Roight, I have a JCM900 4100 head and, at some point next year, I'm gonna whack out the tubes - it currently has 4 Sovtek 5881's in the power amp and 3 Sovtek ECC83's in the pre-amp section.
So, I plan on replacing with JJ E34L's and ECC83's (instead of the 5881's) and I know that for the health/longevity of the amp and tubes, it should be rebiased too.
Now, a mate of mine is a total musical techhead and has apparently done this before on other amps and has managed to track down a schematic/plan/whatever for doing my amp. He's said he'll do it for free seeing as I can't find anyone locally who does this sort of thing.
Now, my question, does anyone have any plans so I can make sure he has good info to work off of. OR on a scale of 1-10, how difficult is it really to do this sort of thing and what happens if you do it wrong?
Cheers! :)
