Sansui AU-717 Integrated Amp-question

[Chocaholic]

Bought it new around 1975 while still in high school. That was 40 years ago. It's never needed any kind of service and its in use as I write this. Sound quality is just as amazing as ever.

But...if I go a few weeks without using it, it powers up but I get no sound out of the left channel. To resolve, I crank the volume way up very quickly and the left channel snaps to life and works/sounds great. If used frequently, no problem.

Just did it again tonight after a few weeks off. Hate to take it to a hack as the unit has sentimental value and I don't want it damaged. Hard to ship as it probably weighs 50 lbs.

Any thoughts or ideas? I'm not afraid to pull the cover off and spray some contact cleaner around but thought I'd defer to the brain trust first.

Thanks.

[Gogar]

Check the connections on the speaker cables. Even if they look ok, re-do them.

[imcarthur]

The volume pot (potentiometer) needs some love or replacement.

Ian

[Por_sha911]

Sometimes the pot needs cleaning. CRC Electronic cleaner. Just make sure the unit is powered down.

[djantlive]

Where do you spray the cleaner? Directly on the volume knob edges or from inside?

[Ayles]

Man that thing is awesome! At that age I'd also look inside for swollen or leaking capacitors.

[SpyderMike]

You might check at Audiokarma.org Home Audio Stereo Discussion Forums .

[LeeH]

Do you get the same results over headphones?

I'd clean the volume, balance, source selector pots. Unplug. Remove the cover, spray contact cleaner into the pots. Work them back and forth. Let dry completely. Look for swollen capacitors, heat damage to the boards while you're in there.

Shooting contact cleaner behind the knobs isn't going to get it where it needs to go. As you can see by the pic, the selector pot is nowhere near the knob.

You're right. You don't want to take it to a hack, but I'm thinking if you ask around, you can find a pro who can go through it. Most stereo hobbiests have a guy on their contact list who can track down and fix this sort of thing for not a lot of money. I have one here in Phoenix.

[robertocravallo]

Originally Posted by Chocaholic

Bought it new around 1975 while still in high school. That was 40 years ago. It's never needed any kind of service and its in use as I write this. Sound quality is just as amazing as ever.

But...if I go a few weeks without using it, it powers up but I get no sound out of the left channel. To resolve, I crank the volume way up very quickly and the left channel snaps to life and works/sounds great. If used frequently, no problem.

Just did it again tonight after a few weeks off. Hate to take it to a hack as the unit has sentimental value and I don't want it damaged. Hard to ship as it probably weighs 50 lbs.

Any thoughts or ideas? I'm not afraid to pull the cover off and spray some contact cleaner around but thought I'd defer to the brain trust first.

Thanks.

Cool, my dad and I had that exact amp. My dad, he is 93, still has his and also the same tuner you have! Still works great! Whatever happened to SANSUI?

[Chocaholic]

Great suggestions guys. Much appreciated. Will redo speaker connections...easy enough. Supposed to be crappy weather today so the pots may get a shpritz too.

Not sure what happened to Sansui. Saved paper route money for two years to buy that amp. Was nothing in the world I wanted more as a teenager. Tuner came years later (used) and have used it maybe twice. With a 16 year old of my own, well, amazing how times have changed!

[imcarthur]

Originally Posted by robertocravallo

Whatever happened to SANSUI?

In the early to mid 80s, the Japanese manufacturers started shifting focus & production away from high quality products built in Japan to cheap but very profitable products built in other Asian countries. The advent of home theater in the early 90s completed the transition toward dreck. The better-sounding high quality role was filled by smaller boutique manufacturers from Western countries - often manufactured to spec in the same plants that were churning out garbage for the masses.

Ian

[javadog]

Ian,

Given that prices for old 2 channel gear are pretty low now, apart from the high end exotic stuff, any recommendations for amps in the 250W-and-up/channel range? I'm looking for something I could buy for a couple hundred dollars that would be of reasonably high quality. Integrated, or separate, would be fine.

Excuse the hijack,
JR

[Chocaholic]

250w? Per ch? RMS? Into 8 ohms??? Are you trying to crack a concrete foundation?

The AU-717 is 85 RMS per side and could easily inflict deafness if speaker windings didn't melt first.

In any case...just inserted this in the rack while I dig into the Sansui pot-clean job:

[javadog]

It may sound like a lot, but 100W/channel isn't enough for my speakers and room.

Back to your problem, there's usually a guy in most decent-sized towns that works on older electronics, repairs speakers, etc. I'd probably suggest taking your amp to one of those guys. I have one in my town, which is not the hi-fi center of the universe.

JR

[KFC911]

Originally Posted by javadog

Ian,

Given that prices for old 2 channel gear are pretty low now, apart from the high end exotic stuff, any recommendations for amps in the 250W-and-up/channel range? I'm looking for something I could buy for a couple hundred dollars that would be of reasonably high quality. Integrated, or separate, would be fine.

Excuse the hijack,
JR

Originally Posted by Chocaholic

250w? Per ch? RMS? Into 8 ohms??? Are you trying to crack a concrete foundation?

The AU-717 is 85 RMS per side and could easily inflict deafness if speaker windings didn't melt first.

In any case...just inserted this in the rack while I dig into the Sansui pot-clean job:

My vintage '70s stuff wasn't black....think silver JVC

I know there are some serious amp guys on here, and I need some advice for bringing my assortment of gear back for minimal $. I need power too...lots of it, and it's not about volume....just inefficient Polk towers that have a lot of drivers

I've got two dead Carvers and another one fading fast....hmmm, another thread maybe

[imcarthur]

Unfortunately, it is hard to recommend used products because they vary so wildly. My first question is why do you need 250W? Of course there are watts & there are watts. 250W of 80s & post-80s Asian gear = 50W of well-built American or Euro gear (as long as the speaker efficiency > 89dB). The best illustration of this occurred when Naim (of Salisbury England) launched their Nait integrated amp around 1984. A tiny – but hefty – integrated amplifier that would drive almost any speaker & it was only 14Wpc. The quality of the components – particularity the transformer & power supply – have a far more positive effect on sound quality than high wattage crap with a minuscule block transformer. I always look for a toroidal transformer in the power supply of solid-state amps because they inherently have better current delivery than standard block transformer designs & current is what speaker voice coils need to dance. Of course, it is also a specification that is rarely quoted so only your ears can tell, although the heft of an amplifier is often a telltale clue.

The major downside to a vintage purchase is the aging of the internal components. Volume pots get scratchy or have dead zones – like the above. Capacitors leak. Wiring is scorched & oxidized. Output devices fail. And customized parts are often NLA, so it is buyer beware.

Ian

Disclaimer: I now represent Naim so I am biased.

[javadog]

Well, I recently sold off some of my gear. I had a pair of Krell FPB-250M monoblocks which worked well with my speakers and room (fairly large, 700-800 Sq. Ft.) After selling them, I was fiddling with a recent Yamaha 5 channel receiver belonging to my kid and hooked it up to a set of speakers to test some functionality. The question at hand had nothing to do with playing a pair of stereo speakers but, since it was hooked up, I ran a few songs through it just for curiosity's sake. I don't recall the specifics of the unit, but it was in the 100W range when driving 2 channels.

It was not impressive. Pathetic, really. Hard to describe but it was awful.

I have an older Denon amp in my office that is rated at 160 Watts/channel and it does fine, but that room is maybe 20% the size of the other one.

Nothing scientific here, and not looking for the ultimate in sound quality, just want something decent. There are so many choices out there, I thought I'd get some idea of which brands are worth looking at. I realize that any older piece of gear may have issues, but a for a couple hundred bucks or so, let's say that if it works when I audition it, I'll take a chance on it lasting for a little while.

You've been in audio forever, so I thought you might have some ideas.

JR

[imcarthur]

i am a purist.

What are the dimensions of the room? What speakers? In a large room, you need larghish speakers to excite enough air to fill the space realistically. Or just sit closer to smaller ones & give up low bass unless you use a 2.1 system with a powered sub. What speaker did you use with the Krells? Krell inherently always had a forward punchy sound iirc.

Ian

[Chocaholic]

Acoustic music through a 6 wpc/ch single ended triode can fill a large room with sublime reality a behemoth Krell couldn't touch (through efficient horns or similar).

Why not consider a more efficient speaker (88db+) with a higher quality lower powered amp? Just a thought.

[javadog]

The room is roughly 24 by 30 feet, although the end where the stereo gear is placed is a little narrower, as there are a couple encroachments from the roof design, on either side. Speakers were usually Energy Veritas, from the great white north. Not the ultimate, but a decent performer for the price, in their day. The listening couch is usually slightly closer to the sound system than the room center, which is where it needs to be given the spacing and position of the speakers. No sub. Lots of other crap in the room, so acoustics weren't horrible. I bought some software to analyze the room acoustics, but haven't gotten around to doing anything yet.

Once upon a time I used a tube amp, not going down that path again...

JR