Top quality phono preamp with gain control and cartridge loading select. Includes DC power supply, New in box
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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
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
MM Phono preamp, updated power supply, replaced power cord, checked for noise - floor is excellent, Condition #9
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.
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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.
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!
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Basic preamp. Top quality phono (with correct ground layout)! Audiophile tone controls, only accent extreme high and low. 5 inputs, bad obvious light scratch at switch, #8- condition.
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Receiver converted into PREAMP. Black faceplate. Phono, CD, Video 1, Video 2, Tape 1, and Tape 2 inputs. 10 tuner presets. Built on (non-original) volume knob, with cut hole for LED indicator. #7 condition
Pebble Black Finish, various available. One (1) in #9 Condition- $68. Six (6) more available in various conditions, all good with no major damage, approximate #8+ condition -$46.
Basic phono to line level w/ RIAA equalization, RCA / 1/4" TRS output (line level), 12v DC power supply included, Small and compact (4"x2.75"x1.25"h), Original box and manual, Used in Excellent condition #9
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.
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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.
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+
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Control Amp. (2) Phono in with selectable MC/MM, 3 position cartridge loading switch, and 3 position gain selector. Tuner, CD, Aux 1 and 2 inputs. (2) Tape loops, and (2) set main RCA outputs. (Has some DIN connectors for Tape, CD, Tuner). Complete cleaning and serviced by AP. No remote, Missing (2) function selector gap covers. #8 condition. Missing (2) Function selector gap covers for CD and Tuner
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!
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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
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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
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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
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We know you have many options for purchasing audio equipment and parts, and we truly appreciate your business. We strive to offer good products at competitive prices. While we can't always match the prices of one isolated reseller, we make up for it by carefully selecting, testing, and finding unique and special rare parts, and we are here for the long run. We guarantee everything we sell and we hope it helps you to enjoy a great listening experience.
phono preamplifier, variable preamp gain, RCA outputs, new in box, OUR RECOMMENDED PHONO PREAMPLIFIER! #10 condition
Set for 100 ohm impedance, but can be changed per customer request. (15db gain modified). All caps updated / recapped, noise check, EQ check.OK #9 condition
Mc pre-amp board. Complete. Good condition. Tested and working. Has original caps. #9
Pre amplifier, superior design, gunmetal gray, rack mount with rack handles, excellent phono stage, MM + moving coil class A fet design, eq circuit with turnovers (3), (bass 50/120/250 treble 3K/6K/12K), external processor (EPL loop), cosmetics excellent, low use, all control switches cleaned, #9
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Set for 100Ω impedance but this version can be reset to as low as 20Ω, low noise spec, no capacitor update but unit performs perfect, low use, QC check, #9
Soft black matte finish rack faceplate. Chrome handles. Unit also has all Burr Brown. SN# 6254. OPA 2134. Replaced in all line level circuits. Results in a 2db noise floor improvement but really the unit has a 93db to 96db noise with standard A.P. mod. Some light fingernail scratches on face. Unit 3 position high frequency EQ switch, middle position is an analogue EQ for CD. An extremely subtle audio improvement was noticed, but only under the the most critical and best headphone use. #8+ condition
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We offer expert time-saving advice on repairing many types of home and studio equipment, as well as consulting for product and recording issues, at a fair and reasonable cost. For complex matters, we sometimes must charge a small technical fee. If we can help solve your repair problem or technical conundrum, give us a call. (617)926-8020.
Stereophonic Preamplifier. SN: AK2903. Aux, Tuner, Phono 1 & 2, Mic, and Tape HD Inputs. R/L Controls for both Bass and treble, headphones, and tape in/out jacks. This unit is fully serviced and tested. One capacitor added to improve power supply. Cleaned all controls, switches, jacks, tightened connectors, checked phono noise, and a 2nd switch cleaning. Includes all original packaging, owner's manuals, factory harmonic distortion test graph, cabinet available also. #9 condition
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USB dual Pre. 2 channel. Computer interface. Project series. 10 condition. New.
