"Alisdair" bravely wrote to "All" (13 Sep 03 18:38:54)
--- on the heady topic of "Help needed fixing Sansui AU-101 amp"

Being an old amp and assuming it has been sitting unused for a long
while, I would highly suspect the most typical problem being marginal
aluminum can electrolytic capacitors. You have to ESR every electro in
the amp and change all that turn up bad. Only then you can go on to
diagnose other faults. Everyone here will offer the same advice.


Al From: Alisdair

Al hi,

Al I've just got an old Sansui AU-101 amp, and it has a few problems:
Al - there's no output on the right channel until it's been on a few
Al minutes - both channels (but particularly the right) crackle when
Al balance or volume are adjusted. Once the unit has warmed up the
Al problem with the volume goes away.

Al The sound quality is ok though once it's warmed up.

Al I've done some searches and found suggestions for similar situations,
Al like freezing transistors or replacing caps (largest first), any idea
Al what to try first? I've done some electronics in the past so I'm not
Al completely ignorant, never tried to recondition a hi-fi before though.

Al I'd appreciate any suggestions as to what to try, especially related
Al to the AU-101 in particular.

Al Thanks,

Al Alisdair

.... A fail-safe circuit will destroy others.

Smaller caps near a heat source, yes. Others, probably not.

Dirty controls & switches, number one.
Solder connections, number two.

Other, more obscure sources of bad connections, number three. I worked on an
old Sansui integrated (sorry-don't remember the model number) on which the
B+ voltage for the outputs was lost intermittently due to bad physical
connections to the TO-3 devices.

A tech could probably fix it in pretty short order. A do-it-yourself-er,
well, maybe, maybe not.

Mark Z.


"Asimov" wrote in message
...
"Alisdair" bravely wrote to "All" (13 Sep 03 18:38:54)
--- on the heady topic of "Help needed fixing Sansui AU-101 amp"

Being an old amp and assuming it has been sitting unused for a long
while, I would highly suspect the most typical problem being marginal
aluminum can electrolytic capacitors. You have to ESR every electro in
the amp and change all that turn up bad. Only then you can go on to
diagnose other faults. Everyone here will offer the same advice.


Al From: Alisdair

Al hi,

Al I've just got an old Sansui AU-101 amp, and it has a few problems:
Al - there's no output on the right channel until it's been on a few
Al minutes - both channels (but particularly the right) crackle when
Al balance or volume are adjusted. Once the unit has warmed up the
Al problem with the volume goes away.

Al The sound quality is ok though once it's warmed up.

Al I've done some searches and found suggestions for similar situations,
Al like freezing transistors or replacing caps (largest first), any idea
Al what to try first? I've done some electronics in the past so I'm not
Al completely ignorant, never tried to recondition a hi-fi before
though.

Al I'd appreciate any suggestions as to what to try, especially related
Al to the AU-101 in particular.

Al Thanks,

Al Alisdair

... A fail-safe circuit will destroy others.

Mark D. Zacharias wrote:
Smaller caps near a heat source, yes. Others, probably not.

Dirty controls & switches, number one.
Solder connections, number two.

Succinctly put, will do.

A tech could probably fix it in pretty short order. A do-it-yourself-er,
well, maybe, maybe not.

Well, I'll learn something, whichever way it goes. Thanks for the advice.

Alisdair

I previously wrote:
.....
I'd appreciate any suggestions as to what to try, especially related to
the AU-101 in particular.

In addition, my friend who gave me the amp has confessed that it worked
perfectly until he started using it as a guitar amp .... I suppose that
makes the problem more interesting.

Does this narrow it down any?

Thanks,

Alisdair

On Sun, 14 Sep 2003 14:57:01 +0100, Alisdair
wrote:

I previously wrote:
....
I'd appreciate any suggestions as to what to try, especially related to
the AU-101 in particular.

In addition, my friend who gave me the amp has confessed that it worked
perfectly until he started using it as a guitar amp .... I suppose that
makes the problem more interesting.

Does this narrow it down any?

One possibility is that he pushed it too hard, blew/fried a speaker,
which put too much of a load on one or both channels.

Tom


Thanks,

Alisdair