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

STEREO EQUALIZERS, REVERBS / SIGNAL PROCESSORS VINTAGE AND USED

Used / vintage stereo EQ's / equalizers by Pioneer RG-2, EX-9000, Sansui RA-500, RA-700, RA-990, SR-202, spring reverbs & delays. DBX dynamic range expanders, switchers, selectors & noise reduction units DBX 200, 007, 200X, 222, 224. Pioneer SR, RG, 202w 60, 90, 303 reverbs & delays. Teac Pioneer Kenwood AT-80, DT-5, 510 Audio Timers & Sansui RG-700, 710, SE-9, Equalizers. BIC FM8 Beam Box. JVC SEA-80, 50, EQ's. Yamaha, ADC SS EQ, Bose 901 E EQ / equalizers & reverbs.
 

AUDIO EQUALIZERS
and our philosophy on them.
   
                               "Are Equalizers really necessary? I just paid $30 grand for my speakers. They shouldn't need any EQ. Right!??"

Short answer is probably yes, an EQ will generally be beneficial to most systems.
     Most speaker designers strive to make a speaker's curve as "flat"* as their projected size parameters and target retail price will allow. The human hearing curve is not "flat". Most folks' hearing is accentuated in the midrange (it's where the human voice is centered) and attenuated in the bass and treble. Sort of a reverse "rock-n-roll smile" curve. When you hear a good, "flat" response speaker, it will likely appear to have an over abundance of mids, at least for most listeners. It will also likely have a deficiency in bass and possibly treble. It will most likely sound  "thin", the degree of which can vary from slight to extreme, depending again, on many variables. This might not even be readily apparent when auditioning speakers, but generally if you hear a pair speakers with an appropriately adjusted, EQ engaged, then you listen to it bypassed, you will want to re-engage it as quickly as possible.
     The classic arguments against using an EQ have been that an EQ, or any additional inserted signal processing device, makes the signal path less "pure" and adds noise. Also, again, "these speakers were expensive and shouldn't need an EQ". To address the first point, this issue can usually be reduced to a more than desirable point by utilizing a high quality EQ or signal processor. The noise floor should certainly be below audible levels, and it doesn't take too much of an EQ to achieve that for most folks systems.  While the first point is valid, a good EQ's benefits usually far outweigh any minor noise issues, which are probably below most listeners audible limits in the first place. The second issue was answered previously, in the above paragraph.   In fact, the better the speakers, the more they would likely benefit from a reduction of the midrange frequencies, due to their as "flat as possible" curve. Again, this would apply to the average persons hearing curve. Some "cheap" speakers, will have a "rock-n-roll smile" EQ curve built-in by utilizing drivers, crossover and cabinet combinations, that have an over abundance of bass and treble, and a deficit of mids by design. That would beg the question of "why wouldn't they all just do that then". The answer to that is that any respectable speaker manufacturer wouldn't try and dictate a built-in curve into a speaker other than as flat as assigned parameters will allow, for a number of reasons.
     Another less apparent, but still valid reason for utilizing an EQ can be to compensate for listening room acoustic characteristics. This is generally more difficult to assess, but overtime could become a desired need. This need would obviously change with any parameter change in the listening environment. Also, and no offense, but as we age and as we are exposed to various, sometimes, injurious sonic environments and events, our sensitivity to frequency ranges will change.
     One way to look at a specific speaker / listening environment combination is to think of it as a blank artists canvas. A really high quality speaker system would be comparable to a high quality canvas, brushes and material. Said another way, a "non-flat" EQ curve / listening environment / speaker combination is akin to starting your painting with a dirty, blotchy canvas. The listening environment to a well lit room with natural lighting, conducive to a creative mood. Until you "shape" the EQ, there is no painting on the blank canvas. Once you shape the EQ to your tastes, in a way that compliments the speaker design / room combination, you have created your work of art.

    While I can appreciate all the arguments for not using an EQ, in the end, I generally use an EQ with it's curve slightly boosted in the bass and treble frequencies and attenuated through the mid frequencies from "Zero" position (the "rock-n-roll smile" curve). It will usually require adjustment following any change in speakers, listening environment parameter adjustments and with the material I am listening too. I also have a 1/3 octave RTA monitor / spectrum analyzer with a pink noise generator and analyzing mic to establish an accurate "flat" point to start from.

 * Contrary to a somewhat common misconception, "Flat" does not mean "dull". "Flat" refers to the graphic "curve" of a speakers output when analyzed by a spectrum analyzer. Ideally a speaker should be able to reproduce the human hearing range with all frequencies as close to "zero" (even amplitude or "flat") as is practical for the intended design / price point levels. The listener can then modify it from there by various methods (usually some sort of signal processor such as an EQ) to their tastes.


 

 

         NEW LISTING 8/29/09
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warranty
VINTAGE
SOUNDCRAFTSMEN
DUAL 10 BAND STEREO EQ
       MODEL RP2215-R  RP2215R

 The Soundcraftsmen RP2215-R, Audio System Equalizer. Great quality dual 10 band EQ. This is the EQ only version of the Pre-Amp / EQ that is the "heart" of our main audition system here at Oak Tree Vintage. Each of the graphic controls feature a full +-15db of cut / boost and are an extra-long 50mm in throw length (most home units are 30mm).
 Features:
 
 - One Octave Graphic EQ
 - 10-Band, Graphically controlled frequencies per channel
  - +- 15dB Cut / Boost (most do only 10 dB)
 - The 10 frequency centers are as follows (starting at the low-end):
 30Hz - 60Hz - 120Hz - 240Hz
 - 480kHz - 960Hz - 1,920Hz - 
 3,840kHz - 7,680Hz & 15,360kHz.
- Variable Input Level with Unity Gain assist indicators
- Standard 19" Rack-mount
  - 50mm Linear Pots
  - Tape Monitor
 (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc) Dubbing can be used with CDR (CD recorders) units)
  - EQ Record function, for imprinting EQ curve to recordings
  - EQ defeat / bypass
- Un-switched AC convenience outlet on rear panel
 
 Original Specs:
 
 # Channels: 2 (stereo)
 # Bands: 10
 # Cut / Boost dB's: 15±
 Output (RMS V): 10
 THD: 0.01% @ rated output, 20-20kHz
 S/N A-weighted: 114 dB
 
 Again we have completely gone though this unit testing all functions. It was then "burned" continuously for 72 hours. EQ is in great cosmetic shape and looks near NEW and sounds GREAT!  Measures 19" wide x 11" deep x 5.25" high and weighs 12 lbs unpacked. Includes our 90 day limited warranty.
SOUNDCRAFTSMEN RP2215-R
 Condition 8.5
 $329.
SOLD 10/11/11


Optional Walnut Wood Soundcraftsment side panels currently available for this unit.
$85. pair
SOLD 10/11/11

   

          

            NEW LISTING 5/10/10

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warranty
VINTAGE PIONEER
STEREO
REVERB AMPLIFIER / DELAY
                SR-303 SR303 SR-9 SR9

The SR-303 is "The-must-have" signal processor for the most desirable, 'Silver-Face / Blue Meter' Pioneer rack mount gear series.  Pristine Silver face electronic Reverb / Delay. Unit features  really 'Cool' "Time-Tunnel", Blue display that pulses with the beat. If you choose, you can display it even if you have the effect bypassed. Reverb / Delay depth and time are completely variable for custom tailoring to your tastes. Either effect can be added to recording so you can transfer the sound effect to your auto.  

Features include:
 - Electronic Reverb / Delay depth and time is completely variable for custom tailoring to your tastes
 - 'Reverb Record' feature allows effect to be added to recording so you can transfer the sound effect to your auto
 - Pulsing Green reverb level display
 - Depth control
 - Time Delay control
 - Tape monitor  (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc) Dubbing can be used with CDR (CD recorders) units)
 - -6dB attenuator on rear panel
 - One un-switched AC convenience jack located on the back rated at 100 Watts
 -  "WORLD AC POWER"™  50 / 60 cycles there is a 110V, 120V, 220V & 240V selector for use anywhere in the world!
 
Specs:
Input Sensitivity / Impedance: 150mV / 150Ω @ 1kHz (@ 1kHz /  'Depth' set @ '0')
Output Sensitivity / Impedance: 150mV / 150Ω @ 1kHz (@ 1kHz /  'Depth' set @ '0')
Maximum Input Level: 2000mV (2V) (@ 1kHz /  'Depth' set @ '0')
Frequency Response: 5Hz-70kHz ± 1dB (w/ 'Depth' set @ '0')
Reverb Time (effect 1): 0-3 Sec @ 400Hz
Reverb Time (effect 2): 25-100mS @ 400Hz
S/N Ratio: 90dB (@ 1kHz / 1V input & 'Depth' set @ '0')
THD: 0.05% (@ 1kHz / 1V input & 'Depth' set @ '0')

Again, we have completely gone through it cleaning all pots and switches. All functions tested perfectly. Looks and sounds great! Measures 16.5" wide x 4" high x 13" deep and weighs 10 lbs unpacked. Includes our standard 30-day limited warranty!
 PIONEER SR-303
 Cond. 8.5++
 $279.00
 
 Note: These units are really impressive when paired up, using one unit for reverb and one for some slight "slap-back" delay. While both effects are available on each unit, it's only one at a time. With two units you can get the full "LIVE" effect, just like in pro-audio systems!
 

NEW ADDITION 2/4/11
 (Click on above thumbnails to enlarge photos)
  warranty
VINTAGE  
FISHER
 AUDIO TIMER
        TR-3000 TR3000
 Circa 1980-81
 Made in Japan 
   "WORLD AC POWER" ™
 for sale
 Fisher TR-3000 Audio Timer. These were originally designed for setting your system to record scheduled FM radio shows and Album rock. They also can be used to turn your system into a Super-Hi-Fi Alarm clock radio and / or just as the ultimate and really cool digital clock.
Features:
- 24 Hour 'Military' Time (as we are located in Colorado Springs, this unit was likely brought back by a GI)
- 'Sleep Timer' function from 1:59-1 minutes
- 4 'Switched' AC outlets
- 'Auto-Dimming' senses room light level and raises readout
- Rear located, variable 'Brightness' control for the readout
 -  Semi "WORLD AC POWER"™  50 / 60 cycles, but will need a transformer / converter for 'non-North American' AC voltages / use.

This is from a collection of these that took us a long time to amass. Many of these will erratically change / advance the time after they've been on for 1 or 2 hours. This is one of the few out of the many we get that keeps time perfectly and was checked over a 1 week period. Entire unit was disassembled and cleaned inside and out, including the internal switches. All functions test perfectly. Aqua Blue Fluorescent digital readout and black face plate. Use it to turn on most anything with a latched or mechanical power switch. Will switch up to 500 watts via 4, rear located AC outlets. Unit looks near new and works great! Clock memory is volatile at power outages. Measures 17.25" wide x 5.25" deep and 1.75" high and weighs 4 lbs unpacked. Includes our standard 90 day limited warranty.
FISHER TR-3000
 Cond. 8.5+
 $129.

 

  SOLD ITEMS BELOW

    

   

NEW ADDITION 5/27/11
(Click on above thumbnails to enlarge photos)
warranty
VINTAGE
JVC
GRAPHIC EQUALIZER EQ
        SEA-80 SEA80
W/ MICROPHONE
#...4756
STEREO OCTAVE 10 BAND
Circa 1979-83
  "WORLD AC POWER" ™
MIJ
SOLD 6/29/11
Unit was disassembled extensively for restoration / reconditioning. All toggle switches painstakingly 'triple' cleaned. Linear faders still clean and retain their 'smooth' feel. Display level pot cleaned extensively. While the original pilot lamps was working, we replaced it with a fresh unit. International 'World AC Power' selector set to correct voltage for North America. We then tested both channels with a test tone and O-scope, analyzing both channels with and without each independent effect. It was then cleaned inside and out, then polished to near new look.
 Unit is clean both cosmetically and sonically. Looks and sounds great! Very 'musical' sounding. Check out the S/N ratio below...
 ______________________________

Great design, build quality with no-excuse sonic quality and very easy to use. The JVC 10-band stereo, graphic EQ w/ Pink Noise generator and RTA. This combined with an analyzer mic allows perfect adjustment for your speakers / room to 'True Flat'.
Other features include:

 - One Octave Graphic EQ
 - 10-Band, Graphically controlled frequencies per channel
  - +- 12dB Cut / Boost (most do only 10 dB)
 - 10 frequency centers are as follows (starting at the low-end):
 31.5Hz - 63Hz - 125Hz - 250Hz - 500kHz - 1kHz - 2kHz - 4kHz - 8Hz & 16kHz.
- Pink Noise Generator built-in w/ selectable L or R or L+R output
- RTA (Real Time Analyzer) for visually monitoring and adjusting room acoustics w/ 'Memory Hold'
- Left and Right selectors for RTA
- RTA level adjust
- 1/4" RTA mic input
  - LONG 70mm Linear faders utilizing super quality potentiometers
 - True Tape monitor with both RCA and DIN I/O's. (Tape Monitors can be used with Tape / Video / CD / DVD / VCR / DAT / MP3 / iPod® / iPhone® / iTouch® / iGadget / MP3 / XM® / SIRUS® CDR (CD recorders as well as for inserting signal processors, such as EQ's, Reverbs, Spatial Enhancers / Dynamic Processors, Noise Reduction units, Special Effects units, Time Delays, etc) Dubbing can be used with CDR (CD recorders) units)
  - SEA EQ 'Record' function, for imprinting EQ curve to recordings
  - EQ defeat / bypass / -6dB pad
- Externally accessed protection fuse
- Dual AC convenience jacks located on the back, one 'un-switched' and one 'switched'' rated at a total of 200 Watts
 -  "WORLD AC POWER"™  50 / 60 cycles there is a 110V, 120V, 220V & 240V selector for use anywhere in the world!
 
Original Specs:
 
 # Channels: 2 (stereo)
 # Bands: 10
 # Cut / Boost dB's: 12±
 Max Output (RMS V): 6
 THD: 0.003% @ 1k and @ rated output
 IMD: 0.003% @ 1k and @ rated output w/ all faders set to '0'
Gain: 0 dB on 'Defeat' mode
 Frequency Response of electronics: 10-100,000Hz
 S/N A-weighted: 118 dB!!!
 Pink Noise output level: 50mV RMS
 Input Impedance: 47k Ohms
 Output Impedance: 100 Ohms

This is a great looking and performing EQ and is built using super quality, de-tented linear controls  with a full 70mm of throw! Again, we have completely gone through cleaning it, refurbishing  & checking all functions. All controls and switches cleaned for worry-free service. VERY well built, super clean (check out the THD rating), virtually NO crosstalk and sounds fabulous. Measures 17.75" wide x 12" deep x 6.25" high and weighs 17 lbs unpacked. Includes the original JVC MD-S50 'Pink Noise microphone'! Also comes with original box, packing and a copy of the users manual. Includes our standard 90 day limited warranty.
JVC SEA 80
Cond. 9+
(C)
M.R.
SOLD 6/29/11

** "(actual as measured)" refers to original test results done by Hirsch-Houck Laboratories upon test release of product when new. Current "aged" specifications / performance may of course vary from that.