Sansui AU-717

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.

I generally live by the “if it ain’t broke, don’t fix it” philosophy but suspect that may not apply here. 

@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!

and much better bridge components……the world does get better

@atmasphere 

Hi Ralph.
 

I fear you have given me credit/quoted me with something I didn’t say :)

I was arguing for the recap of the unit. Firm believer in the benefits of both replacing old/tired caps with fresh ones, but also taking advantage of the opportunity to put higher quality parts in the piece.

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?