Worth it to restore Sansui AU and TU 717

1. It's an old unit
2. It still works without any immediate issues.
3. It is capable of sounding good enough to be your final amp
4. Let someone who knows what they are doing replace the parts that will ensure it keeps sounding good long after you've forgotten the cost of servicing it.
:D
 
I was recently with a guy who has the same tuner. That is definitely a wonderful tuner, sondwise, but also looks wise. With its black front it's very non-seventies.

It is in the top 20 of fmtunerinfo with good reason.
 
RAJOD said:
I have seen very little on why people restore the amplifier.

I can see if it does not work or there is some distortion in the sound.

But do people restore a perfectly good working unit?

The Sansui I purchased has never been out of its racks. Use very little over the years. So any corrosion would be from air to part contact.

The glue seems to move around from heat. If the amplifier was never used in 30 years the glue should not move anywhere. People have to scrap it off, it does not liquify on its own. The amplifier would need to provide the heat to melt it.

Now capacitors can dry out just by sitting around. Buttons, switches can oxidize to the point they do not function.

Wondering if anyone has done a full restoration on a working unit (no issues) then afterwords thought "hmm sounds the same" waste of time.
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Re: the glue, it doesn't "move around with heat". The glue stays in place as per when it was originally applied to hold the capacitors in place. The trouble is, it is always slopped over adjacent components, and where it touches the metal legs of components, it corrodes them. It's not a case of 'if' it happens, but a matter of how bad the damage is.

I have fully restored a number of my own personal amps which were working just fine (including my 1987 AU-X701) and each amp sounded better afterwards (some more noticeable than others). I've never found it to be waste of time, nor have the other people whose amps I've worked on.

IMHO, anyone listening to older equipment which is 100% original is listening to sonically compromised gear. Components (capacitors in particular) have a finite lifespan and their performance deteriorates as they age.
 
My experience with both the 517 and 717, having repaired and/or restored quite a few of these, is that the glue will eventually cause problems, and then a failure of the amp. In all of the unit I have worked on, only one had glue that had not "gone off", although there were signs that this had started to occur.

I have seen offset problems caused by glue damage to the smoothing caps on the main amplifier boards and channel failure due to power supply component corrosion on the power supply board. I have also seen component leads 99% eaten thought by the glue that would fail in a short time if not replaced. Your comment regarding the glue spreading over time is not right, the way the glue is now (the area it covers and the components it is in contact with) is the same as it was when new.

Removal of the glue, replacing affected components, replacing other component that have known issues like the fuse resistors and VD1212 diodes are not done to improve the sound, and the decision to do a full recap at the same time again is not done to specifically improve the sound, but to restore the amp to its original working condition and improve future reliability.

If the amp, before the work was carried out, had low or no bias current due to failed fuse resistors, power supply problems or out of spec signal path caps then an improvement in sound quality would most likely be noticed.

Have a search on the forum, there are a few threads on Au717 restorations that show the effects of the glue.

These is my thoughts based on my experience, others may have a different view. Ultimately it is up to you to decide. At least take off the cover, get some good lighting or a torch and have a look at the power supply board and around the large caps on the main amp module boards and see what condition the glue is in.

Link to a 717 with glue in "good" condition

http://www.audiokarma.org/forums/showthread.php?t=544077

and here is one that needed a little TLC

http://www.audiokarma.org/forums/showthread.php?t=469502

Cheers

John
 
Yea the first 717 repair link he went all out and replaced the Huge capacitors. I hear they rarely ever go bad.

Wonder what that type of overhaul would cost? Lot of labor in it.

I have repaired many PC parts over the years but never an amplifier. I think I could do it but would be a learning experience for sure.

Wonder if they use Artic silver heatsink coumpound used on many PC heat sinks for the output transistors.

The reason I would want to do it myself is over the years with cars, boats, computers etc. I've paid people to do work for me and often ends up being subpar work. Meaning the same work done by me is better. People today are lazy, no good ole USA pride in the work.

If I could find that type of guy I would use him for a restoration. Just had too many turds in the past.
 
8golftango said:
Good God!! How did u pull that off??? 200 dollars!?!????:banana:
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I think the key to pulling that off was I did not care about it. I'd seen that amp in the record store for a long time. Never really looked at it as I was buying old turntables and just ordered a new Outlaw Retro Receiver. If I was going to get an old amp it would have been Pioneer I think. Had no interest in Sansui.

I think the price started out like 1,100, then each week it kept going lower.

The owner wanted to get it out of there as it was just taking up space.

So I offered 200.00 just for kicks. He said if you have cash then deal, I had cash so i got it. Was not really prepared to get it. Had to move it to my car by myself and it probably weighs over 100 lbs. Saw a few college guys in parking lot and they helped me load it. I don't think I could have done it by myself.
 
RAJOD said:
Wonder if they use Artic silver heatsink compound used on many PC heat sinks for the output transistors.
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NO!

:nono:

Heat sink compound made for CPU's almost always have a metallic component in them, in the case of Artic Silver, it has... Silver. If a transistor has a metal tab, that tab is almost always connected to the collector. Using a metallic compound could cause a short to the heatsink/ground. Very, very not good.

Use a silicone based, non metallic compound.
 
Livin4 said:
NO!

:nono:

Heat sink compound made for CPU's almost always have a metallic component in them, in the case of Artic Silver, it has... Silver. If a transistor has a metal tab, that tab is almost always connected to the collector. Using a metallic compound could cause a short to the heatsink/ground. Very, very not good.

Use a silicone based, non metallic compound.
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LOL, Artic Silver is the name of the company not all the products are the same.

http://www.arcticsilver.com/cmq2.html

And to remove the old gunk they have a super solution, it cleans up the mess in seconds like magic.

http://www.arcticsilver.com/arcticlean.htm
 
Hyperion said:
Don't waste your money - if it is the white stuff that needs cleaning I use WD40 - works a treat ;)
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Yep, what he said. There's no point forking out for fancy thermal pastes for amp restoration. Stick with decent quality standard paste and you'll be fine.

The actual amount of thermal paste used is so minor that the difference between pastes is minimal at best in any case. How properly (and sparingly!) the paste is applied is more important than the brand or model of paste in this instance.
 
pete_mac said:
Yep, what he said. There's no point forking out for fancy thermal pastes for amp restoration. Stick with decent quality standard paste and you'll be fine.

The actual amount of thermal paste used is so minor that the difference between pastes is minimal at best in any case. How properly (and sparingly!) the paste is applied is more important than the brand or model of paste in this instance.
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I bought a small tube, seems like years ago, and have since done the following...

AU-717, 1000X, AU-9900, AU-317, AU-517, 2 x AU-719, AU-D101, AU-919, AU-D11 II, AU-X701, and a BA-5000 and I STILL have about 1/3 of the tube left.
 
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RAJOD said:
LOL, Artic Silver is the name of the company not all the products are the same.
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Ah! Good to know, although the tube I have does contain silver.

RAJOD said:
And to remove the old gunk they have a super solution, it cleans up the mess in seconds like magic.
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I just use IPA (isopropyl alcohol)

Hyperion said:
I bought a small tube, seems like years ago, and have since done the following...

AU-717, 1000X, AU-9900, AU-317, AU-517, 2 x AU-719, AU-D101, AU-919, AU-D11 II, AU-X701, and a BA-5000 and I STILL have about 1/3 of the tube left.
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Yeah, me too. I picked up 3 tubes for a really good price some years ago and haven't finished the first one yet.
 
pete_mac said:
Yep, what he said. There's no point forking out for fancy thermal pastes for amp restoration. Stick with decent quality standard paste and you'll be fine.

The actual amount of thermal paste used is so minor that the difference between pastes is minimal at best in any case. How properly (and sparingly!) the paste is applied is more important than the brand or model of paste in this instance.
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I already own it. I've been building PCs for 20 years. The remover is good better than WD for sure.

As far as using it, I already use it for computers, it might be overkill for a amp but I already have lots of it.
 
Livin4 said:
Ah!
I just use IPA (isopropyl alcohol)

d haven't finished the first one yet.
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I use to use ISO for removing heatsink grease. Thought that this might be a gimmick. OMG its not, it takes it off fast no mess. Its 100x better than ISO. I was amazed at how fast it was and mess free.
 
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