Audio Proz Service and Sales


Bellari RP533

Audio Proz Inv #: 60665

Modified with transformer, Automatic EQ compressor. This design allows deep bass and impulse response to be enhanced and less high frequency attenuation and clarity enhancement circuit. Unit has a ground modification and capacitor update for 6db noise floor improvement. This version has a 4560 op amp upgrade for line out balanced out. Mic pre amp RFI suppression capacitor. Modified with first stage tube harmonic bias control (right control) Cleaned switch with silver paste. #9 condition

$ 800  Contact Us  

Marshall 9005

Audio Proz Inv #: 27842

4-space rack design Stereo power amp, full TUBE design, Audio Pro modified. Designed by Marshall the Guitar amp co. Dual EL 34, converted to home audio quality hifi amp. Ruggedized, fresh tubes, call for details.

$ 780  Contact Us  

Bellari RP-533

Audio Proz Inv #: 23734

Heavily modified by Vince. 7 new switches, overdrive control, combo mic pre/comp/eq with many added features. Low noise high gain tube modification. 2 Band Bass/Treble. Front panel paid gain/phase switch. Tape saturation control. Smooth fast compression switch. High gain / bright switch. Power supply ground mod. Transformer EQ optical mod. This is the cats meow! Call for details 617-926-8020. Top flight cosmetic condition #8 with just a tiny bit of rack rash. 

Some additional information customers have asked about:   This unit is 90% all tube, the op amps are for RMS, DC control, balanced out not audio! What I do is make the circuits have more head room less noise better tube character and more correct RMS detector tracking. As you may have noticed the output circuit clips badly and is nowhere close to semi-pro level. It's a wrongly done balanced line op amp stage. Also the compressor threshold and ratio controls are too sensitive, as such the unit can go into a strange and not very likable distortion if pushed. There is some good basic design circuits in this, but just not enough. My mods are not about installing fancy parts it's about improved circuit performance

$ 680  Contact Us  

Denon DNT620

Audio Proz Inv #: 19049

CD/Cassette pro rackmount

$ 629  Contact Us  

Denon DN-T620

Audio Proz Inv #: 57966

Cassette/CD player. Rack mount. Top of the line unit. Auto reverse. Balanced line and RCA inputs and outputs. CD + Tape have pitch controls. Tested and calibrated OK. New. 10/10 condition.

$ 560  Contact Us  


We have thousands of items in inventory. To see our full inventory select the category under the Products dropdown menu, or at the top and bottom of each listing.


Art Pro Channel

Audio Proz Inv #: 54689

Modified vactrol variable transformer dynamic EQ, and variable tube bias mod. Professional tube microphone pre-amplifier. Tube/optical compressor. +48V phantom power supply. With true "tube gain cell" compressor. B stock.  See more details about the mod here, https://www.audioproz.com/AP.php?Article=19&Tab=Modifications

$ 548  Contact Us  

Bellari RP533

Audio Proz Inv #: 50898

Studio tube compressor/limiter preamp. AudioPro modifications to optimize tube gain and noise, power supply updates, phase switch pad and hi gain switch added on front panel. Excellent #9 condition.

$ 520  Contact Us  

EV Interface 2 Series II

Audio Proz Inv #: 61230

One of the best passive radiator designs, mods for improved power and midrange, pro use, e way passive radiator design, big bass sound, dark walnut look cabinet, medium brown grills, very minor fabric pulls at corner, minor stain can be painted with box, nice condition, rebuilt original parts, minor cabinet chip in back, original boxes available to ship, Audio Pro modified Rev. 4 x-over, monitors for midfield, #8+

$ 488  Contact Us  

Behringer Truth B2031P (pair)

Audio Proz Inv #: 56025

For sale Audio Pro Rev. 4/5 Modified passive version. New. 2 way passive monitor speaker (pair). Audio Pro modified. Rev 4 Design. Custom cabinet damping. Model 2031A are amplified speakers. I suggested 2031 passive design, and to use any good 40-100 Watt amplifier. Check out the Behringer website for a picture. A modified set is $448. We modify the 2031 to be a near field monitor where midrange tone is "warmer" or slightly receded image by a 3db through about at octave between 800 - 2000 H3. A far field monitor version is slightly brighter or stronger midrange and designed to listen at 4 to 8 feet distance. Basically flat response is perceived at that range. Near field version is for 2 to 5 feet away listening, and indeed most BSEE acousticians agree that a near field should be dipped in midrange. In both cases, the modification consists of improved multi section crossover (it presently has a very simple 4-part crossover) as well. We install a dampening blanket between the internal chambers, dampen tune one of the port slots and finally apply soft felt clone dampeners to improve midrange level and tonal match to crossover. The cabinet is now tuned to reproduce 40 Hz powerful and clean. The speakers are very heavy design with cast frame woofer, using high density MDF cabinet, very well done. No grill cloth is included by design. Shipping can be $38 or so to get them to you.

$ 488  Contact Us  

Electro-Harmonix hog 2

Audio Proz Inv #: 60025

Harmonic Octave Generator with expression pedal. New Condition

$ 480  Contact Us  

Dual 1218

Audio Proz Inv #: 60352

33, 45, 78 speed, pitch adjust, cueing, antiskate. With AT13a cartridge/stylus used but #8 condition. With original RCA cables, good quality.Nice condition, platter looks great, some minor wear, marks on wooden case. Dust cover in fair condition, missing approximate 2" piece broken off at lower back, another 2" crack in back has been taped. Overall condition #9. Call Vinc

$ 420  Contact Us  


We keep our database up to date with almost 10,000 items in stock. If you see a part number and a price, we have that item in stock.


Phase Linear 1000

Audio Proz Inv #: 56265

Auto correlator noise reduction system with Rev 6 modifications, low noise TLO75 IC update, some capacitor update. Dynamic range recovery system. Wood case, vintage knobs. Low frequency calibration. 9/10 excellent condition.

$ 388  Contact Us  

Philips GA312

Audio Proz Inv #: 59352

Belt drive, auto pick up at end of play only 33/45 pitch control, dust cover has crack left hinge, new belt installed, new phono cart at 92 with 311 stylus installed, (dent on center silver platter disk) basic service and maintenance, arm balanced, #8-

$ 368  Contact Us  

M-Audio LX4 Studiophile 5.1 Speaker System

Audio Proz Inv #: 58232

5 Small 2 way speakers. 6 inches wide, 9 inches tall, 6.5 inches deep. Black textured vinyl cabinet (no grills by design). 1 inch mylar dome. 4 inch cone/foam surround. Shielded, clear voice and mid bass. Designed as front left and right, and rear left, right and center channel expansion speakers. (Could be modified for improved fidelity). Powered subwoofer. 8 inch front face design. Black with black knit grill. Discreet 1/4 inch input only. Master volume for satellite speakers, separate bass level control. Basic clamp speaker outputs. Includes some speaker cable.

$ 368  Contact Us  

DBX DX-8

Audio Proz Inv #: 63330

Noise reduction module, 8 channel in/out, individual channel encode/decode. SN #21058. *Needs relay cleaning upon sale. Unit mint in original box, box is damaged/torn but repairable. #9 condition

$ 360  Contact Us  

Audio Technica ATW-1031

Audio Proz Inv #: 30167

Rackmount Wireless Diversity System. Belt pack frequency 13C (211 MHz). With 1/4" connection for guitar. Also includes AT-830cx Lavalier mic. Like new, #9 condition. ** Special Sale! **

$ 360  Contact Us  

JBL 2600

Audio Proz Inv #: 58298

Audio Pro in house total upgrade of woofer and tweeter. Tonegen Woofer tunes to 40 Hz, Silver Flute tweeter. Rev 3 Phase corrected crossover, Light Oak nice round cabinets. grills have small pull holes. #8+

$ 360  Contact Us  


Need your guitar or bass amp tuned up? We are now doing repairs, upgrades, and modifications to all types of guitar amps. Orange, Mesa Boogie, Fender, Marshall, Hughes and Kettner, Peavey, Ampeg, Gibson, Silvertone, etc. Read more about it here


Crate Stealth-50 GT-50

Audio Proz Inv #: 60360

With 16ohm Clestion Vintage 30 speaker, impedance speaker matching switch gives different tone qualities. Spring reverb. 4 6V6 Amplifier, excellent, 4 new Sovtek 6V6 tubes installed, 2 channel IN, multiband EQ, FX send loop, footswitch. 8/10 condition cleaned, calibrated, major super-ruggedization, doubled upon grounds, tested reverb/speaker. new fuse holder.

$ 348  Contact Us  

Symetrix 522

Audio Proz Inv #: 61364

Limiter, Ducker 2 channel, true balanced IC socketed op amp design. Uses Valley People VCA modules. Calibrated. Low use unit from Shop owners studio, No Rack Rash. #9 condition

$ 340  Contact Us  

Gallein-Krueger 400 RB

Audio Proz Inv #: 56215

200 watt bass amp with power cable. 1/4" input with -10db button. Volume/ 3 voicing filters/ treble, hi-mid, lo-mid, bass tone/ boost level with footswitch jack/ master volume/ 2 1/4" speaker outs 4 ohm/ direct out/ send, return on back. AP mod improved filtering capacitors grounds. Black with grey control panel. Minor marks around edges, covers. Low use, fully serviced. Has AC cord.  No rack ears (carry strap one side). 8+/10 condition.

$ 336  Contact Us  

ART PRO MPA II

Audio Proz Inv #: 57640

Two channel Mic/HiZ. M/S Matrix. Variable input Impedance. Variable plate voltage. QC- Lubed, Burn-in, switches exercised. #10 Condition (New).

$ 328  Contact Us  

Dual 1019

Audio Proz Inv #: 63441

Full automatic turntable. Nice walnut base (little chip on rear corner). 16/33/45/78 speeds. Pickering XV-15 Cartridge (available with 78 stylus). Fully serviced - Cleaned and oiled motor, rejuvenated idler wheel, adjusted pulley, + Headshell. Dust cover is in good condition - fine scratches, no cracks. Used good #8+ condition.  Note: Slightly prejudice on 33 groove lead in, Set up for use of 78's 

$ 328  Contact Us  

Crown Powerline Two

Audio Proz Inv #: 58562

PL-2. 2 Level adjuster. Output monitor jack. RCA input. Face plate is good condition but rack handels have obvious scratches. Complete service. Unit in low, 8 condition.

$ 300  Contact Us  


We have thousands of items in inventory. To see our full inventory select the category under the Products dropdown menu, or at the top and bottom of each listing.


Philips 212

Audio Proz Inv #: 60662

Electronic. 33/45 speed switch, stop switch, excellent suspension system. With used (low use) high quality ivory Audio Technica cartridge/Stylus, stylus is in alignment and good condition. All cleaning, pitch calibration. Plays great, suspension is set well, some minor marks on front of chassis, dust cover intact and looks good but logo has fallen off the top. #8 condition

$ 300  Contact Us  

EV PL20

Audio Proz Inv #: 58214

Modified mic with CAD 411 whole assembly retro fit into PL20 chassis hypercardioid triple non foam windscreen uses internal ev transformer sounds like RE 20 but can take more sound pressure more clarity. Mic is heavier has less microphonics slightly heavier output. Call for modification. I've done this mod for some fancy studios who like it. Very cool modern mic. 8+ condition.

$ 280  Contact Us