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,
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 for sale.
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 for sale. Yamaha, ADC SS EQ, Bose 901 E EQ equalizers & reverbs for sale.
 

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
(Click on above thumbnails to enlarge photos)
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

(Click on above thumbnails to enlarge photos)
warranty
PRE-OWNED
JVC STEREO
GRAPHIC EQUALIZER EQ
SEA-50 SEA50
10-BAND
Circa 1978-82
SOLD 2/1/10
for sale
Very easy to use and good quality JVC 10-band "combined" stereo, graphic EQ. This JVC "SEA" covers the following frequencies: 32Hz, 63Hz, 12.5Hz, 125Hz, 250Hz, 500Hz, 1kHz, 2kHz, 4kHz, 8kHz and the last band is selectable 12k / 16k / 20kHz. Each frequency also allows cut / boost of a full 12 dB (most home EQ's are only a maximum of 10 dB + or - ). Other features include:

- 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.
- Dual tape monitors with Tape 2 having redundant RCA I/O's on the front panel
- Dual AC convenience outlets on the back panel (1 switched & 1 un-switched @ 100 watts capacity each)
-  "WORLD AC POWER"™  50 / 60 cycles there is a 110V, 120V, 220V & 240V selector for use anywhere in the world!

This is a good looking and performing EQ. Has a bit of minor scuffing along the top edge of the face plate and normal wear to back case. EQ built using super quality, de-tented linear controls  with a full 70mm of throw! We have completely gone through cleaning it & checking all functions. All controls and switches cleaned for years of worry-free service. All function indicator lamps checked and / or replaced. Measures 16.5" wide x 13" deep x 6.75" high and weighs 16 lbs unpacked. Includes our standard 90 day limited warranty.
JVC
SEA 50
Cond. 8
$129. (C)
C.B.S.
SOLD 2/1/10


 

-

(Click on above thumbnails to enlarge photos)
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
$109. (C)
C.B.S.

  SOLD ITEMS BELOW

 

         NEW LISTING 8/29/09
(Click on above thumbnails to enlarge photos)
warranty
PRE-OWNED
REALISTIC
DUAL 12 BAND STEREO EQ
       MODEL 31-2009 312009
SOLD 12/19/09
 for sale
 Classy looking silver face, Realistic 24 band Equalizer (12 bands per stereo channel). Dual Tape Monitors with bi-directional dubbing. Output level control. Built in Dynamic Range Expander. This is actually one of the best sounding EQ's we have had come through the site! Very "musical" sounding with lots of clarity and punch.
 Unit is clean both cosmetically and sonically. Looks fine and sounds great! Un-switched, 200 watt AC outlet on rear panel. We have completely gone through it, checking all functions. Includes our standard 90 day limited warranty.
REALISTIC 31-2009
 Condition 8.5
 $179.
SOLD 12/19/09

** "(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.