CRATE BV amp Ch1 prob- "Crunchy" Noises.

[Sea Chief]

Something happened after post 177-179.
Messing with C17 & grounding the V2 grids, you stated the noise ceased.
I am assuming that lifting the grounds would , at this point in time, make the amp noise.
It is not stated that this is true.
Post 179 you had a slight hum.
Since then you removed the Jfet (no noise) & reinstalled a new one.
And now?
Not even a hum?
I would check the wiring on the chassis & speaker.

Yes s'thing happened immediately prior to taking the JFET out, quite possibly, not neccessarily on taking it out (I see yr logic JP) as the 'proper quiet' I noted there (taking C17 leg up/ V2 pin 2 to gnd, & pin 7: both 'proper quiet').

As said I have checked chassis wiring over 3x. I have checked spkr wiring over 3x. These can catagorically be ruled out. There is some vv low hum I didnt even notice b4 form spkr, identical to when Pwr is switched on (& remains/ no change when Amp is turned on/ stby flipped) so spkr IS working, and reads 6.8ohms on its plug too.

[Jazz P Bass]

O/k then.
It's off to the new post.
http://music-electronics-forum.com/t34398/