AMPEG SVT-CL Unholy and Omnipresent Noise

[Kyuzo]

Hello all, I'm an EE but new to tubes, and I'm in love with my SVT-CL - but when I threw the switch at a gig last weekend I got an unholy hissing and crackling noise. My signal level was weak at any gain/master setting (but would occasionally punch through), and the red bias LEDS flashed on and off. I was able to rule out bass, all cables and cab by substitution. The noise is there whenever I come out of standby, even if gain and master are all the way down. Schematics are on the way and I'd love to work on this myself after I get some education on how to stay alive doing so...

Anybody have any insight? Should I give in and head for the shop? Is it time to spring for a SW emulator? Man, I love this amp...

Thanks for reading!

[Enzo]

With your bias lights flashing, it is time to consider it might need power tubes or at least a new 12AU7 or two.