"Mike Gilmour" wrote in message
...
Hiya Keith,

Nice thing about bottle gear, easy to spot the fault and get to. Seeing
R6
cooked (screen grid resistor?) why did it get mucho grid current I'm
thinking? It may be worth keeping an eye on it even if you've swapped out
the tube. But I think possibly that coupling cap was leaky giving +ve to
G1
driving plate current hard and screen grid current burning R6 - Good job
Keith you've got the problem all sorted for Crimbo :-)
Cheers,

Mike



Hi Mike,

Well, fingers crossed, it's been running for 6 hours straight now and no
sign of overheating. (Room's like an oven, of course!)

I'm blaming the Czech KT88s arcing over for the two instances I've had of a
brew-up with this amp in the last two years, but I'm always eager to learn,
if you think there might another likely cause of this problem I would be
very interested to hear it. Personally, I think it's a sussy little bugger
(Kit88) anyway because WAD didn't keep it on the books for long - superb
sound quality but possibly not too stable? (I really ought to get on to the
WAD forum and see what the 'word on the street' is!)

Don't know what anyone else here might think of a KT88/6550C comparison but
it seems the bass is even more thunderous than it was??? (It ain't got the
biggest OPTs in the world but it's never been too 'polite'.....!!)

(Btw, we're on holiday now so might finally get round to that Black Isle
proggie we've got recorded! :-)