Tweet
Have a Peavey VK100 with a intermittent noise in the preamp ..like a mini thunderstorm with white noise and "thumpy" type crackle .
At first I thought it was a pre tube gone noisy or the anode resistors but no, still did it with both tubes removed.
Double checked it by grounding the P.I. grid (quiet as a mouse).
Inserted a jack plug into the effects return thinking this will disconnect the pre
but noise was still there????
Used up the last of a can of freeze on the silicon components (fets, triac, transistor &
rev IC) with no discernible change and now of course its totally disapeared !
Noticed the reverb send is elevated approx 10v and the board seems slightly different from the diagram ie a 1 meg from pin 1 4560 rev IC.
Anyway reverb works fine and had the return turned down so the recovery half of
the rev 4560 is not the problem.
So now I'm thinking intermittent cap in the 14 v supply perhaps ...
Its certainly hard to remove the pre tubes !!!! Still hard even with a pink washing up
rubber glove (luckily no one saw me)..in the end I unscrewed the shield bases praying
there were no nuts underneath (there wern't!) .What were they thinking !
Any clues gratefully received meanwhile I'm off to get a new can of freeze and hoping it will return so I can get rid of it if you hear what I mean !!!!
At first I thought it was a pre tube gone noisy or the anode resistors but no, still did it with both tubes removed.
Double checked it by grounding the P.I. grid (quiet as a mouse).
Inserted a jack plug into the effects return thinking this will disconnect the pre
but noise was still there????
Used up the last of a can of freeze on the silicon components (fets, triac, transistor &
rev IC) with no discernible change and now of course its totally disapeared !
Noticed the reverb send is elevated approx 10v and the board seems slightly different from the diagram ie a 1 meg from pin 1 4560 rev IC.
Anyway reverb works fine and had the return turned down so the recovery half of
the rev 4560 is not the problem.
So now I'm thinking intermittent cap in the 14 v supply perhaps ...
Its certainly hard to remove the pre tubes !!!! Still hard even with a pink washing up
rubber glove (luckily no one saw me)..in the end I unscrewed the shield bases praying
there were no nuts underneath (there wern't!) .What were they thinking !
Any clues gratefully received meanwhile I'm off to get a new can of freeze and hoping it will return so I can get rid of it if you hear what I mean !!!!