" Dave xxxx" wrote in message
...
Keith G wrote:
" Dave xxxx" wrote in
message k...
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


Is this a stereo amp, if so are both channels playing up? Fixed or
cathode bias?

stereo amplifier and both speakers move


OK, how many valves per channel, how many of them glow and valve or ss
rectifier?

(Before you even answer, the one valve per channel in a SET is a blessing in
itself!! ;-)