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previous: Dan Lurie Trace,The Fat switch just adds ... -- 3/28/2004 7:47 PM	View Thread

Re: Fat + More Gain

3/28/2004 8:57 PM
Trace - Voodoo Amps	Re: Fat + More Gain ~~~ Trace, The Fat switch just adds a big cathode bypass cap to the preamp cathode bias. I want to increase gain more than just add the big cap so I thought if I lower the cathode resistor at the same time as add the big cap I would get there. The problem is as I stated above is the BUMP noise I get when I change the Bias level. @@@ You can wire in a 1.5K cathode to give you more gain and then use the switch to drop the cap (22uF) in parallel with the resistor. Off the top of my head I don't you are going to get around the bumping sound by the way you are switching. You would have to go to a different method of switching (more involved). Check out some of the multi channel amp schematics as they have several different ways of switching. Good luck and have fun tweaking! Trace

3/28/2004 8:57 PM

Trace - Voodoo Amps
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Re: Fat + More Gain

~~~ Trace,
The Fat switch just adds a big cathode bypass cap to the preamp cathode bias.
I want to increase gain more than just add the big cap so I thought if I lower the cathode resistor at the same time as add the big cap I would get there. The problem is as I stated above is the BUMP noise I get when I change the Bias level.

@@@ You can wire in a 1.5K cathode to give you more gain and then use the switch to drop the cap (22uF) in parallel with the resistor. Off the top of my head I don't you are going to get around the bumping sound by the way you are switching. You would have to go to a different method of switching (more involved). Check out some of the multi channel amp schematics as they have several different ways of switching.

Good luck and have fun tweaking!

Trace

Replies:

Dan Lurie I am using jFet's to switch so I co... -- 3/29/2004 12:18 AM