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 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 Video / CD / DVD / VCR / DAT / iPod / 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.


Optional Walnut Wood Soundcraftsment side panels currently available for this unit.
$85. pair

   

       NEW LISTING 5/14/10
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warranty
VINTAGE
  ADC / BSR
  STEREO GRAPHIC
  OCTAVE EQUALIZER
  "SOUND SHAPER"
  ONE TEN / SS-110-IC SS110IC
  #...1764
  Circa 1981
SOLD 7/7/10
  for sale
   We have just completely gone through this one. As the "EQ", Tape Monitor, and Record switches do not respond to the normal, simple cleaning on these ADC's, all three control "push" switches removed, disassembled, contacts individually burnished and completely cleaned with solvent for trouble-free service. This is a time consuming process, but the best way to insure performance. We injected both channels with 1kHz sine waves, and monitored switch performance on an oscilloscope with no visible issues after switch re-build. All fader LED's function. Great quality, dual 10 band EQ. Built very well and made for great "sonic" performance. These were one of the most sold EQ's ever made for a reason. Great sound, great looks and simple to use.
  
  Unit features:
  
- Dual 10 band, 'Octave' Graphic EQ  
- Each of the graphic controls feature a full +-12db of cut / boost (instead of the common 10 db)
  - Long, 60mm in throw length, high quality, linear, de-tented faders (most home units are 30 - 40mm)
- 10 frequency centers are as follows starting at the low-end: 31Hz - 62Hz - 125Hz - 250Hz - 500kHz - 1kHz - 2kHz - 4kHz - 8kHz & 16kHz.
- Dual Tape Monitors (Tape Monitors can also be used for Tape / Video / CD / DVD / VCR / DAT / iPod /MP3 / XM / SIRUS etc. as well as for CDR)
- EQ Recording function to imprint tapes / CD's / DAT's / Hard Drive with EQ curve for playback on a car stereo or to allow for deficiencies in speakers.
  - A-B Tape dubbing
  - EQ bypass
  - An un-switched AC convenience jack located on the back rated at 200 Watts

  Original Specs:
 
 # Channels: 2 (stereo)
 # Bands: 10 (combined L&R)
 # Cut / Boost dB's: 12±
 Max Output (RMS V): 10
 THD: 0.01% @ rated output, 20-20kHz
 S/N A-weighted: 110 dB

  EQ is in great shape and looks NEW. Again, we have completely gone through this unit and tested all functions. It works and sounds GREAT! Measures 15.25" wide x 8.25" deep x 6.25" tall and weighs 10 lbs unpacked. Includes our 90 day limited warranty.
  ADC / BSR SOUND SHAPER ONE TEN-IC
  Cond. 9
 $199.
SOLD 7/7/10

 

   

          

            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
 - -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!
 

-

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warranty
PRE-OWNED
DBX
TAPE NOISE REDUCTION UNIT
222
DBX TYPE II
  "WORLD AC POWER" ™
Circa 1981-83
for sale
Great for use with Reel to Reel decks or Cassette Decks. Blows Dolby out of the water! Used in Professional recording studios for years. Gets rid of tape hiss. Period! These separate units also sound better and do a better job of NR than the DBX chips built-in to many cassette decks, including the version in my personal deck, which I love. Will hook to any quality component system or analog studio deck. Will also accept signals from those rare DBX encoded LP's. Separate Level controls for Tape Recording / Playback and DBX Disc Playback located on rear panel. This unit is in great condition. We have completely gone through it cleaning all switches and controls as well as checking and / or re-soldering all RCA patching jacks on rear panel. Unit tests perfectly in both playing and recording tapes. We also tested using  existing DBX encoded tapes that were originally recorded using DBX Type 1 NR. Looks new, sounds and works great! True "WORLD AC POWER"™ 50 / 60 cycles there is a 110V, 120V, 220V & 240V selector for use anywhere in the world! This is a "Made in Japan" version, not Taiwan or China. Measures 17.25" wide x 9" deep x 1.75" (1 rack space) tall and weighs 8 lbs unpacked. Includes our standard 90 day limited warranty.
DBX 222
Cond. 8.5
$139. (C)
C.B.S.

           NEW LISTING 5/7/10
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warranty
VINTAGE
PIONEER
DYNAMIC PROCESSOR
            RG-9 RG9 RG-2 RG2
  "WORLD AC POWER" ™
Circa 1982-'83
#...777S
for sale
Super clean "Champagne" Matte Dynamic Processor. Striking Green Fluorescent display that pulses with the beat. Features Include:

- Expansion depth is completely variable for custom tailoring to your tastes
- This unit really brightens up your sound and makes it come Alive
- These are similar to a DBX 3BX or an Aural Exciter
-Rear panel includes a selectable -6db attenuator for use with pro-gear
- True " WORLD AC POWER"™ Operates on 50 / 60 Hz AC and voltages from 110-240 AC
- 100 watt, un-switched AC convenience outlet is also on the rear panel

Specs:
Dynamic Expansion: 4, 7, 10, 13, 16 dB
Attack Time: 0.3 mS
Release Time: 120 mS
S/N Ratio: 100 dB
THD: 0.05%

We have completely gone through it cleaning all pots and switches. Dynamic processors are a "subtle" effect, and should be anticipated as such. Looks good with only very minor wear and sounds great! Measures 16.5" wide x 14" deep x 6" high and weighs 18lbs unpacked. Includes our standard 90-day limited warranty!
PIONEER
RG-9
Cond. 8+
$199.
 
 

  SOLD ITEMS BELOW

NEW ADDITION 4/2/10
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 warranty
               AudioSource Audio Source
 STEREO OCTAVE
GRAPHIC EQUALIZER
           EQ-100  EQ100  
 #...3100
  Circa 1998 
SOLD 4/19/10
  for sale
  We have completely gone through this unit, checking all controls for cleanliness and I/O solder joints and re-flowing where necessary. All functions tested for perfect operation. All inputs tested and both side produces clean and even sine waves! No power supply hum of any kind. It's dead silent!  All inputs tested and both side produces clean and even sine waves! Checked with O-Scope. No power supply hum of any kind. It's dead silent!
  ____________________________

Great looking and quality AudioSource 10-band  stereo, graphic EQ. The Audio Source EQ-100 covers the following frequencies: 30Hz, 60Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz and 16k. Each frequency also allows cut / boost of a full 12 dB (most home EQ's are only a maximum of 10 dB + or - ).
Features include:

- Stereo 10 graphic bands
- 1 Octave centers
- EQ defeat
- EQ Recording function to imprint tapes / CD's / DAT's / Hard Drive with EQ curve for playback on a car stereo or to allow for deficiencies in speakers.
- Tape Monitor (Tape Monitors can also be used for Tape / Video / CD / DVD / VCR / DAT / iPod /MP3 / XM / SIRUS etc. as well as for CDR)
- 10 Band 9-segment, LED, Spectrum Analyzer style display
- AC convenience outlet on the back panel (un-switched @ 200 watts capacity)

Original Specs:
 
 # Channels: 2 (stereo)
 # Bands: 10 (combined L&R)
 # Cut / Boost dB's: 12±
 Max Output (RMS V): 10
 THD: 0.03% @ rated output, 20-20kHz
 Frequency Response: 5-100kHz
 S/N A-weighted: 80 dB

This is a good looking and performing EQ. EQ built using super quality, de-tented linear controls  with a compact 30mm throw! Again we have completely gone through cleaning it & checking all functions. All controls and switches cleaned for worry-free service. With the exception of a few minor scuffs on the top plate (not seen when in a component stack), the unit looks great. Measures 16.5" wide x 8.75" deep x 2.75" high and weighs 9 lbs unpacked. Includes our standard 90 day limited warranty.
AudioSource EQ-100
  Condition 8.5
  $139.
SOLD 4/19/10

    

NEW LISTING 4/4/10
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 warranty
 PIONEER
 DYNAMIC PROCESSOR
        EX-9000 EX9000
 Circa 1991-'93
SOLD 04/26/10
 for sale
Modern recording commonly uses a couple different techniques that may detract from the original signal. These are necessary 'evils' to allow the signal to 'fit' onto tape / record / mp3 formats. They are one 'Limiting' which puts a 'lid' on transient peaks / attack, two 'Compression' which 'squishes' overall signal. The Pioneer EX-9000 can reverse those effects. It is built on the pioneering RG-1, RG-2 and RG-9 models, but takes sonic ability many levels beyond those units. Very similar in performance to the very expensive DBX 3BX III or  Aural Exciter units. Restores the impact and dynamic range of the original performance. Striking Fluorescent display that pulses with the beat. Expansion depth is completely variable for custom tailoring to your tastes. Dynamic range can be extended to 96dB!!! This unit really brightens up your sound and makes it come Alive!
 Features:

- 3 separate controllable bands (Low 20-100Hz, Mid 100-2.5kHz & High 2.5kHz-10kHz)
- Hard / Soft selector switch
- Selectable -6db attenuator for use with pro-gear.
- Connects simply via 'Tape Monitor' , 'Adaptor' loop or 'Pre-Amp / Pwr-Amp' loop.
- Un-switched convenience AC outlet rated at 100 watts


 Specs:
 Attack Time: 4.7 mS
 Release Time Hard / Soft: 68 mS / 2.7 sec.
 THD: 0.8%
 
 We have completely tested unit for correct function and sonic quality. Looks like new and sounds great! Will include a copy of the owners manual, so you can appreciate the most out of the unit. Measures 16.5" wide x 2.5" high x 8.5" deep and weighs 7 lbs unpacked. Includes our standard 90-day limited warranty!
 PIONEER EX-9000
 Cond. 9.5
 $249.
SOLD 04/26/10

** "(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.