AM/FM Preamp (Preamp with built in Tuner). NO REMOTE. 6 db gain change at output circuit. Low noise for headphone out. Used excellent condition, modified unit for better nicer range on volume control. #9 condition
Nice, basic preamp, EQ, updated with TL075 op amp for tone controls (lower distortion, noise), did 250pf and 18k resistors on all input jacks for RFI protection, did 50pf RFI protection on phono input, revised more correct grounding for phono input, updated power supply capacitors and improved grounding, nice face, not original bass controls, # 8 + condition
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
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!
Stereo Control Amplifier. High accuracy EQ. GMN Stage volume and level control for a very high gain low noise FET gain, low noise FET Design. Audiophile phono pre MC and MM. Cleaning, glue removal, and board resoldering done. Low use #8+ condition SUPER LOW NOISE!, Condition #8+
Stereo Preamp. Tuner, Phono, CD, Aux 1, Aux 2, and Video inputs. Loudness, and low level switch. Bass and treble EQ controls. Infrasonic filter switch. #8+ condition - Minor scratches and wear on face and top cover.
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!
Top Quality Hi accuracy, very well built product. Complete service , clean and calibration. Inputs: Phono 1 and 2 , tuner, Aux1 and 2, Tape 1 and 2 (Dubbing 1>2 2>1) Level 3 modification by AP. See description here : https://www. Audioproz. Com/AP. Php?Article=95 #8+ condition Minor scuff on face panel.
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
Super Quality Preamp, Much class circuit design, (2) new upgrade quasi op amp circuit for phono section. (2) other modules (original) have been opened and re-soldered mini circuit board, double up on Mylar preamp coupling caps. Excellent Noise Floor, MC transformer installed type 8020 40ohm load. Most caps replaced in power supply (small value types)All calibrations done for preamp module D. C. Offset, new status bulbs. case and cover has few minor scuffs, Face is #9 Very low use machine #8+ condition
Fancy high preamp. Class A module design. Slimline design. Bass/treble controls. MM, MC input. Headphone out. Unit does indeed have little more clarity in over all design (subtle). Some power supply upgrades of crucial resistor and rugged resoldering. #9 condition.
Email us at sales@audioproz.com or call (617) 926-8020 for more information about ADA modifications and repairs.
Apt Holman Preamp 2
# 71499
Serial number J81E223. Level III mod, upgraded: all P. S. Caps, all audio caps, headphone op amp, phono EQ circuit. AP correctly updated unit. Condition 9
Stereo preamplifier - Gray with black knobs - Slim unit. Inputs: 2 tape (1+2) Tuner, Aux, Video, CD, Phono (MM) Outputs: 2 Preouts and Headphone (1/4" Jack). When headphones are plugged in, Pre outs are muted -Nice feature! Very nice quality basic preamp with good phone stage. Low use #9 condition
Original version, really nice lightly stropped gray face coloring with light gray purple knobs, nice look with rare and interesting version of cosmetics but still has the look of APT coloring, All Level III Audio Pro Mods, phono update, headphone mod, all audio cap all PS caps, Relay mod, Image control mod, EQ mod, Tone control mod, #9 Condition
Complete level III update, Rack face, no handle. Minor bends and dents at one rack hole. Slight bend at each side. Flat matte black face. Lettering is perfect. . SN: 2527, but has later version boards. Unit can have another face installed, call. Condition #9. See about Level III mods here. Https://www. Audioproz. Com/AP. Php?Article=95
High Quality Reference standard pre-amplifier byTom Holman. This is a stunning looking preamp with a new black pebble face panel and grey knobs- very sharp and Vinces favored look! . Complete Level III modification which includes : All power supply caps upgraded, Audio caps upgraded, relay updated, headphone amp FET spec. All modification to Phono, EQ, Tone control circuits as well as infra filter. Excellent condition #9
Vintage preamp, silver face with black inset, bass / mid / treble controls with turnover 250hz 4kHz, phono 1 / 2, tape 1/ 2, tuner, aux inputs, *back panel RCA's have been replaced (metal plate was cut to fit new RCAs), fully serviced, excellent condition, all basic service, condition #9
(1) Stereo Balanced XLR, (2) Stereo Line Inputs, (1) Stereo Line/processor, (1) Stereo Line/tape, (1) Tape out RCA's L/R Main Outputs RCS and XLR, Super Quality, NO REMOTE / NO PHONO, with photocopy of owners manual, Condition #9
Audio Pro Modified Level III, Nice low use unit , Ground mods, tone control mods, headphone amp mod, All necessary capacitors replace & phono filter, Relay cleaned & tested, RFI mods. Only minor wear on face and top cover #9- condition
Headphone out, hi-filter, montor source/ tape, left/right balance slider, bass/ mid/ treble sliders, loudness, tone mode selection. Beautiful unit in excellent functional and cosmetic quality. Better version electronics (tantlum caps). Clean face with minor signs of use. Aftermarket feet installed on bottom. #8+ Condition
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
Comes with remote. RCA & S Video inputs include: DVD, Digital RF, Digital Aux, LD, VCR, Video Aux, CD, Tape, Tuner. NO PHONO INPUT. RCA outs include: Front, Rear, Center, Subwoofer. Many Surround mode settings. 14 FM preset slots. High quality blue boards & Capacitors. Unit has many cool functions, it is recommended that interested customers research these functions online before purchase to see if this unit will fit their needs. Unit has seen very little use time, cosmetically excellent. Faceplate, covers, all controls and connectors are super clean with only minor signs of use (light surface scratching, wear/ staining from age and light use. ) #9 Condition.
Pristine cosmetics and fully functional, Audio Pro Modified level III, capacitor updates throughout all boards, relay replaced, upgraded -super clean operation, All controls and switches multistage cleaning, soldering ruggedized throughout especially any connectors and grounds. Ground mods completed, eliminate any low level buzz or DC bleed. Full calibration and mods level III, Excellent cosmetics only light scratches on top cover. #9 condition
Stereo Preamplifier. Phono, 2 tape in, 3 line inputs. Super quality built machine. High quality parts. Socketed Op Amp, OP 37 & LT 115. Controls/ connectors all cleaned, fully tested. Handles have slight metal discolor but otherwise very little signs of use/ wear. #9 condition
