector on my receiver, and thought maybe that was causing it. I had another receiver handy to try, however a receiver swap did not address it. Then I thought to install another set of RCA patch cables / interlinks. I didn't suggest this first, as I assumed they were soldered in place, and would take an inordinate amount of time (relative to other procedures) to change. He then informed me that they were 'removable'. He had installed standard, inexpensive RCA's. Most of our better turntable restorations / refurbs include upgrading the RCA patch cables / interlinks as a matter of course, but again this was a BSR. He had actually tried that, but the RCA jacks on the BSR are very close to each other (like on some vintage Pioneer receivers BTW) so that's why he chose the entry level / $5-8 cables, as they have 'thinner' plug housings. We tried a number of upgraded RCA cables, until we found a set we could 'just get to fit' side by side. Once we turned everything on, 'viola'...problem solved. As I've always said a $10,000-$50,000 audio system can be brought down by a $3 cable.




Issue: My Turntable speed adjustment ‘knobs’ are erratic and won’t hold the platter at a steady speed.

     A: The speed potentiometers / controls need to be cleaned internally.


Issue: I've connected my turntable to my receiver / amp, but can barely hear any sound. It's low and not very clear...

     A: There are a few potential causes that come to mind and we're going to assume a 'magnetic cartridge' is being used.
           1) Did you connect to a proper "Phono" input? Most vintage / quality receivers / integrated amplifiers will have a phono pre-amp built-in, and without that, most turntables will not deliver much if any sound. If you don't have a proper "Phono" input, you can add one, then use any 'analog' input (AUX, Tape, CD, Video, etc). While pre-amps can cost $5,000.00 or more, a $30-$50. one will be adequate for most folks.
           2) Are you trying to connect a turntable with a 'Moving Coil / MC' cartridge to a 'normal' phono input designed for a "MM / Moving Magnet" cartridge. You'll need a "Moving Coil 'Head Amp' " as the MC cartridge has a MUCH lower output than a MM cartridge.
           3) Are your patch cables good?
           4) There could be an issue with the Phono Pre-Amp or some part of that circuit in the receiver / amp. (beyond the scope of this writing and would need to be addressed by a qualified tech, or again, simply purchase an external pre-amp and connect to another input)
           5) There could be an issue with the turntable, ie; Bad tone-arm wires, compromised internal connections, loose fitting headshell connections etc. (beyond the scope of this writing and would need to be addressed by a qualified tech)
           6) There could be an issue with the cartridge / stylus, ie; bad internal coils, internal magnets broken off or 'de-gaused', too many 'dust bunnies' inside, or
broken or sheared off stylus or bent cantilever. Replace the cartridge or stylus or preferably the complete cartridge / stylus combo. The problem can also be due to a severely mal-adjusted, ‘Anti-Skating’ coupled with much too light of a tracking force. If the issue cannot be attributed to a stylus problem, then re-adjust the ‘Anti-Skate’ and tone arm tracking force. Here is a link to our page of NEW TURNTABLE CARTRIDGES / NEEDLE combinations: http://www.oaktreevintage.com/Turntable_Cartridges.htm
 (revised 2019)


Issue: My turntable speed controls won’t turn far enough to get the strobe / speed correct. I've turned it all the way and it's still too slow / fast.

     A: Most turntables have ‘first stage’, internally located, speed potentiometers (sometimes erroneously referred to as a 'rheostat', which is a different kind of 'attenuation' control, usually used for larger amounts of current, than a 'variable resistor / potentiometer') that likely need to be adjusted (and cleaned as well). There may be ‘access ports’ on the bottom plate for adjustment, that may or may not be marked. They are not something that needs to be accessed / adjusted by the user typically. Sometimes the bottom plate must be removed to access them. The bottom plate would need to be removed to properly clean them anyway. This is not a particularly easy task to do either way, as it requires adjustment under the table, while it is running. Probably a repair best left to a qualified electronics technician. (revised 2018)




Issue: My turntable tone-arm drops too fast and 'bounces the needle' or way too slow, or the tone-arm won't move up or down at all...

     A: Most turntable tone-arms are ‘damped’ by a silicone fluid and sometimes this can leak out. This will cause the tone-arm to drop too fast. If the tone arm is dropping way too slow, then the original silicone damping fluid / oil has become too viscous or has foreign matter contaminating it. Either way, the silicone damping fluid / oil likely needs to be replaced with fresh, probably 500,000 grade silicone oil / fluid / gel (maybe 300,000 grade silicone damping fluid, or a mixture of the two). To replace it, the tone arm cuing mechanism will need to be disassembled, cleaned and then have the silicone gel replaced. If it is prone to leak, it will likely take 20-30 years to leak out, so probably not worth addressing the 'future leak’ aspects. We see ‘leaked out silicone cuing gel’ commonly on turntables such as the Pioneer PL-40, PL-41, PL-50, PL-51 & PL-61. (revised 2018)


Issue: My Pioneer PL-40, PL-41, PL-50, PL-51 or PL-61 turntable runs slow, slows down, takes a long time to come up to speed, won't turn well in cold temperatures...

     A: We have learned that the platter motor on this series of Pioneer turntable, has to be disassembled and have the bushings / bearings cleaned typically 2-3 times. Once cleaned THOROUGHLY, then re-lubed. Also, the 'CORRECT' belt is fairly 'rare' and needs to be tested for correct speed once replaced (I see lots of replacements there that aren't correct). We usually have to try a few on each table with a 'strobe disc' to get a correct one for each table (All are 'long' (by normal standards) and the most correct one can range from 30.0" to 35.1").
(revised 2018)


Issue: My Pioneer PL-40, PL-41, PL-50, PL-51 or PL-61 doesn't 'Auto-Return' the tone-arm very consistently or not at all...

     A: The 'return' mechanism for the tone arm on this series is fairly 'un-orthodox', but once restored (or at least verified to be functioning correctly) does work well. It's 'restoration / refurbishment' is a 'massive undertaking' and very complicated to get returned to correct function. Also requires 300,000-500,000 grade silicone gel.


Issue: My turntable doesn’t ‘start’ automatically, or the platter won’t start turning or very little of the 'Auto' functions operate correctly, or at all...

     A: Most issues regarding a turntable ‘not running’ or not ‘auto-starting’ in the case of a ‘Fully-Automatic’ turntable, can be attributed to gummy / varnished lubes,    with the exception of an issue due to a worn / stretched ‘belt drive’ or ‘idler drive’ table, and then we would additionally look at the rubber belt condition or that of the rubber idler drive tire. Besides replacing the belt and reconditioning any rubber drive wheels / tires, disassembly, cleaning and re-lubing EVERYTHING is in order. The platter spindle is the first thing to disassemble, clean and re-lube (almost every BIC turntable will have a 'stuck' platter, ie; BIC 940, BIC 960 & BIC 980 to name a few). If the turntable is ‘belt drive’, then the motor spindle needs to be checked for ‘free-running’ condition and cleaned and re-lubed as necessary. If a belt has ‘melted’ around the motor pulley / spindle, then that could be impeding its motion and will need to be addressed accordingly. In the case of an ‘automatic’ table, any moving parts associated with the mechanized movement of the tone-arm will need the same treatment. Some tone-arms are driven by a motor / belt and that may need to be serviced. If it's on a linear tracking turntable, the tone-arm will almost assuredly be driven by a separated motor / belt and if the belt is broken or stretched the tone-arm will not move, thus the platter may not start. Also the tone arm moves along a rod that should be lubricated, typically with silicone damping fluid / oil in the 300,000 to 500,000 grade.
     We recently restored a Technics SL-1950, DD, Fully-Automatic turntable. Great table once we restored it, but that required completely disassembling every internal part of the mechanism (probably 50+ parts), cleaning them in lacquer thinner, re-lubing each part with correct type of lube, and reassembling. This operation is similar to taking your dad's pocket watch apart, but it must be done for the table to function.


Issue: The needle (tone) arm on my Montgomery Wards (insert; BSR, Magnavox, Pennys, Sears, Zenith, or any other brand  (changer / stacker) turntable, picks up, goes across to the end of the album never and sets down, then returning to the arm rest. I can stop it manually and sit the needle on the record and it will play. Any suggestions...

     A: Most issues with 40-50+ year old turntables, especially any with automatic features / functions (and a changer / stacker has the most 'auto functions') will be attributed to 'varnished / gelled' lubricants. There is likely a mechanism that is stuck, and not 'catching' something that it should on the way to the beginning of the record. I'm surprised you get any function out of it. The best solution is to have a qualified tech type person, clean and relube ALL mechanisms (meaning any and every moving part needs to be disassembled, cleaned and relubed with an appropriated lubricant (oil or grease)). As long as that degree of work is being done, any / all rubber parts should be reconditioned as well. This is pretty much a 'restoration', and not any easy task, and not for everyone.


Issue: The tone arm on my record player / turntable just skids / skips across the record.

     A: This is usually the sign of a broken or sheared off stylus or bent cantilever. Replace the stylus or preferably the complete cartridge / stylus combo. The problem can also be due to a severely mal-adjusted, ‘Anti-Skating’ coupled with much too light of a tracking force. If the issue cannot be attributed to a stylus problem, then re-adjust the ‘Anti-Skate’ and tone arm tracking force. Here is a link to our page of NEW TURNTABLE CARTRIDGES / NEEDLE combinations: http://www.oaktreevintage.com/Turntable_Cartridges.htm




Issue: The tone arm / needle won’t go all the way to end of a record.

     A: There are a couple of causes for this. The motion may be impeded by the counterweight being ‘too far forward’ and partially touching the ‘gimbal’ bearing mechanism. Assuming it is the correct counter weight for the turntable / tone arm, then use lighter head shell / cartridge combination (you could also potentially add a bit of ‘mass’ to the rear of the tone-arm, then re-balance the tone-arm, but you’re on your own there. Maybe try some lead tape (get it at a ‘Golf Pro Shop’. Harbor Freight sells 'stick on' wheel weights that work as well). Another reason for the movement of a tone-arm being impeded could be gelled / varnished lubricants, but we rarely see that as an issue in a tone-arm Gimbal bearing assembly. There further could be an issue with the pivot pins / points in the tone-arm Gimbal bearing assembly. We have seen that, but it’s typically on the ‘cheaper’ turntables, with a lot of ‘plastic’ parts. We rarely see it on ‘quality’ turntables.
(revised 2018)



Issue: My tone arm / needle doesn’t start or end at correct place on the record, or it ‘sets down off the edge of the record’.

     A: Barring issues again, with ‘gelled / varnished’ lubricants, this is usually a ‘Lead In / Lead Out’ adjustment issue. This can typically be adjusted. On some turntables, there is a small port / hole near the tone-arm bearing assembly to allow access to the adjustment. This hole is usually covered with a small rubber plug. On some tables, you must go underneath the table, or worse yet, disassemble the table, or remove the platter to get to the adjustment (a really stupid design). Some tables require some part of the mechanism to be ‘bent’ to make the adjustment (again, a really stupid design). Regardless of how the adjustment takes place, typically ‘a little goes a long way’ when you’re making the adjustment. Usually, you are adjusting the ‘Lead-In’ and the ‘Lead-Out’ will be 'relative'.
(revised 2018)



Issue: Help, the entire ‘end’ of my tone-arm is missing...

     A: Well, which end do you mean? If you mean the ‘back end’ where the counter weight is (was), then that is bad, and may not be practical to ‘chase’ a solution for. This usually is damage inflicted by not removing the counterweight, prior to packing for shipment.
     If you mean the ‘front end’, then that’s not necessarily a ‘big deal’. If your turntable utilizes a ‘universal’ type head shell, then those are readily available. The sign your table uses a ‘universal’ type head shell, is that the tone arm will have a slight ‘S’ or ‘J’ curve to it.
     If it has a ‘straight’ tone arm and is missing the headshell, then you will usually need to source a correct one (usually matching the ‘brand’ is sufficient). Once a head shell is obtained, then a cartridge can be installed.




Issue: The platter on my 'belt drive' turntable doesn't start / move...

     A: The first and primary reason that the platter on a 'belt drive' turntable doesn't move / turn is because there's an issue with the belt. It's likely either severely stretched, broken, 'tracked off' it's correct position, missing, or turned to 'goo'. Belt issues can usually be deduced by removing the platter (usually just 'lifts' off on a belt drive turntable {may need to give the spindle a slight 'tap' with something hard, while pulling up on the platter to get it to release}). If there's an issue with the belt, determine that the motor runs while you're in there. Simply try and start the turntable, with the platter removed, and check the motor spindle / pulley for rotation. If it's not spinning, then you likely have a more serious issue. If the motor is spinning, then address the belt.




Issue: The belt (or at least what I think was the belt) has melted and turned to 'goo' under the platter of my turntable...

     A: Yes, that happens to the rubber in many units, including turntables, tape decks of all types, VCR's, Film Projectors and just about anything with rubber parts over 25 years old. The belt was reverting back to it's natural state, a 'gooey / tar-like' substance. You will need to get all the old 'tarry rubber' off of everything with a proper solvent before installing a new belt / rubber part.


Issue: I have a 'Linear Tracking / Tangential Tracking' turntable (such as Technics SL-5, SL-6, SL-10 etc) and the arm won't move laterally (across the record)...

     A: There could be a few reasons for that. There's a belt that connects a computer controlled / servo motor to the tone arm mechanism. That belt likely needs to be replaced due to deterioration of the rubber, or it's 'stiffened' into one shape, or broken / stretched etc. ...
     Or the high viscosity silicon gel / lube on the tube that the tone arm moves across on is missing, insufficient, dirty (it 'holds' any debris such as dirt / dust / hair / fuzz etc that comes into contact with it) or has 'hardened' to the point as to impede the tone arm carriers motion and needs to be completely / thoroughly cleaned and replaced...
     Or there's an issue with the circuit that controls the motion or an issue with the motor...
     Or some of the 30+ year old nylon / plastic parts have broken in such a way as to block or bind up the mechanism...
     Or .....
     Regardless of the cause, they're generally no 'user repairable / addressable' issues and will likely need a visit to a qualified technician familiar with working on linear tracking turntables.
(revised 2019)



Issue: I have a BIC turntable and the platter is stuck / doesn't move / is very stiff, etc...

     A: BIC TURNTABLE ISSUES. Wow, where do we start. Yes, we know the common issue is a ‘frozen’ or stuck platter due to hardened / gelled / varnished lubes, but in our opinion the BIC 940, 960 & 980 have multiple basic ‘design’ issues (at least from a standpoint of trying to resurrect them 40 years later). Sorry, but we’ve essentially ‘written off’ restoring anymore of those units. They’ve cost us too much in time and money resources, so now they're on our 'no fly list'.

Issue: I have a 'Stacker / changer' turntable and sometimes the records 'hang up' and won't drop, or sometimes it drops 2 at a time...

     A: Yes, that's correct. Sometimes they will do one or both. Even a properly serviced / restored changer will do one or both of those things. The "Changer / Stacker" functions will generally work best when used with pre 1980's albums due to the larger center hole diameter of older records. They also can sometimes work with up to 4 or 5 albums and even 6 on some table / record combinations, but generally function best with 3 or less stacked at a time. Occasionally a 'stacker / changer' will either 'not drop' a record, or may drop more than one at a time. The physics of the mechanism / record hold size and internal shape will be different on various records, and it's not, nor never was a 'fine science'. Having said that, stacked records will 'drop and play' in order, just fine, the majority of the time on a fully serviced / properly refurbished record changer / stacker. Now we have to assume that you are experiencing those symptoms on a properly serviced / fully refurbished 'stacker / changer' table. If not, then it would need to be completely serviced / refurbished before you can deduce 'detailed issues' with the changer / stacker mechanism.
(revised 2018)


MISC HINTS / ISSUES:


Issue: My audio timer doesn’t keep time well, or ‘jumps ahead hours’, or is simply erratic...

     A: Audio timers use a ‘memory battery / capacitor’ internally, and after 25+ years, this will undoubtedly be ‘on it’s last legs’ and if the unit still functions at all, it’s battery is ‘running on vapors’. The solution is to replace the battery. While the batteries are available from some electronics parts sources (such as MCM Electronics) this is typically a job best left to a qualified technician.

 

Issue: I need replacement lamps / bulbs for the dial on my Stereo / radio. Do you have them, and / or what voltage they are?...

     A: At this time we do not sell replacement lamps / bulbs. We generally have to test each unit we are restoring on the bench to determine which lamp / bulb to re-install in each position (as exact originals may no longer be made, or impractical to source). We get most of our bulbs / lamps from: www.mcminone.com  , www.partsexpress.com , www.tubesandmore.com , www.vintage-electronics.net , Radio Shack, and a few other sources including some ‘real’ electronics parts shops close to us. If you contact most of the places, with the exception of www.vintage-electronics.net  and say, “I need a lamp / bulb for an XXX brand, XXX model unit”, they are not going to have a clue what lamps you need. You will need to figure that out by ‘lamp’ number or original lamp / bulb catalog number. Better yet, turn the unit over to a qualified technician to do the ordering and make the changes.
     People that sell ‘Bulb kits’ / ‘lamp kits’ have likely deduced all the light bulbs / lamps that a unit needs by actually going through each unit and making notes as part of a restoration, (or possibly going through a service manual) then sourcing all the correct, or closest to correct lamps and putting those parts together as a kit. It’s actually a difficult process to come up with all the correct lights in most stereo receivers, especially on the larger, more complex models.



Issue: How do I connect an Equalizer, reverb, or dynamic range expander to my system?...

     A: Generally the best way is to utilize a SEPARATE ‘Tape Monitor Loop’. Most ‘old-school’, ‘2-channel’ receivers, integrated amplifiers, and pre-amps have a separate tape monitor. You connect the ‘Tape Record’ on the receiver / pre-amp to the EQ ‘Input’ and the ‘Tape Play’ on the receiver to the EQ ‘Output’.
     A second best, less desirable way, is to ‘insert’ the EQ or other signal processor into the Pre-Post loop, usually marked “Pre-Out” and “Main / Power-In” or similar (most lower to ‘mid’ priced units will not offer this feature). This is a less desirable point as you are changing your ‘Signal to Noise’ ratio every time you adjust the ‘volume’ control on your receiver / pre-amp, but it’s typically, excusably negligible.
    
The third and least versatile way to do it, although sonically fine, is to relegate the EQ to only one ‘external’ source, such as a CD player, DVD player, MP3 player, Tape Deck or other ‘line-level’ device. Unless you have a separate tuner, you could not use it on the AM/FM of a receiver. Also, unless you were utilized an ‘outboard’ phono pre-amp, you couldn’t use it in this manner on a turntable.
(How do I know if I have a ‘Separate Tape Monitor’. If the ‘tape monitor(s)’ is a switch, separate from the rest of the ‘Input/ Source’ selectors, ie; AM/FM, AUX, PHONO, and / or when you engage the tape monitor, and it doesn’t ‘cancel’ out the AM/FM, AUX, PHONO, then you have a separate tape monitor loop. Prior to about 1983 or 84, it’s almost a ‘given’ that units will have separate tape monitors. After that, sometimes, the tape monitor was combined with the other inputs and won’t work with an EQ or any other signal processor.)




Issue: If I have a service manual or schematic, I can fix my unit….Right.?

     A: Not necessarily nor likely. A service manual and certainly a schematic is not usually a ‘how to’ manual, but will typically be only a basic, and usually ‘technically written’ ‘guide’ for a trained and experienced electronics service / bench repair technician to ‘decipher’.




Issue: I am out of inputs on my receiver / integrated amplifier. The only one available is the ‘Phono’ and I’m not using a turntable, so don’t need it, but I know you can’t plug anything into that...

     A: There are a couple of ways to tackle that. You could purchase an external ‘Tape Monitor switch / input selector and expand one of the other inputs. There are many different versions of those out there. The other option, if you really only need ‘one more’ input is to purchase a ‘Reverse Phono Pre-Amp’. It is a small ‘box’ that you put in between the ‘line level’ device you wish to connect and the phono input. It attenuates down the ‘line level’ device such as a DVD player or an MP3 player from 100-150 mV to approx 5mV. It also reverses the RIAA equalization, built into the phono pre-amp. We use them in the shop all the time to test the ‘phono’ inputs of receivers / pre-amps with CD players (as it’s not practical to have a turntable on the work bench typically, and certainly more convenient).

 


Issue: My old, antique, tube radio hums even after it warms up...

    
A: This is usually more of an issue on antique / vintage ‘Tube Type’ radios that are over 40+ years old. It’s generally caused by ‘dried-up’ power supply filter caps (capacitors). Anytime we restore a ‘vintage’ or antique tube radio or tube amp, it’s a ‘given’ that we will replace the filter capacitors with fresh parts.
If you don’t know what any of this is referring to, or have never done ‘tube work’, THEN DON’T!!! Most tube electronics operate with voltages of 300-600 VOLTS!!! Also, capacitors can store a potentially lethal charge for many years after its’ last use, even if it’s not plugged in, and even if it hasn’t been plugged in for years! If you’re qualified to work on ‘tube electronics’, then a great source for replacement capacitors, tubes, knobs, tuning string, pilot / dial lamps, restoration books, and most other needed supplies is ‘Antique Electronic Supply’, www.tubesandmore.com  
 


Issue: When I connect my "iDevice's" (smart phone, satellite radio, portable 'whatever')  'headphone output' to my receiver (amp), the sound has excessive distortion in it...

    
A: So "excessive" can be in the "eye of the beholder", but lets assume you mean by 'reasonable standards'. The "headphone output" is not the best way to connect, but for many folks and situations, it's probably the 'default' method (hey, I've done it too in a pinch). If you are going to do that, you need to realize that "iDevice's" the built-in, headphone amplifier may be capable of much higher level than typical 'Line Level' devices, thus you'll want to reduce the volume on the 'iDevice' (you probably had it fairly high to drive your headphones) to a level that sounds good without distortion. Be aware that if you lower it too much, you may introduce 'hiss' (electronic noise that you may or may not notice) thus lowering your 'signal to noise' ratio. A proper 'docking station' with a proper line output (typically in the 150mV range) would likely be a better option (don't use the 'headphone output' on the docking station as you'll have the same issue). (revised 2019)


Issue: North American Voltage unit being used in Europe / Asia or visa-versa...

     Recent email regarding a unit designed for the North American market, being sold to someone in Europe:
"My name's Dim. Music lover, Belgian sound engineer, with a big trouble...I love your shop and your website, and according to me you simply are the bests on...I spend hours by reading what you do, and all those crazy old audio stuffs you've just bring alive! Anyway...The reason I'm contacting you is simple. I've just bought a great PIONEER TX-9100 tuner, on ebay...Want to make it working, but when I try to put it on, nothing happens...The unit is (I guess) an US version, because of its plug (2 flat parts with holes on it). It is written: 120 volts, 30 watts, AC 60 Hz, with a "FUSE AC lines 1A-125V" on back panel, and a "AC outlet un-switched 500W max" output as well...Here in Belgium, we use regular 2 pins European plugs...I kwew when I bought it that I had to put an adapter at the end of the plug, to make it compliant on European voltage plugs. That's what I did, but it wasn't that easy so because the unit doesn't seems to work at all...No light, no sound, nothing!... Should I change the general US plug, and put an European one? Should I buy a special chord for the AC un-switched outled, to make it work in Europe?
Many thanks to you in advance, and if you need additional informations on my unit, just let me know! Dimitri"

"Hi Dimitri,
Thanks for visiting oaktreevintage.com.
The TX-9100 'can' be a great tuner, as long as it has a 'clean bill of health' from a qualified tech.
Having said that, none of that matters if you don't have the correct power for it, and from what you've told me, you don't. They did make units that were 'multi-voltage / multi-Hz' but doesn't sound like this is one of them. The only advice I can offer is that you need to supply it with 60Hz / 120V AC power / current / voltage. They do make transformers to convert 220/240 V to 110/120V, but they are generally designed for use with appliances and not delicate electronics. They do make them of that quality, but they are expensive. Secondly you need to address the Hz. Running a 60Hz unit on 50Hz might be ok, or it might not, or it might be ok for a while, but on a tuner the power supply circuit is what would be of concern. DO NOT SIMPLY PUT ON AN ADAPTOR PLUG THAT ONLY ADDRESS 'PIN / PLUG FIT'.
Assuming no damage has been done (yet), don't risk further damage without a COMPLETE understanding of how to get this unit powered up safely with the correct transformer designed for 'delicate electronics' and really the Hz issue should be addressed to, but that can be VERY EXPENSIVE. Hope that info helps.
Keep checking as we never know from day to day what will arrive. Good luck and thanks again,
Jerry at  www.oaktreevintage.com  


ANOTHER OF SIMILAR ISSUE...
"Ciao, it's Dante from Italy, I need deeply some help, would be kind of You if could help me with some troubles on my Audiotronics 312T classroom turntable...
it seems that every speed is going slow....checked the other "twin" model I have and everything is total the same as the on the other one.
So I would like to know if on the motor there is a "kind" of screw or something else to regulate speed and pitch....
I would be glad to have some help and enjoy the Audiotronics with some records, Thank You in advance, Dante
"

"Hi Dante , Thanks for visiting oaktreevintage.com. All of those 'vintage / older' 'classroom' type phonographs (including Audiotronics) are 'rim drive'.
Very simple motor with a 'stepped' capstan that drives a rubber wheel that gets 'wedged' between the motor capstan and the inside of the platter rim.
The motor speed is controlled ONLY by the 'HZ' of the AC motor. There is no "speed control" inside on these types of phonographs.
There are 3 likely causes for those symptoms. If you do not have a turntable / phonograph designed for European / 50Hz AC current, then you would need to address that.
There are a few ways to address, but all of them will be either 'expensive' and or difficult to do at best. If that is the case, I would 'start over' and find a unit that is already designed for your AC current.
If your unit is designed for '50Hz' current, then the
cause is likely either the motor is 'gummy' and needs to be cleaned and re-lubed (as well as the 'idler wheel' bushing),
and / or the rubber drive wheel is hardened and slick and needs to be re-surfaced or replaced.
Both issues could be causing the speed slowness as well. Hope that helps. Good luck and thanks again, Jerry"




Issue: When I 'touch' the face / knob / case of my stereo receiver / amp / unit, I get a slight electrical shock or tingle, especially if I touch it with my bare arm...

     A: This is usually not much of a problem on more modern gear (although 'modern' gear generally has many more design / quality issues than more 'vintage' gear) as the wall plugs on the AC cord tends to be 'polarized', meaning it will only fit into the wall outlet 'one way' (one of the spades / terminals on the plug is wider (the 'neutral' one)). On most older gear, and on gear with 'round' pins such as European / Asian gear, the plug can be inserted into the wall outlet either way. Normally this doesn't present any issues, however, occasionally, either due to original design, or a problem a unit may have developed, voltage can be present if the plug is 'inverted' (ie, the 'neutral / skinny' spade is in the 'hot' connector). There are two ways to approach this. The safest is to have a technician take a look at the unit to ensure there is not a problem that has developed. The second, and the technician may default to this either by instructing you to do it, or by installing a 'polarized' plug, or even going further by retrofitting a 'grounded / 3-Prong' plug, is to have you simply 'invert' the plug in the outlet. AGAIN, the safest route is to have the unit checked for overall safety prior to simply inverting the plug. There could be an underlying issue, that could be potentially 'fatal' TO THE USER, aside from the gear.
(revised 2018)




Issue: "I just purchased a Pioneer RT-909 from a fleeeeeeeeeebay seller. Besides the rollers and the belt what else would be suggested to change in a “tune-up” of a Pioneer RT-909? Would you carry replacement plastic legs? Regards, Frank...

     A: Hi Frank,
     Thanks for visiting oaktreevintage.com. So the 909 has proven to be a fairly durable design with not too much to need to address (other than the belt and rollers of course). The tension arms tend to get sluggish as does the pinch roller ‘lift mechanism’. One or both of those need to be addressed currently on about 50% of the units out there by disassembling, cleaning out old ‘stiff’ lube and re-lubing. Also as the ‘reel motors’ are “AC” powered, they require ‘start / run’ capacitors to function and we get quite a few calls for replacements as their 40 years old now (should really be replaced with ‘fresh / new’ ones though and not our 'take-outs'). Probably the biggest (most expensive and difficult to find) part we get requests for would be the capstan motor. The spaces between the commutators become filled with carbon which causes issues with the motor. This can sometimes be cleaned out and the motor revitalized, but it was never meant to be taken apart, so is not only tricky, but risky to the motor (but kind of falls under the heading of, “what have you got to loose”). The parts I get the most requests for and sell almost instantly would be the ‘spindle tips’, and the ‘black skids / feet’ as they are often broken in transit / shipping due to inadequate packing usually by inexperienced fleeeeeeeeeeeeeeebay sellers that probably shouldn’t be selling reel to reels.

Yes, we have quite a few parts, shown on our ‘Pioneer RT-901/909 Parts’ page.
Here's a direct link to our “Pioneer RT-901/909 Parts’ page that shows those:

http://www.oaktreevintage.com/Pioneer_RT-909_Parts.htm 

and of course we also have the rubber kit;

http://www.oaktreevintage.com/Pioneer_RT-909_Pinch_Rollers.htm 

Issue: Parts no longer available; "I’ve got a surround sound amp and everything still works on it EXCEPT the motorized volume control no longer works by remote control (The remotes are good, yes, there are two) but apparently, the little motor could – can’t do it anymore.  Now the parts outlet for this brand / model says the part is no longer made and they don’t have an alternative. Any thoughts on the matter ??" Steve

     A: "Thanks for visiting www.oaktreevintage.com . Unfortunately that is a unit we’ve never had come in (yet) to be parted out. Sorry.
    
So as far as “thoughts”. Pretty much the only way you’re going to find parts for units over 7+ years old (almost regardless of the industry), is you’ll need to get it from another of like / kind unit. We have to do that all the time. There may be other models that use the same part, which would be useful to know so that you can widen the scope of potential donor units in your search. It’s a bit tedious to figure that info out, but what you have to first do is figure out what other units from the model year yours was made. A ‘web search’ might give you the info, but that info may or may not be accurate, nor complete (may have to look at a resource such as “Usedprice.com”, which is the web site for Orion Blue Book. Historically they try and list all units, by all mfgs, by years). Then once you have model numbers, start sourcing / downloading / collecting service manuals for not only your unit, but the ‘flanking’ models to yours. Then search the service manuals for part numbers. Again, it’s potentially a ‘LOT’ of leg work, but typically better you do it than paying a tech ‘shop hourly rate’ to do it. Sometimes you won’t get anywhere doing all that (for various reasons), but that’s part of the risk. Once you determine which unit(s) utilize that same part number, then you can expand your search to those models. Ultimately you may have to purchase an entire unit simply to get the part(s) you need. You’ll need to determine if a unit is worth the above effort / resources which could be based on a multitude of factors. I hope this helps."
 

RELATED ISSUE FOR MUSICIANS

Issue: When I my guitar / bass, then go up to a microphone, or sit on a 'metal' stool / chair, I get an electrical shock or tingle, especially on my lips...

     A: Put's a whole new meaning to the name 'Hot Lips'...(Yes, I know, BOO-HISS, but it had to be said).  Anyway, this is usually not a common problem on more modern gear (although 'modern' gear generally has many more design / quality issues and problems than more 'vintage' gear) as the wall plugs on the AC cord tends to be grounded with 3-prong plugs or at least 'polarized', meaning it will only fit into the wall outlet 'one way' (one of the spades / terminals on the plug is wider (the 'neutral' one)). On most older gear (tube guitar amps, tube PA heads, etc) and on gear with 'round' pins such as European / Asian gear, the plug can be inserted into the wall outlet either way. (I have had this happen MANY times myself). You are holding your bass / guitar and walk up to a 'metal-screened' microphone, such as the famous and widespread Shure SM-58, touch your lips to it, and get the s*#t knocked out of you. Or you're standing on a basement concrete floor, barefooted (probably a bad idea in the first place...get some shoes), and either grab your guitar or bass, or a microphone and ditto, electric shock. This shock can typically have a full 120V (if in North America) or 220-240 volts if in Europe / Asia. The sever-ness of the shock is dictated by aspects such as the humidity of the air, floor, your skin ambient humidity (how sweaty you are), the finish on the mic, how much 'dirt / grime' is coating your guitar strings, etc. This shock can be potentially very painful. I've not personally heard of anyone getting a fatal shock this way, but it's probably happened and I'm sure someone will contact me with a 'story'. Normally this is either due to original design, or a problem a unit may have developed, voltage can be present if the plug is 'inverted' (ie, the 'neutral / skinny' spade is in the 'hot' connector). There are three ways to approach this. The safest (and probably best) is to have a technician take a look at the unit to ensure there is not a problem that has developed. The second is to check the 'GND' switch on any related guitar / bass / instrument amps, if applicable. If it has a 'GND' switch, then flip it to the other position and see if the shock potential is still there (safest way is with a 'volt meter', which every musician (involved with electrical related instruments) / roadie / soundman should own already). Sometimes on older 'tube' guitar amps, the power switch will have 3-positions (1x Off and 2x On) that allows it to double as a neutral / hot inversion switch. If so, try the other 'power switch' position. The third, and the technician may default to this either by instructing you to do it, or by installing a 'polarized' plug, or even going further by retrofitting a 'grounded / 3-Prong' plug, is to have you simply 'invert' the plug in the outlet. AGAIN, the safest route is to have the unit checked for overall safety prior to simply inverting the plug. There could be an underlying issue, that could be potentially 'fatal' TO THE USER, aside from the gear.
 

MORE TO FOLLOW AS TIME ALLOWS......


Due to limited resources we are only able to do restorations / repairs on OUR OWN inventory and unable to take OUTSIDE / CUSTOMER repairs.
If you need work done to your gear,



TRY         SOME         OF         THESE         RESOURCES


 

-WARNING: PLEASE USE CAUTION WITH ANY ELECTRICAL DEVICE. ANY REPAIR AND / OR

-RESTORATION SHOULD BE UNDERTAKEN ONLY BY A QUALIFIED TECHNICIAN. THE TEXT'S BELOW

ARE NOT INSTRUCTIONS FOR DOING YOUR OWN REPAIR AND ARE NOT COMPREHENSIVE IN SCOPE.
 



 

 

 

 

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Due to limited resources we are only able to do restorations / repairs on OUR OWN inventory and unable to take OUTSIDE / CUSTOMER repairs.
If you need work done to your gear,
TRY SOME OF THESE RESOURCES