"Gilbert Bates" wrote in message
...
On Wed, 23 Aug 2006 13:05:18 GMT, " Dave xxxx"
wrote:

one or more output valves start glowing on and off like buggery,
loudspeakers drivers being thrown fully out and back again, loud pops.
this is happening with or without music playing



ta in advance


Dave


Leaky coupling cap? You could disconnect the power stage from the
driver stage by lifting out one end of a coupling cap and see if it
clears up...

If it is common to both channels, I would look to the psu or bias
supply.