Audio Proz Service and Sales


Ortofon MCA76

Audio Proz Inv #: 17004

moving coil preamp

SOLD  Contact Us  

Contact us about similar items or replacement parts.

NAD 1130 Stereo Preamplifier

Audio Proz Inv #: 43200

Phono/Aux/CD/Tape1/Tape2/Tuner in. 2 outputs, 2 band bass/treble tone control. Capacitance load switch. Does moving cartridge or moving magnet. #8+ condition with some minor scratches on top cover. All controls and switches cleaned. Fully tested. No noise or modulation.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Nikko Beta 50 II

Audio Proz Inv #: 17049

Stereo Preamp, On front panel 2 input mixing/monitor, 3 external processor loops, resoldered, modified, cleaned, new power supply

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Nikko Beta 30

Audio Proz Inv #: 25159

Stereo preamp with box, packing, and manual, 1 1/4 rack space (non standard) power supply mods, 2 simultaneous ins/outs, sound proc loop, phono, tape monitor, bass treble

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Fisher #50 C-4

Audio Proz Inv #: 6637

Tube mono, w/manual - 78 equalizer.

SOLD  Contact Us  

Contact us about similar items or replacement parts.


We are presently operating on an APPOINTMENT ONLY basis. Please call us first at (617) 926-8020 to schedule an appointment before you come into the shop for repairs, rentals, product recommendations, consultations, or anything other than minor purchases.


Luxman 5C50 Pre-amp

Audio Proz Inv #: 24127

Absolute top quality Class-A circuitry! Open discrete op-amp module upgrades. Low-use time, excellent condition. Part of matching 3-piece set. Also included are Luxman 5M521 Amplifier (see # 24128 in amplifiers), and Luxman 5T50 Tuner (see #24126 in receivers). We would like to keep this beautiful system together, so the PRICE IS FOR THE WHOLE SYSTEM not just the preamp.**SPECIAL WHOLE SYSTEM SALE**

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Crown Straight Line 2

Audio Proz Inv #: 26275

Mint Condition, 1-rack space preamp, audiophile quality preamp with highest quality op amp, caps, connector controls, and circuit board. 2 aux ins, 2 tape inputs/dubbing, and processor loop, monitor switch L/R mono reverse switchable/defeat tone controls, Nice Style.

Although these Crowns are excellent preamps they are not significantly different than an APT (which actually has a better phono pre) or an Adcom. Those two are both 2 rackspaces though.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Adcom GFP-750

Audio Proz Inv #: 27515

Minimalist version, no tone controls - volume only, balance control, processor loop, stereo/reverse/mono control, cd balanced input + RCA, balanced main outs + 2 RCA, cleaned controls, excellent conditon - with remote

SOLD  Contact Us  

Contact us about similar items or replacement parts.

ART DJ PRE II

Audio Proz Inv #: 63959

Top quality phono preamp with gain control and cartridge loading select.  Includes DC power supply, New in box

SOLD  Contact Us  

Contact us about similar items or replacement parts.

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.

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.


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.


APT Pre Preamp Board

Audio Proz Inv #: 44407

100ohm input. Excellent condition.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Onkyo P301

Audio Proz Inv #: 57761

Phono in, 6 line level inputs, front panel in black, nice EQ. #9

SOLD  Contact Us  

Contact us about similar items or replacement parts.

Newmann PV76

Audio Proz Inv #: 44157

Up to 76dB gain in 6dB increments, selectable high pass filter at 40, 80 and 140Hz, XLR mic level inputs and XLR +4 dB outputs.

Contact Us  Contact Us  

APT Holman 1

Audio Proz Inv #: 71751

 PRE Pre-Amp board, phono, 201A board, medium gain version, not updated but works, must be adjusted for specific input impedance, 9 Condition

Contact Us  Contact Us  

APT 202A

Audio Proz Inv #: 45886

Moving coil preamp. 75ohm input impedance. Super low noise top board. Serviced and fully tested, with some capacitor updates. Excellent #9 condition.

SOLD  Contact Us  

Contact us about similar items or replacement parts.

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.


We are a very different kind of shop. To help ensure a smoother experience please read our letter about our current shop policies.

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. 

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.


Bryston 1B

Audio Proz Inv #: 943207

Make an offer. In: Tape1/Tape2/Aux/Tuner/Phono 1 and 2. Ruggedized and fixed AC wiring. Complete, intact, working unit. Cleaned controls with AG cleaner. All channels calibrate +- 1db, with a 88db noise floor. Cleaned corrosion on board, fuse, and connectors. 220 Volt operation. #8- condition

SOLD  Contact Us  

Contact us about similar items or replacement parts.

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.

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.

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.

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.

Nikko Beta 50

Audio Proz Inv #: 14480

Preamp - Stereo, modified (PS, headphone, regulator stage, tone control for better signal to noise), unit in excellent condition

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.


NAD Series 20 1020

Audio Proz Inv #: 26539

Stereo preamp, Good phono preamp, all controls and switches cleaned

SOLD  Contact Us  

Contact us about similar items or replacement parts.

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.