Categories

Home
Hi-Fi / Stereo Gear
Speakers
Receivers
Tuners
Amps / Pre-Amps
EQs / Signal Procs
Cassette Decks
Reel - Reel Decks
Turntables
Cartridges
8 Track Players
Headphones
Speaker Parts
Stereo Parts
HI-Fi Accessories

Customer Care

Contact Us
Repair Resources
Restoration Steps
 

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. 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, 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.
 

 

 



 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



 

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."

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 station that would be willing to take a look.
 

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 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, they 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’.  If fact probably the only place you’re going to find a suitable replacement is from a salvage / donor unit (unless you don’t care about the originality of the unit, exact performance, exact look etc, then hey, you could probably make ‘spit, some old carpet lint and duct tape’ work). 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 correct 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 too much speaker load for the volume you are trying to achieve (similar issue addressed above).
     Solution; Either use less speakers, or lower 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: 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 power 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).

An alternative email we received; I have a older pioneer stereo reciver sx- 9800 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 (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: 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. 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'.


 

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.

 

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.



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. 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. The attenuator contacts oxidize and will need to be cleaned. Once cleaned and / or ‘re-sprung’ (sometimes a painstaking process) they should perform correctly. Manipulate attenuators rapidly, while monitoring a signal such as ‘white noise’ and see if the 'quiet' drivers start working (even if intermittently). 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).

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).


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


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 at low volumes.

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: 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.
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.
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 



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).

 

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 makes Gawd awful (motor-boating) noise periodically.  It even causes the meters to flutter 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.




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 / worn ‘idler tire’ / fast wind tire, or in extreme cases lubrication that has ‘gone south’. 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.
This 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 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).




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 in 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). It's being allowed 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.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.)
 



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).

 

 

 

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 35-40 years old (actually there are no ‘Real’ Reel to Reels made since about the mid 1990’s (no, that ‘strange’ 1/8” RCA doesn’t count, sorry) and like most R2R’s 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), completely cleaning and re-lubing. Once done, it will be good for another 20-30 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.


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. 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 later decks, it's typically done with a small amount of 'reverse' voltage applied to the 'supply reel motor'. Regardless, any of the measures to address the 'tape skewing' symptom, is beyond the scope of this page. Seek professional assistance for that one.
 

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). Also another 'tape related' issue is, is there a chance the tape is inverted (on upside down)? 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'.
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.
     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.

 

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. 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)

 

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: Change 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)
. 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.

 

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 those issues really 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.

A: I see this occasionally. After 25-40 years, flywheel / tuning string shaft lubes have become gelled / gummy. 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 actually ‘twist’ off and break the tuning shaft. 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).
 
 

 

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 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: 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.




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.




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 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’). 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.



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'.




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 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. Sorry, but we’ve essentially ‘written off’ restoring anymore of those units. They’ve cost us too much in time and money resources.


MISC HINTS / ISSUES:


 


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

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: 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.

Issue: The AC cord / plug prongs have a sticky green goo all over it...

A: This happens to AC cords / insulated wire over 25-40 years old. Probably some reaction between the copper and what ever is insulating it. You could try and clean the 'plug prongs / spades' with a proper solvent, and you should be OK. I've also seen this issue associated with another issue in that the insulation is breaking away from the plug housing, thereby exposing bare copper wire. That situation is not good, nor safe. The cord should be replaced and the balance of the unit's internals inspected for any other 'age related' issues.

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 much of a 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.
 



 

 

 

Please be patient while page loads . . .

 

LINKS TO OUR 'HI-FI' DEPARTMENTS

Amps and
Pre-Amps

Receivers

Cassette
Decks

Tuners

Turntables

8-Track Decks

CD Players

Reel-Reel
Decks

EQs and Signal
Processors

Speakers

Betamax and
VHS VCRs

Turntable Cartridges

Tube Audio

Ne'cessories

Speaker Parts

Record Players

Vintage Radios

Vintage
Walkmans

Headphones

Stereo Parts


Wondering where the "tone" you remember went?....

Vintage  Stereo Equipment receivers speakers Classic Silver Audio Collection and jerry

 

.... Surround yourself with Silver and find it again!



 



 
RESTORATION PROCEDURES    |  REPAIR RESOURCES  |  LINKS  


POLICIES, SPECIFICATIONS, AVAILABILITY, INFORMATION
AND PRICING SUBJECT TO CHANGE  AT ANYTIME  AND
WITHOUT PRIOR
NOTICE
and changes may not be posted to web immediately
.
 

 

Copyright © 1997-2014 Oak Tree Enterprises, LLC

COPYRIGHT INFORMATION

 

Please be patient while page loads . . .

 

 

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


_____________________________________________________________________________________________________