Audio Proz Service and Sales

People tend to hate me when I tell them this, but really now, Behringer & Zoom (among a few others) are actually the leaders of guitar effect processing technology. I like TC electronic (which is actually I.V.L. Designs) and I can always order their stuff in for customers (TC G-Major/Minor), but nearly equivalent product can be had with the Behringer V-amp bass modeler for about $200. You will be amazed. I’m in the positi...

Q) I'm looking for a Marantz CDR 600 or a Phillips CDR 101. Do you have one or know where I might find one of these old units??

A) In all honesty I would have to strongly advise against looking for one of these machines. They were notorious for high failure rate, and parts are difficult to find. Seldom is a cost effective service possible. Philips owns Marantz and sets the policy. The only reason why a Marantz is listed h...

Local documentary director and journalist Len Edgerly stopped into our shop the other day to purchase some equipment and was impressed enough with the contrast between our style and that of the corporate audio world, that he asked if he could do an impromptu video interview with Vince. Within a few minutes the camera was rolling, and by the next morning his interview was online. Len apparantly does not mess around. See Vi...

Q) What Are Some Prices for the Loopers?

A) The EH 2880 Looper is typically $500 new. Electrix Repeater is typically $600 used to $900 new. The other looper prices should be available from any major market retailer, we simply follow current catalog prices, quotes (which are all within a few dollars of each other) and then order in for customer. To be honest I would need more info as to what exact function the looper devic...

Q) In your opinion how would these speakers work as rears in a theater system?

A) These are OK. People want them because of style appeal. Infact the speaker is a common woofer tweeter combination hidden inside an unserviceable sealed metal basket. The units I had were the better peerless dome and better CTS woofer, so they should be reliable. Others had cheaper parts. Ohm products varied tremendously with age and marketing...

Q) I am looking for the best set of vintage speakers by either KLH or AR to couple with a Macintosh receiver ca 1970s. I have some 5s which I like, but I want to add another pair. Would you recommend KLH 6s or 20s or which model for the best sound possible? Also how do you compare AR with KLH.

A) AR and KLH are very similar in many ways. Later version AR possibly have better tweeters. The real old speakers either have limi...

These CAD e70 microphones are simply amazing! Simply put, they will compete with any similar design on the market at any price. Vince has compared them at the test bench against the fanciest stuff out there, including Neumann and AKG. Since they are a higher output mic, the self noise can read slightly higher off the spec report, but the extra 4 to 6dB of output signal level easily makes up for this self noise. The e70 is...

Q) Hi some time back I purchased a pair of Electro-Voice Interface A speakers on E-bay less the equalizer. I hooked them up and they sounded fine but I seem to remember them having more bass response (I am basing this on how I remember them sounding 30 or so years ago). I finally saw another one on E-bay again last week or so but lost the bid, I have two questions: first, do you feel this unit is required for the speakers...

In Defense of Behringer The lawsuits filed against Behringer for supposed “copying” of other manufacturers’ devices are frivolous. Boss sued for copying the shape and color or a guitar stomp box, not for the design content. Behringer’s product was far superior and used modern DSP technology which Boss had not even achieved yet. Mackie also sued over the shape and color of a product. Meanwhile, many Mackie products are sol...

All good condition, freshly added to our shelves. Search in our database by product name or contact us for current availability.

42320 Speaker KRK 6000 Studio Monitors

42384 Processor Eventide H3000 D/SE - SOLD

42392 Processor Antares ATR-1a

42388 Delay Yamaha SPX990

42383 Compressor Drawmer 1960

42440 Delay Lexicon LXP-1

42382 Compressor Presonus ACP-22

42379 Compressor Presonus CL44

42380 Noise Reduction Presonus GTX44

4...

Q)I need to get one in order to transfer some tapes to a more accessible format (DVD). I am somewhat familiar with the Sony line and hoping to get an SL-HF900 only because I know it was a top of the line deck in the last run of machines.
1) Are there any servicing issues?
2) Are there other machines to consider? (I need HiFi)

A)Yes, these are rare to find and expensive if found. These machines break and when fixed, tend to...

I have to tell people this bad news all the time—the heads are glass ferrite and are impossible to find or replace (one reason why I seldom actually resell these Akai GX machines as working). I should spend time to find an appropriate retrofit, but the equalization bias is specific to these heads. So it is a difficult situation. Your only option is to send the heads to someone, maybe JRF, who can do a very special polishi...

Lately we've received plenty of emails asking about the condition of our used mics and processors. Every unit we have for sale here is the prime pickings of units we've picked up, they have all been benched, fully tested and polished. Unless otherwise explicitly noted, our mics and processors are ready to deliver stellar and reliable performance. Indeed, you can buy with confidence from Audio Pro.

For the sake of efficiency, we ask that prospective sellers have an idea of how much they would like to sell their gear for, before contacting us. This can be a range that you are comfortable with, a target price, and/or a minimum price. This way we can make sure we don't waste any of your time if you need to get more than we can pay.

eBay is a good starting point to determine price, as it's a broad marketplace that we o...

We don't have an online shopping cart yet, so we currently process payments through PayPal. If you're interested in a part or machine you've found on our site, just click the "Contact Us" link that's in the far right column of the listing. This will start an e-mail with the item ID number/name pre-filled in the subject line. In the body of the e-mail, feel free to ask us any questions you might have, and include your zip ...

The boards are adapted to as close of input impedance match as possible when ordered (and noted on website). Many boards 210, 201A 202 etc. are very similar but differ in subtle ways because M.C. cartridge designs (even same models) varied in performance, especially in low frequency "equalization" and output level. We at APT tried to keep up with this matter and attempted to calibrate each card to within +/- 1db at 50hz (...

Q) I have a problem with a Technics SV-DA10. It plays well, but is unable to rewind (except when the pinchroller is engaged, like when using the jog/shuttle). Would you have an idea?

A) The problem may be:
1. The brake shoe for either geared tape hub is loose, falling appart and interfering with the tape hub. I have simply replaced these with a proper sized piece of very fine felt or soft cardboard glued on with a tiny b...

Q) I am interested in the B2 Pro. I want to create a U87 clone with my original K87 capsule. Can I get a good U87 clone with your mod and changing the stock capsule to my K87 capsule?

A) Sorry, I don't know ...it won't be the same, can't be ! In fact some china capsules are actually better ! The real issue is the bias volts on the capsule , internal "meg ohm" load & high frequency trim capacitor as well as gain circuit ...

Wow, new cutting edge construction designed ribbon mics are now here. Although the wave of quality, large plate condenser mics has saturated the market and for many recordists who have an open mind, great benefits of cost to performance are welcome. Ribbon mics however will not be easy to make inexpensively and correctly. This is because the design criteria for ribbons are ironically more archaic and tough to build with c...

I have written this letter many times before, here it goes. Bellari 282 had two ways it could be releases to public and operated. One way is as a true volume gain limiter, as it looks at signal after the compressor circuit making the compressor gain ride it’s own “Audio tracking level”. This can really, make the audio squashed because the threshold control actually works like old school design. It advances CCW into low si...

Q) I recently bought a vintage Scott 388-B receiver that plays very well except for the FM I can't get the multiplex board to light the stereo light. The voltages seem ok at the test points on the board. Can you help? Thanks.

A) The unit needs a real, complete service. Unfortunately, units of this age will require many capacitors throughout the unit to be replaced, this is a certainty, and with a proper tuner alignment ma...

I'll try to make it quick (haha). The simple fact is almost all of these new supposed monitor speakers are Chinese pre-designed platform products with different cosmetics for different markets and price points. I see the same product at $300, $600, or $900 & they all suffer from the same issues: false bass tuning (humpy, bumpy, boxy, etc.) and incorrect and simple crossovers into tweeters to make them sound zippy, forward...

We get many letters and phone calls asking about certain high dollar audiophile gear, which all basically boil down to - does this unit do what they claim it does?

Many manufacturers make remarkable claims of amazing fidelity. Are these electronic designs capable of revealing or creating more lifelike imaging or depth of detail when amplifying pre-recorded music? Does the use of super special capacitors, wiring, and conn...

To be honest, although I play guitar, many guitars and many variations of pickups and strings which make big differences no doubt, a bigger issue is that all these fancy amps really share very common similar designs (ie the tube circuits actually are more similar than truly unique to each design). Really what is different (what you hear is different) are simple different equalization (like having a little 7 band equalizer...

This is a letter to inform our past and future customers about our shop , its work efforts, scheduling and general policies. First off, please remember we are a small specialty shop. We would like to explain a few things about recent, unavoidable but important changes in operation.

Our shop is suffering somewhat due to over-worked demand for our always best work efforts, problems with consistent help needs, training new e...

Q) I am trying to find a pinch roller for my Tascam 244, so far without success. One fellow out in California may have them, but it will not be for another sixty days minimum. Might you have one available?

A) We request you sen us the old frame, which I rebuild carefully for $28 plus return shipping. I own a 244 myself and rollers are slightly special (high speed use, wow and flutter). Even nice looking rollers the rubber...

Q) How many watts is the JVC RX 550 V?

A) About 40 to 50 watts of average power. The amplifier is infact designed like Adcom or other real HiFi amps. I have sold a lot of JVC product. It is a very reliable era of product, but it is important to get low use machines so that buttons and switches are nice. Our product is clean and has low use time. That is why we call it in #9 or #8 condition. These amplifiers were simple "hi...

Q) Would like to hear your best price on the American R331 microphone you have listed.

A) Actually, I don't have any left in stock now but had many previously here. Be aware now so many better, correct, lower noise, working ribbon microphones for less money now exist. I would not recommend the R331 now for quality of performance, although I do have some original boxes for vintage collectors who indeed pay a serious premium...

Concerning transformer use. Interesting, wonderful but brutally simple transformer designs, in many vintage products do create a nice, slightly “warm” sonic color but there are modern products which can do the same sound trick but without the high expense and use of rare parts. First be aware of the +24dbm maximum operating level (transformers or sound state) used in real pro signal level designs do not mate perfectly wit...

Q) Do you sell aftermarket Electrix Repeater Power Supplies?

A) Yes, infact others are asking for these as well. Incredibly to do it with nice cable, box, and supply it will be $140. I need them too, but now I can only fabricate from parts and pieces. I need the somewhat special cable from existing supplies. I have also opened and fixed original supplies. This is $88 to do (small board, some special parts to fit "switching...

It seems people are constantly asking about modifying machines by changing out op amps. Most recently on a TNE 7000 Noise Reduction unit which we do modify (see Services section) but not by changing out the op amps for more updated, better paper-rated versions. Ironically, “better” op amps will actually work worse in the circuit due to the need for correct DC offset and time phase, delay required at 4 stage all pass filte...

Chinese mics (and their boutique relabeled versions) almost all suffer from the same problems. In fact, AKG, Neumann, and many other big name manufacturers do not design their own internal power supplies, shielding, grounding, and RFI protection well enough. Now with today's super sensitive mic elements with high gain circuitry, and more radio frequencies emanating from computers and cell phones, such shortcomings can app...

The butyl used for textile surround restoring that has been recommended online appears to be somewhat problematic. First being that it is sticky, too sticky in my opinion – it’s attracting debris of any kind and accumulating on the surround. Large debris might actually cause some buzzing when vibrated. Another issue is the butyl treatment if allowed to get on the edge of textile where the cone is glued to the textile or t...

Q) Shielding is crappy. I hear radio all the time. Is there anything I can do to improve this?

A) It’s not exactly the shielding. Some studios have troubles, some not. The problem is endemic to most powered monitors due to difficult ground, 120v ground loops and troublesome incorrect balanced cables and other situations between devices. It’s not the “shielding” although it could help to isolate and specifically shield the...

The DBX Sub Harmonic Synthesizer was truly an amazing unit, though they are getting hard to find. I owned one years ago, then used an ‘expounder’. Did 4 bands of dynamic EQ as well. Clever auto filter effect and 4 bands of parametric EQ. Now I use a Behringer DEQ-2496 multiband adjustable dynamic EQ, compressor or expander and 5 band digital parametric and 11 band EQ, and real time high sensitivity spectrum analyzer and d...

Q) What is different about the dbx 3bx pro... is it the ds series?

A) DBX expanders are all conceptually the same. User controlled capability of creating more dynamics and lessening the noise floor (of vinyl and tape) by "expanding" the music's dynamic range, leaving the noise floor further down in level. Old 3bx, big knobs and LED's in 2 rack space box, are discreet circuit 3 bands of VCA to separately improve bass, middl...

So now, onto a most delicate subject: the psychology of hearing. Keep in mind that I have been speaking to customers for the past 25 years. All the way back to cassette decks, reel to reels, turntables, CD and DVD players, to modern computer recording systems. I think there is a tremendous ambiguity to the question 'what truly is the best sound?' What is the standard reference playback device? Who has the book on real con...

Q) How does the ADA MP1 Classic model compare to the modded MP1's? Do you repair them? Is the ADA foot controller the way to go with these?

A) The Modified ADA are changed to sound less "metal" on too many programs and more control is available to enhance regular electric and acoustic guitar sounds, but it still can do the “buzz saw” metal sound no problem. The MP1 is a device which obviously intends to use the tubes to c...

Q) Hi there, I was wondering if you guys mod the single channel Bellari MP 110? If you do, how much? I would like to replace the OP AmP and the transformer. Which op amp and transformer would you put in there? Please let me know and thank you for your time.

A) We can modify the Bellari MP 110, but the specific mod you are asking for would not be something we would recommend. There would not be any obvious change in sound, ...

Please take a minute to read these basic guidelines, as we are a small shop and do things a little differently than some larger corporate chain-marketing-type businesses. We can serve you better by ensuring that the following is understood.

** Buying from Audio Pro: **
We carry a wide variety of audio equipment and parts. While we strive to keep our online database up-to-date, it is not automated and does not always refle...

Q) What mods do you do to the Behringer EX1000 and Edison? What is the main differences between the ex1000 and ex1200? I used to own the ex1000 an am interested in getting one or the 1200. Thank you in advance for answering this.

A) I modify the EX1, to be honest I seldom see the EX1000 or 1200, but I must assume it’s a similar machine with similar mod requirements. It’s a good design except the LED and it’s circuits which...

There is an old expression which might be appropriate here but not necessarily truly my philosophy “don’t say anything unless you can say something nice”. Ironically this applies to friends and acquaintances but when talking about audio, electronics, etc. saying something bad, whether true or not can get a lot of people irked or worse a lawsuit from a megalomaniac electronics company. This is a reason why a negative criti...

Q) Between the Symetrix 522 and a pair of 501s, which would be better for vocals, guitars, and bass guitar? Why such a wide price range for the 501s you have for sale? Can the 501s you have for sale be master-slaved for stereo?

A) These compressors are almost the same but the 501 will have more adjustment controls and range over the 522. Although sharing the same VCA, the 522 does not have as sophisticated RMS circuit (whi...

A Letter from the Owner Vince Naeve

People have been commenting about some chatter being posted on the web. A long time friend and customer has recently made me aware of this. As usual, in this world of sound bytes and quick words taken out of context, I feel people have read me incorrectly, or more over, have not understood a deeper realization about the recording or Hi-Fi industry and the equipment they transact.

To pre...

Q) Hello, I too have one of these DBX DX5's. I love it but did not know it had so much value. I see a lot of recording studios seem to have these. Why are they considered to be so valuable?

A) I try to answer all questions. Obviously our website info makes it clear I am a no nonsense kinda guy (to the best of my abilities) but have a passion for music, sound and what and how it is created and transmitted.

Once upon a time ...

Here is your chance to purchase or partner with a well established audio electronic shop in the Boston area. Audio Pro in Watertown, MA has been in business for almost 25 years repairing and selling audio electronic equipment. We reside in a large rented space with an extremely spacious basement. There are 3 service benches complete with test equipment and tools with two desks for office use totaling 2400 square feet. The...

Are you a consumer oriented audio electronics technician living in the Boston, MA area? If so, we would like to talk to you about an opportunity as a technician in our shop. We are looking for someone who is passionate about Hi-Fi and pro audio, and has a vast knowledge of audio electronics, from reel to reel tape recorders to digital effects processors, from tubes to transistors, and everything in between. We don't look ...

(a letter to a customer)

Thank you for your inquiry on the Edison EX1

The Edison is an audio processing device designed to enhance, correct, or remix stereo program material of any type or from any format. It is especially useful and shows it’s capabilities astonishingly on vintage music, or most music which came before the digital era.

First off it is truly a stereo processing device which operates purely in the analog d...

By Vince (Shop Owner)

To start off, I would like to say that I am a technically knowledgeable person (as opposed to purely sales oriented imagination) who has been working with pro and consumer equipment for over 25 years. I have worked with engineers of audio equipment, I have headed service departments for hifi companies such as HH Scott, Apt, KLH, and have been running an electronic repair/sales shop for about 20+ year...

I know that many people will debate me when I tell them that I have encountered far too many "supposed" esoteric, expensive, fancy cabinet design speakers and gimmicky speaker designs to be extremely lacking in regards to phase accuracy, or at least having reasonably wide frequency response or dynamic linearity to be accurate enough to honestly judge the “supposed” attributes of special capacitors, resistors, wire, or wha...

Q) I have a pair of ads 810 series 2 a tweeter went out and I got a replacement. Not the stock 3/4 inch softdome though. Do you have any of those available? And I have a curiosity mabe you wouldnt mind answering this for me.(I know its personal preference) If you had only two choices between a/d/s 810 & Polk audio monitor 10 which would you pick? Kinda like Mustang vs Camaro, apples against oranges.

A) I've owned ADS which...

Q) I found a strange old pair of speakers at the dump one day about a year ago. Brought them home, dusted them off, spent about a month killing mildew... They are Walsh 2 speakers, with a Huge crossover in the depths of the cabinet, and a removable "Capsule" containing the drivers. They sounded pretty darn good at first but now the tweeters, buried deep inside the capsule, are beginning to sound fuzzy and the mids need to...

Q) First: I like your web site and I like that it is important to you that you express yourself. When running my own video production biz, once upon a time, I had many of the same feelings about quality and customer relations, etc.. I wish I was the guy who could work with you. I recently puchased a used Odyssey Khatago ampifier. Got a very nice deal. This replaced an Adcom 535. My current Speakers are old (re-edged) Bost...

Q) Would opting for different tubes enhance the mods you make on the Behringer T1952 (Tube Compressor) and which tubes would you recommend?

A) Different tubes changing the sound? Yes and no. Yes a 12AT7 or AU7 would perform differently, but my research (after changing, modifying, listening, testing) shows that the circuit changes greatly over shadow any subtle changes by exchanging the tube and then recalibrating. In fact ...

The service and repair of our customers’ equipment is our most important labor, therefore we are not able to fulfill every photo request we receive (nor would a photo qualify what’s vital here, the internal components!). AudioPro has been in this business for better than thirty years, we have a tremendous reputation, and we take great care to accurately describe the mechanical and cosmetic condition of all items. We rate ...

I have a love/hate relationship with these Nakamichi models. These units unfortunately suffer in performance with age and use. They use a sophisticated and complicated power supply and computer chip, but the audio circuitry is very basic, standard Japanese design used in many better quality designs like Adcom, Rotel, JVC, Denon, and Yamaha. Some people are under the impression that it’s a special class A design or STASIS ...

Q) Just found your site and I hope you won't mind answering a question for a real neophyte when it comes to audio.

I have a real thing for the sound of vintage, tube stereos. I first had the experiece of hearing my favorite blue note and verve lps played on a friend's father's system. He's gone now, but I remember being blown away by the warm, lush sound. All I can remember is him saying that he revered the dynaco st-70 ...

Q) I am running an old solid state receiver an older turntable have been playing much more acoustic music in the last year. A friend who is a real high-end tube nut says if I want to hear vinyl played back well, I need to consider at least running a tube pre-amp. He had a couple of recommendations of pre's that he believes are well designed for turntables. As I found, there is a 'pre-amp in' input pair on the back of the ...

Q) What do you think of the Nikko Beta 30 Preamp?

A) The truth is any reasonably well designed preamp, regardless of what op amps or circuitry is in it will sound OK or excellent or terrible depending upon the expectations of the consumer. This preamp as well as many other better designed Japanese preamps were remarkable if careful gain staging to keep the noise down and quality components, switches, capacitors, etc. were ...

Q) I just purchased a Pioneer rt-1050 reel to reel tape deck. I've found that the speed is very unstable. Is this a common problem with this unit and can it be caused by non-manufacturer power chord which this one came with?

A) No. These are great machines but obviously they are 35 years old now. The problem is the unit is in need of maintenance. (possibly new drive belt, oil of motor and mechanism, the speed switch itself...

Q) Can you please list for me the equipment you use when performing an FM alignment?

A) Well, I have lots of test equipment. Sountech, Leader, Tektronix, etc. but if you’re asking if I’m qualified by the equipment I own that would be misleading. Truth is, tuner design is somewhat technical and mystic art. Often times I alter tuners to improve the tuner shielding, grounding, stub tune the 300 Ohm Balun Antennae matcher and ...

Q) Would be so kind to tell me which machine is better for recording and listening tapes? Revox B77 or Teac A3440?

A) Yes, one of my favorite kinds of questions, but strangely, a tough one to answer. Here’s the strange truth. Both decks at this age would need cleaning and calibration. If basic service is done, the Teac would win out mechanically, but not by much. Yet the Revox would be the better sonically, but not by mu...

Besides being an avid collector of audio equipment, Vince has also built up a unique and interesting assortment of collectibles of all varieties. We thought it might be interesting to start including some of these on our website for you to peruse. Variety is after all the spice of life, is it not?