Keith G wrote:


OK - powered up with dummy loads.

Grid to Ground:

Good Amp - a *continually* changing 0.04 to 0.06 VDC

Bad Amp - steady 202 VDC (???)

Are we on the money so soon?



Looks likely.

220uf seems to be a odd value coupling cap, I would have expected 0.22uf
or so. Looking at the picture, I would have thoulf what looks like a big
PIO would be the chap.

BTW, if its 0v, and you have a cathode resistor, then it will be cahode
bias (I would expect)

Track down the coupling cap and remove/replace it. Any old 0.22uf cap
will do to try, as long as its got a voltage rating of 500v or more.

--
Nick