Hey guys, I found alot about tube refurbishing and repair but not SS amps.
I was wondering if a good approach would be to look for some good older, vintage SS amps for repair for a low cost option to higher power?
If so, what amp manufacturers should I really be looking at? I know McIntosh and Marantz are popular but I would take anything at this point as I am trying to just get into audio design and repair.
I would prefer SS amps as well because my system is for music and movies so it would better to have SS than tubes for me.
I know the MC2105 seems to be very popular old McIntosh but I really am at a loss.
I was going to build an F5 until the heat went out in the car and now I am looking for another job so I think it would be better to look at doing some restoration work instead of starting from scratch.
I was wondering if a good approach would be to look for some good older, vintage SS amps for repair for a low cost option to higher power?
If so, what amp manufacturers should I really be looking at? I know McIntosh and Marantz are popular but I would take anything at this point as I am trying to just get into audio design and repair.
I would prefer SS amps as well because my system is for music and movies so it would better to have SS than tubes for me.
I know the MC2105 seems to be very popular old McIntosh but I really am at a loss.
I was going to build an F5 until the heat went out in the car and now I am looking for another job so I think it would be better to look at doing some restoration work instead of starting from scratch.
I like Peavey's and Dynaco's. The schematics are available on line. The parts are US code mostly and datasheets can be downloaded. Even the private label peavey parts, there is an interchange to OEM number list. The Peavey CS800s and CS800x and the dynaco ST400 and ST410 have good sound specs, and the CS800s sounds great when the power supply is not tripping the breaker (14 years old, needs e-cap probably).
Salas tutorial to refurbishing old amp is here http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
Look around old musician resale shops as well as the usual suspects craigslist ebay. I got a PV-1.3k blown up (not transformer) for $55 and a CS800s (input resistors toasted) for about $100. Dynaco ST400's are going for about $300 working, unrestored.
Older CS800 amps don't have as good sound and lack the speaker protection circuits of the x & s suffix. Nor do I expect a lot soundwise out of the PV=1.3k. The PV1.3k and Dynaco ST400 lack effective speaker protection, I'm installing it now in the PV-1.3k. The dynaco ST120 has sound issues and blows OT's a lot unless the heat is managed better, but is extremely easy to fix. The ST120 can't blow up a speaker until it shorts a 100 v cap in series with the speaker. Great feature, especially if your speakers cost more than the amp. I've upgraded my ST120 to sound like the CS800s with a djoffe bias board and fans, see this thread:http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
Salas tutorial to refurbishing old amp is here http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
Look around old musician resale shops as well as the usual suspects craigslist ebay. I got a PV-1.3k blown up (not transformer) for $55 and a CS800s (input resistors toasted) for about $100. Dynaco ST400's are going for about $300 working, unrestored.
Older CS800 amps don't have as good sound and lack the speaker protection circuits of the x & s suffix. Nor do I expect a lot soundwise out of the PV=1.3k. The PV1.3k and Dynaco ST400 lack effective speaker protection, I'm installing it now in the PV-1.3k. The dynaco ST120 has sound issues and blows OT's a lot unless the heat is managed better, but is extremely easy to fix. The ST120 can't blow up a speaker until it shorts a 100 v cap in series with the speaker. Great feature, especially if your speakers cost more than the amp. I've upgraded my ST120 to sound like the CS800s with a djoffe bias board and fans, see this thread:http://www.diyaudio.com/forums/solid-state/136261-vintage-amplifier-repair-upgrade-manual.html
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Lots of well-built amps out there worthy of re-capping and bringing back to life, like this Kenwood Supreme 600 (if you can find one):
Another option is to just re-use the chassis, power transformer, and possibly the heat sinks, with completely new DIY boards inside.
An externally hosted image should be here but it was not working when we last tested it.
Another option is to just re-use the chassis, power transformer, and possibly the heat sinks, with completely new DIY boards inside.
From experience, amps with complex DC servos can be tricky for the beginner or intermediate - e.g. my Adcom GFA 585 and it's relations - capacitor electrolyte all over the sensitive areas of a circuit board can really upset things...
I recently revived a Dynaco ST400 - not too hard to bring back to life, plus there's a lot of interesting resources on the internet due to interest in these products. That helped me choose appropriate output device replacements and learn about common problems and their solutions.
It's always worth investing in the service manual, especially if one intends to keep the amp, so that is perhaps the basis of another tip: search and see if reprints or copies of these are available before you buy.
Build an 8 Ohm dummy load with some big resistors; get a Variac and know when and when not to use it.
Good luck - there's plenty of fun SS gear out there to play with.
Ed
I recently revived a Dynaco ST400 - not too hard to bring back to life, plus there's a lot of interesting resources on the internet due to interest in these products. That helped me choose appropriate output device replacements and learn about common problems and their solutions.
It's always worth investing in the service manual, especially if one intends to keep the amp, so that is perhaps the basis of another tip: search and see if reprints or copies of these are available before you buy.
Build an 8 Ohm dummy load with some big resistors; get a Variac and know when and when not to use it.
Good luck - there's plenty of fun SS gear out there to play with.
Ed
As Indianajo suggested, Dynaco Stereo 120's are plentiful, and have lots of room to work on them. Lots of folks like them dead stock, some add some more microfarads here and there, maybe do the TIP mod...(shameless commerce warning) I sell some kits that change out original amp modules and power supplies (do as little or as much as you like) at Update My Dynaco.
If you're pretty skilled a Dynaco Stereo 400 could be a great value. I just bought one that I restored and am keeping for my own, but the fellow I bought it from had 2 more for sale.
If you're pretty skilled a Dynaco Stereo 400 could be a great value. I just bought one that I restored and am keeping for my own, but the fellow I bought it from had 2 more for sale.
djoffe, that was goign to be my next question to see if there was a way to improve them...I am glad to see there are kits!
How does going the route of repairing vintage amps compare to the approach of building an F5? It seems to be cheaper but is there any other benefit to building from scratch that I need to consider?
How does going the route of repairing vintage amps compare to the approach of building an F5? It seems to be cheaper but is there any other benefit to building from scratch that I need to consider?
It really depends how much you want to personalize what you do, and how much time you have.
Refurbing an old amp avoids most of the mechanical and construction issues. That's good or bad, depending upon what you're equipped to do, and what you like to do.
The F5 looks like a neat design...Nelson Pass of course, does nice work! A quick look around the net shows people selling parts and boards. I'm sure other people reading this thread could provide a good collection of links that would allow you to collect everything you need to build...case, switches, power supplies, heatsinks..It can definitely be a lot of fun, and a lot of work!
An alternative (warning: shameless commerce plug)...is my product, the Akitika GT-101. It's a complete amplifier kit...everything collected in one kit...you just add solder and labor.
Akitika GT-101
Any of these options can be very rewarding, and a lot of fun!
Refurbing an old amp avoids most of the mechanical and construction issues. That's good or bad, depending upon what you're equipped to do, and what you like to do.
The F5 looks like a neat design...Nelson Pass of course, does nice work! A quick look around the net shows people selling parts and boards. I'm sure other people reading this thread could provide a good collection of links that would allow you to collect everything you need to build...case, switches, power supplies, heatsinks..It can definitely be a lot of fun, and a lot of work!
An alternative (warning: shameless commerce plug)...is my product, the Akitika GT-101. It's a complete amplifier kit...everything collected in one kit...you just add solder and labor.
Akitika GT-101
Any of these options can be very rewarding, and a lot of fun!
Depends on you skills. I enjoy soldering, but have no skill or tools for building a great-looking chassis, so resto-mod was the route I chose for my latest project, a Dynaco SCA-80Q.
djoffe, had I known about your Dynaco boards, I might have tried them, but found Michael Renardson's MJR7 board, which nicely fit the single-rail requirement on the Dynaco's existing transformer, and is an exceptionally well-document design.
I love the way vintage gear looks, but this particular Dynaco had old dried out caps, and a 1960's design with super hot resistors and very high (by today's standards) distortion. So, it still looks great externally, but has much better specs, and should last a very long time.
djoffe, had I known about your Dynaco boards, I might have tried them, but found Michael Renardson's MJR7 board, which nicely fit the single-rail requirement on the Dynaco's existing transformer, and is an exceptionally well-document design.
I love the way vintage gear looks, but this particular Dynaco had old dried out caps, and a 1960's design with super hot resistors and very high (by today's standards) distortion. So, it still looks great externally, but has much better specs, and should last a very long time.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I have my own workshop where I repair vintage equipment wich is sent to me from the most of Norway, and even some Swedish and Danish "customers" too.
"Customers" as this is deone entirely on my spare time, and the ones sending such to me MUST be very patient. This due to things I rather not tell in full here.
TANDBERGEREN is an acronym for: He who saves TANDBERG equipment.
"Customers" as this is deone entirely on my spare time, and the ones sending such to me MUST be very patient. This due to things I rather not tell in full here.
TANDBERGEREN is an acronym for: He who saves TANDBERG equipment.
I can revcomend You one to contact if the urge for TANDBERG gets too strong.
In California he is.
Sounds like you are a "secret agent"
Well I look forward to learning more bout amplifier repair for fun...it looks like it could be more worth my time to buy old and repair the broken ones rather than start from scratch....
I think it could be alot of fun to start from scratch...but I think it is better to walk first....
I also want to experiment with McIntosh and other manufacturer's offering...to see if I can really tell a difference in sounds from an amp....I have a hard time believing it is that audible. However, I do believe the way an amp distorts has a certain sonic signature...
Secret agent, well wouldn't call it that in any way, since I operate in the open field all the time.
Yes, repairing theese oldies is quite fun.
I have spent the most of the last ten years searching for components and other spare parts all around the world. Most of the bits and pieces I have here now I found in the states. And for far better prices including shipping than here in Europe.
But still all too much. Seemed like some thought they had some gold nuggets when holding a plasticbag with a TANDBERG sticker on. Almost no care of what really was inside.
The second "problem" is to find schematics.
Fortunately there has arrived a lot of free databases all around, but still there is scarce for some of the finer equipment. And as a strike of luck, the other day I was notified by a friend, who had bought a full garage of TANDBERG-stuff from a former employee there.
Including about all the service documentation ever available.
For other brands I know the B&O and Philips clubs have been quite good at collecting documentation. Well, there has been some time since I was in need of anything from any of them, apart from Philips, who told me that they dump all documentation for products elder than 5 years. I really hope the Philips-clubs around has taken their measures for that.
Also the High-End brands are often quite hard to get documentation from.
Even Per Abrahamsen can't get me any schematics for his own amplifiers when he ran the Audiocompagniet. For some other vintage High End brands here in Norway, I hava managed to get in touch with one of the founders of ADYTON. They had a brand earlier callet SONOTRON where most of the techniques ADYTON now uses was invented.
When asking if one learn more by repairing existing equipment than by building an amp oneself, I must be honest to say that it depends strongly wether one have qualified help or not doing either of the methods. It is easier to learn the principles when building an easy project first, then a harder one, and then the full thing, rather when trying to understand often quite complex cirquitry used in some of also the vintage amps.
The only DIY-projects I don't recommend as projects to learn something from is the "all in one" chip-amps. They are good for getting a new amp one has built one self, and little more. Better building an 5Watt discrete amp actually.
And Yes, there is some sonic differences between the different brands, series within a brand, and also between different generations within a brand.
Modern amps are harder to tell the difference between one or the other.
The manufacturers has gotten very close to an ideal some manufacturers proclaimed they had reached already in the seventies: The amplifying wire.
I guess there will be too little difference within say ten years.
Sad actually. Will kill all discussions about what amp is the best.
And they are close, very close.
Yes, repairing theese oldies is quite fun.
I have spent the most of the last ten years searching for components and other spare parts all around the world. Most of the bits and pieces I have here now I found in the states. And for far better prices including shipping than here in Europe.
But still all too much. Seemed like some thought they had some gold nuggets when holding a plasticbag with a TANDBERG sticker on. Almost no care of what really was inside.
The second "problem" is to find schematics.
Fortunately there has arrived a lot of free databases all around, but still there is scarce for some of the finer equipment. And as a strike of luck, the other day I was notified by a friend, who had bought a full garage of TANDBERG-stuff from a former employee there.
Including about all the service documentation ever available.
For other brands I know the B&O and Philips clubs have been quite good at collecting documentation. Well, there has been some time since I was in need of anything from any of them, apart from Philips, who told me that they dump all documentation for products elder than 5 years. I really hope the Philips-clubs around has taken their measures for that.
Also the High-End brands are often quite hard to get documentation from.
Even Per Abrahamsen can't get me any schematics for his own amplifiers when he ran the Audiocompagniet. For some other vintage High End brands here in Norway, I hava managed to get in touch with one of the founders of ADYTON. They had a brand earlier callet SONOTRON where most of the techniques ADYTON now uses was invented.
When asking if one learn more by repairing existing equipment than by building an amp oneself, I must be honest to say that it depends strongly wether one have qualified help or not doing either of the methods. It is easier to learn the principles when building an easy project first, then a harder one, and then the full thing, rather when trying to understand often quite complex cirquitry used in some of also the vintage amps.
The only DIY-projects I don't recommend as projects to learn something from is the "all in one" chip-amps. They are good for getting a new amp one has built one self, and little more. Better building an 5Watt discrete amp actually.
And Yes, there is some sonic differences between the different brands, series within a brand, and also between different generations within a brand.
Modern amps are harder to tell the difference between one or the other.
The manufacturers has gotten very close to an ideal some manufacturers proclaimed they had reached already in the seventies: The amplifying wire.
I guess there will be too little difference within say ten years.
Sad actually. Will kill all discussions about what amp is the best.
And they are close, very close.
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