Weird feedback---Crate

[Valvehead]

might also replace R1/2/3/4 and c1 while the board is out....one of those could be causing all the noise ?

[Valvehead]

ok...that didnt help...still has a lot of random static

could it be that opto device .. OC1 ?

[g1]

I've lost track a bit, originally there was oscillation but now there is static, correct?
Is it in both clean and drive channels?
When on clean, does turning down the volume get rid of the noise?
Have you tried a jumper from R1/R2 junction to ground? Does it make the noise stop?
If not, lift one end of C9, this will remove OC1 when on clean channel.