On Mon, 18 Aug 2008 09:28:55 +0100, "Arfa Daily"
put finger to keyboard and composed:


"Franc Zabkar" wrote in message
.. .
On Mon, 18 Aug 2008 00:56:26 +0100, "Arfa Daily"
put finger to keyboard and composed:

wrote in message
...
If I may ask first.

Would too high a voltage for the idling current on one of the channels
be a possible cause?

If you have been able to correct the bad idle current to the specified
value, the next thing that you should do is to compare the pot's set
position, or its resistance setting, to the pot on the good channel. If it
is near enough the same, then the most reasonable conclusion is that you
did
have a dicky pot, and rotating it has cleared the condition.

It stands to reason that rotating the pot fully CCW or CW should not
damage the amp, otherwise not many would have left the factory. If the
trimmer is wired as below, then why not measure the idling
voltage/current at both extremities and verify whether this trips the
relay?

|---|
| |
| V
--|-/\/\/\/\/\---

If neither setting causes the relay to trip, then the problem must lie
elsewhere.

- Franc Zabkar
--

Not disputing the "should" Franc, I was just thinking that if the pot was a
bit touchy, then whacking it from one end to the other with it farting
about, might just result in the magic smoke being released from the outputs.
Just being careful, which you, more than most on here, should appreciate is
a sensible thing to do with a DC coupled amp ... d;~}

Arfa

I was following up your suggestion that rotating a dicky pot may have
cured it, in which case returning it to its original condition would
not recreate the original fault. Furthermore, if the pot in the above
case had an intermittently open wiper, then you should be able to
reproduce the same fault by driving the wiper to the far left.

Based on the OP's followup, it appears that the pot itself may not
have been the problem.

- Franc Zabkar
--
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