The unit is very easy to dismantle and work on .
Discharging the Caps is where you need to be careful.
Schematics are available on line-Tech needs an Oscilloscope -Some soldering skill and a Variac wouldn't hurt.
cheers
Sansui AU-717
Bought my AU-717 integrated amp new in 1977. Have used it intermittently over the years and it works and sounds great, 45 years later. The cover has never been off and I still have the owners manual. Any reason to have it serviced? Caps, etc? If so, why? And can you recommend a knowledgeable service resource in the Atlanta area?
I generally live by the “if it ain’t broke, don’t fix it” philosophy but suspect that may not apply here.
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@chocaholic Any technician competent enough to service a Japanese receiver can do the work just fine. Just have him put in Nichicon or similar quality capacitors and you'll be fine. Bonus tip: ask him to use SN63 solder if he does not already. SN63 is a 'eutectic' solder which means its almost impossible to get a bad solderjoint with it since it goes from liquid to solid so quickly. |
I would honestly go to DIYAudio or Audiokarma and reach out to the folks there for some thoughts on where to send it.
Understand the reluctance to ship, and you may get lucky and find someone near by. But, better to ship to someone who will do it right? Again, the person you are looking for, could live within driving distance and may be a retired tech who is working out of their basement - someone only be found through community circles. Secret handshake is a must… |
I’m convinced. The challenge now is finding the “right” guy to do the work. I called Audiolab in Atlanta and was told “a few months” before he could look at it. This after several reviews referencing exceedingly long lead times (up to a year in some cases). I prefer to not ship it and am willing to drive a few hours if needed. I suspect it’s not rocket science but this amp has sentimental value beyond its function so I’d like it to be optimally serviced. Any suggestions? |
@perkri It may seem to work but I guarantee its suffering and not performing to spec. When the filter capacitors in the power supply fail one way they can go is to start to run warm. When this happens they are drawing a bit more current. As the current inches up the power transformer runs warmer too. Eventually this can lead to power transformer failure which can be really painful- something that is cool and interesting has suddenly taken on a lot of the properties of a brick. The transformer can be really pricey if you actually fine one for sale! They don't always bulge- the plastic sheath around them will sometimes shrink but they might also just look fine. Don't be fooled- they are way too old to be any good. So if you plan to run this amp get the filter capacitors in the power supply replaced at the very least! Its overdue. Its also not a bad idea to replace electrolytic coupling caps wherever they might occur! |
Such a lovely vintage Sansui deserves a health check by a competent EE, as it is inconceivable that the amplifier will not be running out of bias at the very least. Likewise miraculous were a good number of lyrics and carbon resisters not to have drifted well out of specification, ergo you will not be experiencing that AU-717 as it was designed to perform.
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I recapped a PS Audio power plant some years ago. Yah sure it worked fine and the caps were not bulging. They were however very dry. In fact, you could shake them and they sounded like baby rattles!!! So this nonsense of "it looks good to me" or "don't fix it if it ain't broken" is never something that I assume. 45 years is good luck on your part, but as someone mentioned here. it might not go quietly in the night and that's that. Hostages could be involved. |
The 717 is on my wishlist! I’ve recapped many amps myself. At a minimum, get the power supply caps looked at. Electrolytics have a shelf life of between 30 and 40 years. They dry out. I don’t understand the desire to keep these things “original”. It’s not a vintage Ferrari… As long as the caps are replaced by a tech who knows what they are doing, you’re just going to improve the sound of it. And, it’s operational safely. A big cap goes, and it can have a cascading effect taking out transistors in its path. I also recapped a 2230 last year, and was going to sell it, but was gifted an Ariston RD11S that I’m restoring for fun. So I’m keeping the 2230 as they are a good match as a 2nd system. Get the 717 power supply caps done at a minimum, and if you want to keep it running for another 40 years, get the whole thing done. Do some research online - diyaudio or audiokarma - and find out who the best rebuilders/restorers are and send it out to get done right. Unless you are comfortable buying the parts and doing it yourself. when you get it back, it will sound as it did when new, only better…
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@chocaholic recap for audio electronics is like oil change and spark plugs for car. ur car may not have ever broken down, but but u still give it an oil change and new spark plugs when its time to do so. |
The 717 is one of the best built Sansui integrated of its time dual mono internal design etc. very robust build. that said the whole "if it isn’t broken don’t touch it" thing is so very wrong in a whole lot of ways. you would not get on an airplane that had maintenance plan like that would you? obviously, an integrated amp is not an airplane, but all things degrade over time. so, get it checked. I highly recommend getting it serviced specially if it’s never been in before. one, the bias is going to be way off by now, the caps are getting very old and have drifted out of spec most likely if not already starting to fail. the list goes on. The 717 is highly regarded on the use market as well and commands top dollar if in good shape, and the prices are only going up as more people see how good these Sansui’s were. If it was mine, I’d have it restored and brought up to factory spec you will be surprised how much better it will sound after a refresh. I’ve done all my Sansui vintage stuff now and everyone was better after a refresh. I’ve done an; AU 20000, CA 2000, BA 2000, TU 9900. At minimum get it checked, contacts cleaned and lubed and re-biased. at least you’ll know if there are hidden issues. you never know when that 40-year-old component will fail and take out the amp section or make it too much to repair. Always get older vintage pieces at least checked don't be the guy who thinks if it isn't broken don't fix it bull crap. that's how you ruin a good amp.
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