sifusteve

I wouldn't use another amp in the signal chain to the power amp in on the back panel. Using specifically a preamp pedal, or even a distortion pedal like a Boss Metal Zone has worked for me. Still have the presence and master volume of the power amp to play with. IMHO sounds better than the onboard DSP effects.

psarkissian, Thank you for your reply and answers. I have taken the processor board into my own work where I have SMT rework tools and a nice bench microscope. After reflowing almost all of the solder joints, replacing some electrolytics, performing a thorough cleaning with rubbing alcohol, placing a heatsink with thermal tape on the DSP and Codec chip, the board and amplifier seem to be working. I managed to play through it for about 1 hour without incident where before it would take only 10-15 minutes for the board to act up cease to work. Thanks for the advice and direction.

I managed to acquire a MK1 (I believe) Spidervalve 212 that I absolutely love. However, it appears as though the DSP chip may be failing and from what I gather may be unfixable. When it works, it sounds lovely. From what I can tell, the power amp stage looks good. I just replaced both preamp and power amp tubes with 12AX7 and a matched set of Sovtek 5881s. Biasing on the power tubes is ~32mV, and the amp has never been turned on without a speaker load. If the DSP board does fail, what options do you think I have? I would love to continue to use the power amp section of this device, but I want to do it correctly.