Earth Sound Research Revival driver stage issue

[olddawg]

ALWAYS check the basing if transistors have been replaced in a previous attempted repair, especially if it's a sub. We have all been there.

[jvm]

Sorry, octal. I must have skimmed right over the second part because I knew I had replaced them with the same transistors that were in it. My bad, buddy! I surely appreciate the help from everyone on this. I continue to learn from everybody here!

[Goldstache]

I have one of the 50w same issue.
rebuilt all of PI stage. No dice.

Oddly, when I probe with DMM on resistance mode, black to chassis, red to low volt supply 20vdc (10k feeds) she turns on. Remove probe and HT to 100k’s drops to around where base/emitter are. With resistive measurement contact, 100k’s drop way less voltage and stages bias.

Any ideas???

hate to solder in my DMM to call it fixed.
ha
-joe

[Goldstache]

For reference.

stock: not passing
HT supply 100v (to 100k’s) about 22v on collectors.

with DMM dangling off of low supply side of 10k’s (base)
HT 100v (to 100k’s) about 60v once settled. And it passes and is an amp again.
Earlier in this thread the peavey variant was cited. Wondering if I should change section to that topology, and change the grounded grid side. Peavey used 10k’s no filter to ground. Earth ends up with about 1K and a filter.