Audio Proz Service and Sales


Yamaha PG1

Audio Proz Inv #: 72736

Full feature unit with effect send levels IN/OUT Guitar Preamp with Guitar distortion, multiband EQ, 2 channel switching, double spring reverb, (modified to make rugged and dampened spring pan for cleaner brighter spring sound, nice shorter delay / decay spring). Original spring pan. 1/4"  & XLR outs. #8+ condition

$ 360  Contact Us  

Yamaha C-60

Audio Proz Inv #: 25276

Modern, semi-audiophile unit, 4-bd eq, black modern unit, tuner, phono, aux, tape, phone jack, mute, eq bypas etc.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

The Apt/Holman Preamp Owners Manual

Audio Proz Inv #: 43093

Original Owners manual #8 condition, minor scratches on front cover. With Schematic included.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Telefunken v72

Audio Proz Inv #: 42049

12 pin (blade type) multi-pin connector, modular type design, locking latch on front panel, all metal chasis, untested but unit is totally intact and all internal cicuits look good

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Technics SU-9200

Audio Proz Inv #: 27655

Stereo Preamp, Excellent condition, very good cosmetic, Stereo Control Center, Inputs-(Tuner, 2 aux, 2 phono, 2 tape monitor loops) gain control for phono 2 / 20db Mute Switch, phono impedance controls, Toned dereat, L/R bass and treble controls, bass and treble filters, stereo, reverse L+R, L, R, Mode switch, sounds like/design similar to MAC preamps (individual resistor/circuits for tone control) highest quality parts used.

SOLD  Contact Us  

Contact us about similar items or replacement parts.


OUT OF STATE CUSTOMERS:
Contact us if you are interested in purchasing an item.
We prefer PayPal payments.
We only ship to VERIFIED PayPal Addresses
For customers who do not have a PayPal account we also take Credit Card over the phone.

Please be aware that there is a minimum $4-$6 to ship any part.


Technics SU-9070 Preamp

Audio Proz Inv #: 38159

Stereo Preamp, complete, excellent mechanical and cosmetic condition. Ruggedized, updated, cleaned and calibrated. Nice Unit.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Sumo Athena Preamp

Audio Proz Inv #: 9763

Total discreet class A circuits throughout, shielded transformer, high quality level control and switch $800 for complete Sumo System, Polaris amp, Athena Preamp, and Aurora Tuner

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Sumo 0620 Stereo Pre-amp

Audio Proz Inv #: 21849

Class A circuitry design pre-amp, very clean sounding unit, very good condition black one-sapce rack mount.

$ 300  Contact Us  

Stanton 310

Audio Proz Inv #: 46055

Phono Stereo preamp, with dip switches for cartridge impedance matching. Uses RCA in and professional screw terminals out. Unit can operate at AC 120 or 230 volt. Excellent #9 condition.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Sonic Frontiers Line 1 Amp

Audio Proz Inv #: 63522

Tube preamplifier, with a spare E88CC tube and garden hose style Essence AC cord. This unit has (4) JJ 6922 tubes from original design, and (2) 6DJ8 vintage (looks to be Mullard from Great Britain) installed in later stage for better harmonic distortion levels (about .1%). This unit is in #9+ condition!

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Shure M64

Audio Proz Inv #: 43886

Shure M64 stereo preamp. 2 channels, RCA ins/outs, equalization switch for phono, flat, or tape.

SOLD  Contact Us  

Contact us about similar items or replacement parts.


All Remotes are now 25% off or Free Shipping!!!  (Reel to Reel remotes excluded).


SAE P102

Audio Proz Inv #: 9224

Stereo preamp, programmable tone settings, 2 rack space, re-enforced all ground connections on RCA jacks and cleaned and serviced, excellent condition

SOLD  Contact Us  

Contact us about similar items or replacement parts.

SAE MK1B

Audio Proz Inv #: 18809

Super-quality hand wired boards, low noise, hi-accuracy controls, 7 bnd EQ, 8 AC sockets, 3-space rack mt - speaker add on cable for interfacing amp

SOLD  Contact Us  

Contact us about similar items or replacement parts.

SAE Mark 1B

Audio Proz Inv #: 43246

Stereo pre and equalizer. Inputs: Phono 1 & 2, Aux 1 & 2, tuner. 3 tape monitor loops, 2 speaker sets, balance and gain controls, 7 band equalizer. Cap + Coil circuit. Class A Transistor design. Resoldered boards at equalizer circuit. #8- condition with minor scratches on top cover. Power switch glued in place.

$ 680  Contact Us  

Rotel RTC-940 AX

Audio Proz Inv #: 41699

Tons of control, 8+ FM digital memory. Aux, CD, Tape 1/2 inputs. No phono inputs. Slim-line, black color (Adcom look), with remote. Excellent, #9 condition with box.

$ 300  Contact Us  

Rotel RQ-970 BX Phono Pre

Audio Proz Inv #: 71215

MM & MC inputs, Simple slimline design using super low noise AD744 OP amp. about 6db of gain extra for MC.  Audiophile grade components. Bench test QC, all OK. #9 condition 

$ 188  Contact Us  

Rotel RC-970BX

Audio Proz Inv #: 62303

Stereo Control Amplifier (preamp), black face, very simple layout, bass/treble, tone on/off, tuner/cd aux/tape 1/tape 2 inputs, tuner/cd/aux/tape 1/tape 2 REC out selectors, excellent condition, very clean, easy to use, 2 hairline scratches right hand corner

SOLD  Contact Us  

Contact us about similar items or replacement parts.


Need an APT unit serviced or modified? Vince, the owner of Audio Pro, ran the production line at APT for many years, and has decades of experience working with APT products. Read all about our APT Holman service and mods here. Also read about the APT Moving Coil Phono Mod Here.


Realistic Stereo Pre-Amplifier 42-2101

Audio Proz Inv #: 42483

RCA out, mic 1/4" stereo inputs, phono RCA in.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Realistic 42-2930

Audio Proz Inv #: 27652

Phono Preamp - Solid State Stereo Pre-Amplifier, Small wall or cabinet mount box. Single Stere input/output device powered by AC line cord.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Pyramid SEA-2500x

Audio Proz Inv #: 45446

Tuner, Aux, CD, Phono, Mic inputs. Bass, Mid, and Treble EQ controls. Made minor modifications to make perfect level and EQ match between channels. New stock, QC'ed.

$ 185  Contact Us  

Pyramid SEA-2500 x

Audio Proz Inv #: 45445

Stereo preamp with Tuner, Aux, CD, Mic, and Phono inputs. Tape, mono, low filter, and muting buttons. Bass, mid, treble, and volume controls. Super tweek modification to EQ and find adjustment of balance. Professionally cleaned and serviced, all controls checked and OK.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Pyramid SEA 2500

Audio Proz Inv #: 63815

Basic Preamp. This is an excellent quality product, with high quality controls, switches. Input switching IC is same as expensive products. Low noise op amp for phono. 3 band eq. Some ground mods were done. rack mount. #9 condition

$ 128  Contact Us  

Pioneer SPEC-1

Audio Proz Inv #: 47386

Full function stereo pramplifier, silver face, 120/240v switchable, fully cleaned and tested, truly excellent cosmetic condition.

SOLD  Contact Us  

Contact us about similar items or replacement parts.


Customers outside of the US, please note that international shipping can be costly (US Post $16 minimum - up to 8oz or 226g). We are glad to combine orders to reduce shipping costs. Take a look at our shipping policies for more information and estimates of prices and shipping time.


Phase Linear 4000 autocorrelation preamplifier

Audio Proz Inv #: 63872

Discrete transistor phono preamp. Has discrete version 4 channel decoder board and Phase Linear updated / best version auto correlator.  RCA's in excellent condition.  SUPER SPEC CALIBRATED ! channel balance +/- 1db or better (one of the most accurate units we have seen) 90% Of all power supply caps replaced & upgraded at boards and main supply. Upgraded grounding on boards and ruggedized solder at board connectors.   ( By design this version 4000 does not lower the audio out signal to totally off at the back panel RCA. A very low level audio signal will always exist. The unit can be modified with a few resistor changes to be totally off if requested at sale)   Low use unit, face and knobs #9 condition

$ 680  Contact Us  

Phase Linear 4000

Audio Proz Inv #: 62305

Autocorrelation preamplifier. Unit has seen extremely low use time. All controls switches board connectors cleaned corrected power supply per Phase Linear update, some IC sockets and best noise version op amp installed. Repaireds some RCA inputs and fortified them with glue. Replaced various capacitors anywhere in unit which measured off spec (about 20 caps changed). Install "star ground" modification to reduce noise and RFI ruggedize all board connectors auto corrector circuit. Spec of unit noise floor and channel matching is excellent! Tracks excellent +/-1db channel match!

SOLD  Contact Us  

Contact us about similar items or replacement parts.