Mark Zacharias wrote in message
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"N_Cook" wrote in message
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Mark Zacharias wrote in message
...
"N_Cook" wrote in message
...



Yes, the timing certainly suggests this. At the end of the muting cycle, a
large DC bias is applied to the base or gate. With the drain or collector
sitting across the output to ground, this leaky transistor will then pass
DC
to the output. It has been a relatively common failure on Pioneer and
Yamaha
receivers, and I've seen it on Hafler preamps.

Mark Z.


not had time to power it up again , but no FETs in there BC550 and BC560
only.

Is there any recognised circuit supplemental to allow for the replacement
transistors going leaky over time?
I suppose 20 years before metalisation creep/migration re-occurs in the
replacement, is fair use.