Correct bias circuit

[glasman]

glasman wrote:

BTW, A nice little add is to put a small poly cap (.1uf or so) across the second cap to get rid of the HF stuff that can appear on some amps and to ensure that the bottom of the 220K's stay at AC ground.

Just to clarify, do you mean the cap that is connected to the bias pot wiper?

Thanks, Paul.

Yes, from the wiper to ground.

I normally use a 22uf ecap on the wiper to ground, and sometimes a .1uf to get keep everybody at AC ground.

Gary

[Guitarman18]

Many thanks, Gary.

[Funkalicousgroove]

Hi Funk,
What is the correct way to use your rectifier board in the assembly?
I found an old posting of yours that seems to have the rectifier board pretty much the same as the current pics you shared...
I couldn't see the 27k resistor on the board, but there appears to be a 'tail' resistor on the bias pot itself... I assume this is so you only have to route two wires from the bias/rectifier board.
Please see the attached pictures... two excerpts from your previous assembly drawings and the 'layout' proposed in the visio drawing that I've been posting... let me know if I've got it right!

Thanks,

As I remember, the 27K is grounded to the body of the pot. Gil or Brandon can correct me.

BTW, A nice little add is to put a small poly cap (.1uf or so) across the second cap to get rid of the HF stuff that can appear on some amps and to ensure that the bottom of the 220K's stay at AC ground.

Gary

on some it is, and some it ain't