See below...

"Asimov" wrote in
message ...
"Engineer" bravely wrote to "All" (16 Jun 04 23:04:54)
--- on the heady topic of "Technics SA5160 distortion on one
channel"

En From: "Engineer"

En Greetings.
En I wonder if anyone has some insight into this problem.

(snip)

With a lot of obvious distortion a scope will just confirm it but it
could be useful to locate where it starts.

That was my plan.

If Pin 7 is the output to
the speakers then 0.20 volts on the left channel is certainly cause
enough for distortion.

Damn, that's a typo! It's actually 0.020 VDC, a bit less than the RH
channel.
I don't know the pin-out but I plan to measure the voltage across the
speaker termimals with and w/o a speaker connected, RH and LH
channels.

The +Vcc is also a little low compared to -Vcc.
This unbalance indicates the IC is sourcing significant current from
the positive supply into the speaker. Try and measure the same
voltage
without the speakers. If it goes way up then the IC could be bad.
However, a leaky coupling cap can also unbalance the IC or high ESR
can cause a parasitic oscillation though the latter isn't as likely.
Good luck and be careful!

Thanks.


A*s*i*m*o*v

... KPLA: Klingon Radio: All Klingon Opera, All The Time.

Cheers,

Roger