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Hoffman Amps Forum image Author Topic: Bias vary tremelo speed and depth  (Read 2014 times)

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Offline Toxophilite

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Bias vary tremelo speed and depth
« on: April 14, 2018, 02:25:53 am »
HI I've adjusted one of these before but I've forgotten how and I couldn't find my old thread

I wonder if someone could remind me what i can do a 6G11 style bias vary treme to slow it down some
And also to cut some of the whoop whoop/depth
Thanks. This is for my stereo guitar amp build
Here's the schematic. i have a pretty high B+ for the trem , I'm not sure if that's a problem


It works, but slower and less whop whop would be great
This amp:

Offline tubenit

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Re: Bias vary tremelo speed and depth
« Reply #1 on: April 14, 2018, 06:26:47 am »
Did you look in ARCHIVES?

http://el34world.com/Forum/index.php?topic=604.0

With respect, Tubenit

Offline kagliostro

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« Last Edit: April 14, 2018, 07:16:04 am by kagliostro »
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Offline tubeswell

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Re: Bias vary tremelo speed and depth
« Reply #3 on: April 16, 2018, 04:10:14 am »
It works, but slower and less whop whop would be great


To slow it down, solder-tack a 0.01uF in parallel with the 0.02uF (to make 0.03uF) that is coming off the plate of V5a (LFO oscillator stage)


To reduce the thump, replace the 220k bleed-out resistor coming off the cathode of the V5b (trem buffer) stage with a bigger value; try 330k or 470k. Might take a bit of experimenting.
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