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Vintage threads from the first ten years

previous: Chris Hogan How would you do a post-PI volume c... -- 1/25/2000 2:42 AM

Re: "post PI" MV vs."pre PI"?

1/25/2000 4:44 AM
Todd	Re: "post PI" MV vs."pre PI"? If I remember the Ken Fischer article correctly, he removed the two similar resistors that fed off of the grid bias supply and replaced them with a dual pot. For example, in your standard Fender, the grid bias supply splits through two 220k-ohm resistors after the coupling caps, each going to a separate side of the PI output. Remove these resistors and replace with the dual pot in the 100k-ohm to 250k-ohm range depending on the amp. Don't quote me on this but I think that's all it takes. At full volume, the master volume should effectively be out of the circuit. TJK

1/25/2000 4:44 AM

Todd

Re: "post PI" MV vs."pre PI"?

If I remember the Ken Fischer article correctly,
he removed the two similar resistors that fed
off of the grid bias supply and replaced them
with a dual pot. For example, in your standard
Fender, the grid bias supply splits through
two 220k-ohm resistors after the coupling caps,
each going to a separate side of the PI
output. Remove these resistors and replace with
the dual pot in the 100k-ohm to 250k-ohm range
depending on the amp. Don't quote me on this
but I think that's all it takes. At full volume,
the master volume should effectively be out of
the circuit.
TJK

Replies:

Steve A. Todd: &n... -- 1/25/2000 9:01 AM