# PPI Art A200 recondition / advice



## swampwader (Apr 2, 2011)

Hello to all,
Kind of a long story but will try to keep post as brief as possible. A close friend of mine passed unexpectedly in late October 2011. About a week ago his widow gave me a Precision Power A200 amplifier that she had found packed away in the garage. I would like to be able to use the amp to power a pair of 6 1/2 components in my wife's car. 
I'm thinking that it would be wise to have an experienced amp tech look over the internals / recondition as needed prior to installation. I'm looking to have anything broken (or marginal) internally repaired / replaced. The amplifier (as far as I know) does not need repaired - I guess what I'm looking at would be more of a restoration project. I understand that the amplifier isn't worth a whole lot but it does hold a lot of sentimental value to me. 
I'm looking for some recommendations on someone that you would trust with such an endeavor. I live in a rural area (the only repair shops around here work on combines!) so there are no local options available (to my knowledge) 
Thanks for your help...


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## duro78 (Dec 24, 2011)

There's a huge Ppi art restoration thread underneath this ine

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## swampwader (Apr 2, 2011)

Unfortunately the author of that thread isn't divulging any information about his tech at this time.

_"Turns out my tech is also the best of the best for other old school amps and many of today's high end treasures.
Now, I apologize for not explaining further, but The Stig (alias) has asked me not to tell.
Hopefully in the future, I will be able to state the process I used to actually locate my tech but it would give away The Stig's identity."_

I'd love to have "The Stig" work his magic on my amp, though! Any other suggestions?


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## duro78 (Dec 24, 2011)

There's a tech by the name of Aaron from envision I believe. Unfortunately there's only a handful of reputable amp repair techs. If that wasn't bad enough finding someone to fix old school and high end amps is even harder. I guess you have to ask yourself if it would be easier and cheaper finding a new one in good condition

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## swampwader (Apr 2, 2011)

duro78 - thanks for the info - I have contact info for a couple techs (Aaron is one of them) that I will be getting in touch with - thanks again for the information.


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## duro78 (Dec 24, 2011)

No problem sir, I hope everything works out for you. Also check out Chris at dbr, not sure he works on that particular amp but he's one of the best in the business. 

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## Darth SQ (Sep 17, 2010)

DBR no longer works on the old stuff and Aaron at Envision is not taking in any additional repair work.

I know it sucks, but it is what it is.

Bret
PPI-ART COLLECTOR


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## Darth SQ (Sep 17, 2010)

Here's a message from The Stig regarding the problem of finding a good tech to fix old school amps:

I wish I had a easy answer for SWAMPWADER, but I currently have 22 car amps and 6 EQ's waiting. Being a one man operation I tend to get backed up easily with amp restorations. I know that there is a huge market for my services but I am just one person. And if I let everyone send me there gear I would have to buy or rent storage for all the vintage amps out there that folks want brought back to "Like New or Better" operation. 
The fact is that none of this gear was meant to last for ever, no matter how well designed it might have been. And any restoration takes a lot longer then a standard repair on newer gear do. < hence why so many shops decline offers to work on vintage gear, they know it will be a lengthy repair process in most cases. lots of parts and time without exception>.

RESTORATION: Requires at best a lot of component replacement to happen to be any good, especially expendable component like electrolytic caps which don't age so well. Newer components are better made and to higher tolerances than those that were available when vintage gear was built so things tend to get real deep real fast. So the average tech can get buried real quickly with hard engineering mathematics to make things work like they're supposed to with newer components.

I had hoped that all the details I allowed PPI Art Collector to post would spur other tech's to take on the initiative to do it right. But alas I think the day to day schedules of most other tech's are too rigidly administered to allow them the proper professional luxury to do the complete job at hand " Like It Was Their Own Gear". The latter part is also hard to find since it isn't taught by colleges and is not on the standard agenda of most business's.

When I open up a person,s gear on my bench, I see myself owning this exact same piece of gear. I ask myself how far would I go to bring it back to life. And the answer is always the same; as far as it's needed to be "Just Like New or Better". This is what I would expect from any service person, and I get disappointed a lot when I see how others treat my property. Like my car for example. I watch any mechanic working on it. I know better then most what is needed when I need services of any kind. So I watch any one providing me services to make sure I'm just not another PITA for their work day.

Enthusiasm: 
Either you got it for what you do or you don't. I have seen other tech's grab work and treat it like an indestructible piece of ugly steel. Bend it here and twist it there, and slam it down on the bench like a sack of potatoes. They are rushed and constrained by a schedule to finish as much work as fast as possible, so they can fart off the rest of the day. Or they just hate what they do for a living. Either way none of this is any good for you the client.
For me this is never the case as I have work lined up till next month. So to rush is to invite mistakes that would slow me down even more then my current work load. I even wrap each and every amp in my shop in cotton towels or bubble wrap when I finish my work on them to protect them. I do this to also help protect the finsih of the amps as in most cases I have taken time to clean the powder coating as much as possible and treat them to prevent future marks and scuffs to their finish while they wait to be picked up or shipped. Oh and I double box ALL my amps being shipped. it costs me more both in time and materials but this is what I would want it if was "MY GEAR".


WORK LOAD: 
I personally ship all my own gear out, and I receive all the incoming gear also. I talk at any length necessary to a client so we both are on the same page all the way through the restoration process. Then I do all the work and advise the client all the way through the process until it is completed and tested. And in PPI Art Collector's case, I sent detailed test results to post in his thread along with photo's of the work being performed. Oh and I return all replaced parts to all my clients, its state law where I live. All this takes time, and professional effort. Most tech's don't have either of these nowadays.

The business is what it is, and the only thing I can do to improve this situation is to do "my work" as if it was "my own gear", and "as extreme as needed to be absolutely correct in every way". I feel bad that many of your forum members don't feel that they can find this in their search for proper professional services. But I am but one person with 30 years of experience and most people my age are way out of this business when they get my age. It does not pay enough for most people, and then there are the issues of self satisfaction with one's work that many people look at and see as an endless road of little satisfaction with restoring vintage gear. Either you love what you do or you don't do it. I happen to love restoring this old gear to it's former glory so that a time and era in my life will live on, and this industry that was so American in its beginnings, will live on after my passing.


I could look at SWAMPWADER's A200 but I just don't want to have the entire inrush of people from your large forum come at me all at once. It would be impossible for me to answer all the e-mails; let alone the do the work. And I would become another heated post on your forum of poor service like I have seen others do in the past. I am not famous, and I don't need to be at my age. I have enough work to keep me busy for a couple months even without lifting a finger to sell or advertize myself. And try as I might, there will be even more work as the next few months go by. I even have old clients calling me asking me to please look at their gear from when I had local services available in a brick and mortar shop. I am blessed I guess you could say to be so much better off then any brick and mortar shop out there. But I been doing this for 30 years, or when Aaron was 5 as I like to look at it LOL...
With that much time at anything, word is bound to get around if your any good at all at what you do.

You can post any of what I said above on your forum at your discretion to help explain to the many why I am "The Stig" and will remain that way until I figure out some way to professionally service all their needs without disappointing any of them.

End of e-mail

Bret
PPI-ART COLLECTOR


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## $LICK CALIFA$ (Feb 9, 2012)

PPI-ART COLLECTOR said:


> Here's a message from The Stig regarding the problem of finding a good tech to fix old school amps:
> 
> I wish I had a easy answer for SWAMPWADER, but I currently have 22 car amps and 6 EQ's waiting. Being a one man operation I tend to get backed up easily with amp restorations. I know that there is a huge market for my services but I am just one person. And if I let everyone send me there gear I would have to buy or rent storage for all the vintage amps out there that folks want brought back to "Like New or Better" operation.
> The fact is that none of this gear was meant to last for ever, no matter how well designed it might have been. And any restoration takes a lot longer then a standard repair on newer gear do. < hence why so many shops decline offers to work on vintage gear, they know it will be a lengthy repair process in most cases. lots of parts and time without exception>.
> ...


this man has obviously been in the biz for a long time and knows the "game"


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## Darth SQ (Sep 17, 2010)

The Stig has sent me another e-mail that details how to do some of your own amplifier diagnosing including a pdf file that includes a diagram.

Here it is:

This post applies to class AB amps only. Class D does not apply to any of this as they are totally different approach to amplification design.

I am attaching a pdf file of where to measure the bias idle voltage on a given set of outputs (the first ones pictured in this case) for you to post in response to post #127 AMPMAN's inquiry about how to set Bias voltage. He will at least need to know where to measure at. And without any Voltage drop across those resistors then they are typically class B amplifiers by technical definition. 

On a finer note: The picture I sent shows only the bias for those two outputs as a single output pair being measured. In the case where there are large arrays of outputs like pictured in the attachment the readings should be checked across each pair of resistors for each pair of outputs. 
The document may look familiar to many veteran tech's as it's devices are common to another brand name of amp on the market. It was part of their tech documents for final test and alignment on new and repaired car amps. 
So any trolls out there be warned your pissing and arguing with a manufacturers testing methods. Plus if you disagree please go back to school and get your degree, it will all make more sense then.

Also when I final test an amp, I actually read each individual emitter resistor's V drop to see if there are any poorly matched outputs of a pair in the group. Big variations in V drop across each individual resistor will be your tell all as to which transistors are likely to not current share evenly. In a PERFECT world each V drop will all read the same across each individual resistor for each individual output with + or - 5% tolerance allowing for the emitter resistor's tolerances. 
I have never seen a perfect world yet, so I use the info to try and replace outputs with the same characteristics so they all current share as evenly as possible when driven to full power. 
Your other option is to gain match sets of outputs for the large arrays with a curve tracer; a fairly expensive piece of test gear that I find invaluable to own if you want to repair amps and analogue pass elements of power supplies and what not, and install entire output arrays with all new devices that have matched characteristics. 

Emitter resistors burn up in value when an amp's output fails so be ready to replace them as needed or the amps output will be compromised since all the amps power flows through those emitter resistors to the speaker load. Any increase in the resistors value will impede the amps output voltage and current capabilities to the speaker load.

Oh and just because you buy transistors with the same date codes. Date codes do not even remotely mean they have matching characteristics in a amps output stage. Larger high quality amp companies order matched gain devices when they buy huge lots of devices for production runs, and even then they individually test each device prior to using them straight from the manufacturer. One of my best friends worked for a large brand name amp company and they tested all semiconductors prior to installation to prevent failures of the production lines product output. So what chance do you have getting matched devices buying bulk devices from a online vendor??? ZIP, Zero, Nada..ain't no way its gonna happen...

Tech's with any time inside amps will recognize what I have posted here as the truth. I just hope you all find it informative and helpful in your audio....."The Stig"

End of e-mail

Bret
PPI-ART COLLECTOR


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## swampwader (Apr 2, 2011)

Just a follow up - 
$LICK CALIFA$ 
_"this man has obviously been in the biz for a long time and knows the "game"_ 
Agreed 100%
PPI-ART COLLECTOR
_( Re: "Here's a message from The Stig regarding the problem of finding a good tech to fix old school amps")_
This message (from The Stig) should be required reading for anyone that is considering *restoration* of anything - be it old amplifiers, vintage espresso machines, or old air cooled Volkswagens. There are just so many worthwhile and valid points that he makes that it would be impossible to quote them all - he "gets it." He understands the concept of restoration. He is a perfectionist. He may even be a bit obsessive -compulsive (in a good way!) Bottom line - this is the type of person that I want restoring my old amp, changing the timing belt on my car, or doing an appendectomy on my kid. NOT a clock puncher or someone just running out the clock until 5 pm every day. I want someone that loves what they do and is passionate about their work. This is (ultimately) always reflected in their work. Stig must feel a tremendous sense of accomplishment every time he finishes bringing one of these old amps back from the dead to "better than new." 
To "The Stig" -  I tip my hat to you sir. You embody all of the qualities of "true" restoration.

On another note - I was contacted by a fellow DIY'er who offered to restore my old amp. I could tell by his message that he also had a passion for his work and would treat my amp as if it were his own. I'm confident that my old amp is in good hands.

Thanks to all that posted and offered their help. It was greatly appreciated.

swampwader


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