Smoke is never a good sign, WA 88VA

[MarkL]

Sorry folks, I never seem to post unless there's a problem!

I had a red hot KT88 valve last year in one position in the right hand channel.

I fixed that with the forum's help - I replaced the pair of valves that side, and replaced the two 470R resistors and the two 47uf capacitors on that side.

Same valve position again, this time not glowing red hot, but smoke coming out of the amp. (But still working!)

The Mills resistor was toasted. Value intact. It was bright sunlight so I couldn't tell if the valve had glowed red hot. I replaced both valves that side, and replaced the 470R resistor.

It was 15mins before I got more smoke. The resistor is burnt, and it's value has changed.

I'm not sure where to look now for the source of the problem.

Any help would be much appreciated
many thanks
Mark