Home Products Services Custom Mods Educational AP Mix

Featured Items ]

Amplifiers ]
Amplifier Parts ]
Bargain Bin ]
Cable/Patchbay ]
Cassettes ]
Cassette Parts ]
CD ]
CD Parts ]
Compressors ]
Crossovers ]
DATs ]
Delay/Reverb ]
Equalizers ]
Foot Pedals ]
Guitar/Bass ]
Headphones ]
IC Chips ]
Keyboards/Synths ]
Literature ]
Meters ]
Microphones ]
Mic Preamps ]
Miscellaneous ]
Mixers ]
Multitracks ]
Noise Reduction ]
Parts/Hobbyist ]
Power Supplies ]
Portables ]
Preamps ]
Preamp Parts ]
Processors ]
Racks/Cases ]
Receivers ]
Receiver Parts ]
Recording Media ]
Records ]
Reel to Reel ]
Reel to Reel Parts ]
Remote Controls ]
Speakers ]
Speaker Parts ]
Test Equipment ]
Transformers ]
Tubes ]
Tuners ]
Turntables ]
Turntable Parts ]
Vintage ]


Home ]
Products ]
Services ]
Modifications ]
Educational ]
AP_Mix ]
Contact Info ]


Service & Repair ]
Modifications ]
Rentals ]
Consultation ]
Installations ]


Educational ]
Ask Vince ]
Shipping Guidelines ]

AP Mix

AP Mix Contents ]
Vince Collectible ]
Useful Links ]
Testimonials ]


Featured Items

Tuesday, February 9th, 2016  
Search For:     Site   Products   Services   Educational  
Full Products Listings By Category

Amplifiers ] Cable/Patchbay ] Cassette/DAT ] Cassette Parts ] CD ] Compressors ] Crossovers ] Delay/Reverb ] Equalizers ] Foot Pedals ] Guitar/Bass ] Headphones ] Keyboards/Synthesizers ] Meters ] Microphones ] Miscellaneous ] Mixers ] Literature ] Noise Reduction ] Parts/Hobbyist ] Power Supplies ] Portables ] Preamps ] Processors ] Racks/Cases ] Receivers ] Records ] Reel to Reel ] Reel to Reel Parts ] Remotes ] Speakers ] Test Equipment ] Transformers ] Tubes ] Turntables ] Turntable Parts ] TV/VCR/DVD ] Vintage ]

Featured Items - Updated November 2013


Phase Linear 4000 Preamp

Phono 1/2, aux, tape 1/2 ins. Joystick balance control. L/R bass and treble controls. Switches for turnover frequencies. 90% of audio caps replaced with higher-quality parts, board connections ruggedized with improved soldering. Modified low noise floor with some Carver documented updates and Audio Pro updates, modified with better detent volume control. Unit has low use time. Some back panel connectors have been replaced with similar, better quality connectors. Face and all mechanical parts in 9/10 condition. Designed to expand or uncompress the sonics of recorded material; in audio parlance it is called dynamic headroom. The 4000 has the capability of controlling up to six components: a tuner, two tape decks, two turntables and an auxilliary. It has three switched and three unswitched AC plugs. The 4000 was manufactured from 1973 to 1977. It is still highly sought after today. Specifications: Frequency response: 20Hz to 20kHz Total harmonic distortion: 0.25% Gain: 65dB (MM), 15dB (line) Signal to noise ratio: 72dB (MM), 83dB (line) Semiconductors: 45 x transistors, 9 x IC, 57 x diodes, 2 x zener regulators, 2 x LED Dimensions: 19 x 7 x 10 inches Weight: 18lbs

(-- SOLD --) (Contact Us)

McIntosh Mr77 FM Tuner - New Lower Price November 2013

The MR77 is one of the truly great McIntosh tuners. Produced from 1970-1978, the MR77 was designed by Richard Modafferi. The MR77 is essentially an MR78 without the variable selectivity - same designer, specs, etc. Soundwise in comaprison to the MR78 there is little sonic difference between them on any station with sufficient signal strength. The MR78 alternate channel selectivity was better but, this is at the expense of frequency bandwidth. Hence there is a tradeoff. The MR77 tuning is smooth. The sound is liquid. It is easy to forget with a good classical station that it is a tuner that one is listening to. Rich, tight bass, balanced detailed midrange and very detailed high-end. Like all McIntosh components it was designed and built to last a lifetime. Sensitivity 2uV for 35dB of quieting. Response 20-15kHz (+1 -1dB). Distortion 0.2% in stereo. Capture ratio .25 dB detector only, 2.5dB complete tuner. Image rejection: 100dB at 90 MHz, 90 dB at 105 MHz IHF. S/N 75dB. Separation 40dB@1kHz. Volume with on-off switch. Tuning ctrl. Signal strength and tuning meters. MPX indicator. Multipath indicator. BACK PANEL: Audio out 2.5V variable and 1V fixed. 300 or 75 ohm fm cable input. Scope outputs. Panloc mounting. In summary, this tuner is about sound quality. The designer who created the MR77 and MR 78 was a definite music lover. Unit is in 9+ condition. Low use and has been serviced. Alignments by Audio Pro. Unit has 1 or 2 tiny scratches at corners. Perfect glass. Connectors at back panel and chassis have no rust spots. Truly a museum quality collectors condition unit.

(-- SOLD --) (Contact Us)

KEF RDM2 SP3254 Monitors

Audiophile version mini monitor. 6" coaxial driver, red and orange oak cabinet with glass tops. Excellent #9 condition: all parts tested and perfect, grills and driver all excellent.

(-- SOLD --) (Contact Us)

Peavey Classic Guitar Amp

Peavey Classic Guitar Amp with Manual. W1 Footswitch assembly for tremelo and reverb. 4 Input channels. 2 volume (bright and normal). Bass, Mid, Treble, Reverb (depth and rate) knobs. Master Volume. Dual 12" Woofers. Soft cone drivers (original Jenson + Alnilco type drivers). New 6L6 tubes. All serviced and cleaned. Nice lead/rhythm guitar sound. Excellent cosmetic and mechanical condition. Awesome tube amp for short money!

$400 (Contact Us)

Martin Logan Script Wall Mount Electrostatic Speakers - New Low Price November 2013

Wall mount electrostatic speaker. 41" tall with mounting to wall bracket. Black with black metal grills. Sweep tested all panels and woofers good. Original box, packing, manual and two AC cords. 9/10 Condition. "We were stunned by the sound produced by the little Scripts! On all types of program material our latest creation reproduced sound with the superior immediacy and clarity that we have always demanded from our electrostatic technology. Suddenly, we realized that this new creation could add high resolution electrostatic sound to any room or application. The Script is matte black. It is configured for single-wire stereo operation."

$900 - New Lower Price (Contact Us)

Harmon Kardon Citation II Power Amplifier

Claimed by H-K to be the world's first ultra-wide bandwidth tube power amplifier. Designed from a professional sound engineers perspective by Stewart Hegeman, the Citation II featured a very high output (60 watts per channel), low distortion and an extremely high bandwidth (at 20W: 18 Hz to 60,000 Hz +0, /– 1.0 dB ). Weighing 70 pounds (almost 32 kg), this power amplifier looked good enough to eat with its chocolate coloured transformers and golden chassis.
The circuit consisted of a pentode input stage, followed by a pair 12BY7 video pentodes as a differential phase splitter (the video pentode supplied a bandwidth of well over a megahertz in the input stage). The output stage utilised a pair of KT88's for each channel, each valve having its own bias control as well as an AC balance control. A small meter at the rear of the chassis was provided for measuring bias and AC balance. Three feedback loops were incorporated, giving 32 db of overall feedback with unconditional stability.
The output transformers were superb, built by the Freed company in New York. Huge, well-potted units, they boasted extremely wide response characteristics with leakage inductance kept to an absolute minimum. Only the highest grade core materials available were used, which, lowered the effect of core distortion to a region well below the limit of human hearing. With feedback, the Citation II transformers were capable of high frequency response up to 270,000 cycles! The power supply consisted of four silicon diode rectifiers, filter choke, heavy duty electrolytic capacitors and a large, potted power transformer (also made by Freed).
Our Unit has seen low use and known to be in storage most of it's history. Some amateur service work was done but only to attempt repair of one filter cap. We have corrected this as well as did add-on "helper" caps to boost filter cap rating which lowers noise floor and improves stability of all voltage vintage new old stock match. New GE BY7A's are installed (with a spare) and new National N.O.S. 4 KT88's (with one spare) are installed. Unit has seen very low use time, maybe a few years, but again new tubes are installed.

(-- SOLD --) (Contact Us)

Custom Audioproz (Sonic) Guitar Cabinet

Custom Audioproz Guitar Cabinet. Two speaker, Celestion 12" and 8 intentionally unmatched speakers in open back cabinet. With variable dampening and phase control. Carpet covered cabinet, in #9 condition. Excellent guitar cab for electric and acoustic cab. Engineering sample

$290 (Contact Us)

Vintage KEYSTONE Belmont K161 16MM Film Projector

Vintage KEYSTONE Belmont K161 16MM Film Projector. The approximate manufacturing date is early 50's, and it is in excellent cosmetic (no discoloration on surface) and working vintage condition (both original bulbs & working great). It features a film splicer, operator light, still picture mode, take up real, room lamp plug, 7 amp motor, and Keystone Magna-Scope f/1.6 16mm lens. Serial Number #71064. Comes in a handy carrying case, with some wear, but in good shape for 50 + years old. Includes original power cord.
This machines shipping weight is approximately 25 pounds.
Keystone Mfg. Co., Boston, USA (since 1919) began to sell their equipment through Paramount Mfg. Co, Warren Mfg. Co. and Sears Roebuck. Keystone was bought out in 1965 by Berkey. Subsequently in 1991 Keystone stock and brand names were bought by Concord Camera Corp. Avenel, NY, USA.

$125 (Contact Us)


We do not price our units outright due to the fact that a large part of what we do at Audioproz is service, repair, and modify equipment to meet your specific needs. We can quote you prices as is, but often times certain service, calibration, or modifications can be done which will greatly enhance the unit and/or increase it's reliability. Therefore the prices are usually flexible according to the final level of service decided upon. On new items we will generally match prices you find from a legitimate dealer of the product.

If an item is not listed in our inventory, it does not necessarily mean we do not have it. There is a fair amount of equipment unlisted here which either has not yet been updated on our website listing, or is on hold for ebay auctions, craigslist, etc... If there is a specific piece of equipment you are looking for but do not see it please inquire here. We just may have it, be able to order it, or refer you to someone who has it.

Contact Information

All business at Audio Pro is currently by appointment only.
We're a very small and very busy shop, so please don't just drop in - call first to schedule an appointment, whether you're interested in service, rentals, consultations, or buying advice. Help us help you!

Phone: 617-926-8020
FAX: 617-926-8707
Postal address: 779 Mt. Auburn St., Watertown, MA 02472
Electronic mail: sales@audioproz.com

Our hours are:

Monday (12 noon - 6pm),
Tuesday by appointment only,
Wednesday through Friday (11am - 7pm),
and Saturday from (11am - 3pm)
We are closed on Sundays.

** Employment Opportunity - Technician Needed (2015-04-06) ** We are currently looking for a Technician, with experience in Audio. Inquire Here or call us directly for more details.

** Shipping Guidelines Update (2015-04-06) **
Please do not ship any packages to us using the Fed Ex Home Delivery Service , the packages will not arrive. They only attempt to deliver during our off hours and do not leave tags. We have tried several times to remedy the situation but they seem to have an unusually hard time with the concept. For more details about our shipping policies Read Our Shipping Guidelines Here or call us directly.

** Return Policy: **
Please make sure the part # in our inventory is exactly the one you want. The manufacturers made many variations of similer parts. If you are in doubt, it is best to attach a photo of exactly what you need.

** Condition of Audioproz items: **
Unless described otherwise in the item listing, all items have been cleaned, serviced, and tested for correct functionality on a professional test bench. Items listed as parts are sold as is.

Featured Items

Tuesday, February 9th, 2016  
Home Products Services Custom Mods Educational AP Mix