ToneFreak Severe Distortion

Basically, a Marshall Guvnor derivative distortion pedal which is more similar of that from MI Audio's Crunchbox. Clipping is at the feedback loop of the opamp rather than shunting it to ground as seen in the latter.
A few notes:
- the VOLUME pot's Wiper(2) is the effect OUT.
- An SPDT with CENTER OFF toggle switch is used(this is much of a PRESENCE function similar to Crunchbox, only with a fixed 4.7K resistor). "center" pad refers to the CENTER pole of the toggle switch.
- CLIPPING selector switch, use an SPDT with CENTER OFF toggle switch same as mentioned above. Pads located between the 51pF cap and 10K resistor just above the opamp.
- Si refers to Silicon diode(i.e. 1N4148 or similar)
- Ge refers to Germanium diode(i.e. 1N34A, 1N60, etc)
- All SQUARE pads of the diode is the CATHODE.
- The 1M resistor beside the JUMPER, the 100pF and 2.2uF cap is actually 560K in actual SEVERE units.
- Leave the pads empty labeled as "LED" just above the 1N4001 protection diode.

There you have it!. Rawk on!.

Layout Download

Crunchbox v2 project

This is the crunchbox v2 of MI audio verified PCB layout. Added with Jack Orman's LED anti-pop circuit. http://www.muzique.com/lab/led.htm
Simple yet effective anti-pop circuit for true bypass pedals. Opamp is LM833 specifically from National Semiconductor but I use ST's version with excellent results. Try it!Remember to use IC socket.