Fred Briggs - E11even - Marshallesque Booster/Overdrive

Here's the schematic:

And here's the last in my series of Fender / Vox / Marshall themed boosters/overdrives - The "E11even" (Spinal Tap reference intentional). It's designed for those classic Marshall overdrive tones, plexi / jtm45 sort of stuff. It's based around the old mosfet booster design I love with a few tweaks. The bias control is essentailly a saturation control for those diodes, setting it high gives you more headroom and a smoother more spanky (hehe) overdrive, a lower setting gives a more gritty tone. The Body control allows you to alter the bass content and overall frequency gain structure of the circuit. When the body is at 470k you've got the classic Marshall mid/high boost filter (almost, with that 1M resistor to ground you don't quite get the same level of low end roll off but it works with this setup). One suggestion I have for a mod is placing the saturation control over one diode only so that you can dial in some really interesting (and extreme!) asymmetrical clipping structures...

For the protection diode you can use a 12v zener or just a red LED. I use a 470kB (linear taper) pot for the Body control but some may like the taper of a log pot here - it's up to you...