Need a SUNN concert bass driver transformer or substitute

[s3156]

Any info on where to find a driver transformer for a Sunn concert bass head or what could be used to substitute for one?

[gbono]

Mercury Magnetics -- The Guitar Amp Transformer Company

why do you think it's damaged?

[s3156]

Hi, I can't seem to get any signal from the preamp to pass through it. No signal appears at the base of any of the output transistors. Any thoughts as to what else it could be?

[gbono]

So it appears that the preamp section works. What happens when you put a signal into the power amp input on the back panel? Are you getting correct DC voltages on the driver and output transistors? I believe the bases on the four output transistors are transformer coupled but the input transistors Q301, etc have no transformer connection - do you see a signal at the output of say Q302?