Hey everyone, this is my second layout so all advice and corrections are appreciated. This is a Ross/DOD250/MXR+ type drive pedal with switchable soft and hard clipping, "fat" knob and a tone control.
There is an older version with switchable op amp and internal switches for LED clipping and fat boost. However, this is based on the final version (schematic drawn by member Bugg) VFE has hosted on their site:
http://vfepedals.com/schematics/distortion3.pdf All of their pedals have a relay switching system and charge pump, but based on what I gather from VFE head Peter Rutter's comments on the Alpha Dog (Rat clone) layout on the main page, it's straightforward. http://tagboardeffects.blogspot.com/2016/08/vfe-pedals-alpha-dog.html The clipping switches use W-taper pots for smooth transition, but I'm fine with the older method of toggle switches – as has been covered on the other VFE builds. It should work either way.
The protection diode, 100R and 100uf I added based on what I've picked up here, but please let me know if there's a better way, since they recommend using 18v on the original if you want.
Here is a clip of me playing into a clean amp and trying out some of the settings. It works the way you would expect silicon/germanium/bypass- hard/soft clipping to work with resulting level loss in some settings. I was able to get some heavy sounds, but it shines at carefully dialing in very smooth overdrive tones.