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previous: Craig I almost forgot to mention the main... -- 9/24/1997 2:40 PM

Re: ...I almost forgot...

9/25/1997 2:29 PM
Bruce C	Re: ...I almost forgot... The fact that you get no sound when you start out with preamp vol all the way up tells me that the problem is in the preamp. I bet if you set the preamp vol at 5 (just below the problem area at 6-7) then adjust the master vol, you will get no change in tone, only volume. Try this: run the preamp independantly from the power amp section, feeding it unto another amp off of the master vol control. If you get the same problem, you know it's in the preamp. If it is, try putting a 100k to 470k resistor feeding into the grid of one or more gain stages AFTER the peamp vol control. This solved a farting-out problem I had in a preamp I built. I put a 470k resistor between the preamp vol and the next grid - no more farting and no signal loss (due to the high impedence of the grid). Good luck!

9/25/1997 2:29 PM

Bruce C

Re: ...I almost forgot...

The fact that you get no sound when you start out with preamp vol all the way up tells me that the problem is in the preamp. I bet if you set the preamp vol at 5 (just below the problem area at 6-7) then adjust the master vol, you will get no change in tone, only volume.

Try this: run the preamp independantly from the power amp section, feeding it unto another amp off of the master vol control. If you get the same problem, you know it's in the preamp. If it is, try putting a 100k to 470k resistor feeding into the grid of one or more gain stages AFTER the peamp vol control. This solved a farting-out problem I had in a preamp I built. I put a 470k resistor between the preamp vol and the next grid - no more farting and no signal loss (due to the high impedence of the grid).

Good luck!

Replies:

John Greene Gary has the right idea of where to... -- 9/25/1997 5:10 PM