M800 biasing and no sound

[Grazza]

Just finished an M800 build, photos attached. I have sound pass through when the effect is not on, however when I turn the effect on I have no sound. Maybe a switch problem, I thought I had continuity in the right places?
Also I can bias transistors 1, 2, 3 and 4 to within of 4.5V, however, not matter what I do with the trimpots for 5 and 6, they never change from 8.5ish Volts. 5 and 6 circled in red so you know which ones I mean. Please help, I was really looking forward to this one.

 

[music6000]

It's definitely got the JCM800 Gain available.
Did you try turning the Tone trimmer as that has a massive effect on the Sound, mine is at 9.00 O'clock if 7.00 is fully C.C.W.

 

[Grazza]

Yeah, thanks. I think I need to spend a little more time with that one

 

[music6000]

Yeah, thanks. I think I need to spend a little more time with that one

Now you have legit 201's, did you set them all to 4.5v to start with, then adjust them again as the they will go off voltage as you go through them!
With good J201's that I got, they are all set at 4.5v!, you can then adjust them a whisker one way or the other and the Gain will increase or decrease while you hit a chord for each trimmer you adjust one at a time!

 

[Grazza]

I did find that when I had initially all set them to 4.5v it sounded pretty good. Sometimes I wasn't sure if I was making it sound any better by messing with them