Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Toxophilite on April 14, 2018, 02:25:53 am

Title: Bias vary tremelo speed and depth
Post by: Toxophilite 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:

Title: Re: Bias vary tremelo speed and depth
Post by: tubenit 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

Title: Re: Bias vary tremelo speed and depth
Post by: kagliostro on April 14, 2018, 07:13:42 am

http://el34world.com/Forum/index.php?topic=19125.msg196509#msg196509 (http://el34world.com/Forum/index.php?topic=19125.msg196509#msg196509)

http://el34world.com/Forum/index.php?topic=18529.msg200251#msg200251 (http://el34world.com/Forum/index.php?topic=18529.msg200251#msg200251)

Ciao

Franco

Title: Re: Bias vary tremelo speed and depth
Post by: tubeswell on April 16, 2018, 04:10:14 am

Quote from: Toxophilite on April 14, 2018, 02:25:53 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.