VHT amp problem

[Valvehead]

I have a CL-100 head here. It has a constant static/crackling noise . It does not do this on the Clean ch. Only on the 2 dirty channels.

I know you cant get scems for VHT's , so Im in the dark here.

When i pull the 3rd pretube-its silent. when i pull one of the pretubes next to the FX loop circuit (labeled V101) --its silent. The other pretubes dont really affect the noise.

So I know its somewhere in the loop ? or near V3.



I dont know this circuit but i do get strange readings on the 2 pretubes near the Loop circuit (these 2 are on the power tube board) .

pin 2 200mv , pin 7 47V

pin 2 36V , pin 7 36V



also on V3 (3rd pretube) i get 32V at pin 7 .



maybe this is normal in these amps ?

also , with the Loop on, i can turn the loop level pot and it DOES affect the static , so when the level is all the way down = no noise.


anyone been servicing these or have a schematic ?

I have swapped out all the pretubes and that didnt help. also cleaned all jacks and pots

[techineer]

No schemo here, but I have found the folks at VHT to be fairly cooperative at helping me solve problems on amps I've had in here.

Those amps are well built, and would be nearly perfect if the manufacturer would provide service data support.

[Valvehead]

ok, i guess i will try and call them