Sparkle Drive "Clean" knob

[Kearns892]

For those of you who have seen this pedal, you probably know that the "clean" knob is really what makes this pedal different from any other Tube Screamer based OD. I really liked the idea and want to build one, but also understand the workings behind the "clean" knob, because I could see it having a wide range of uses in other pedals. So I was wondering if there was anyone out there who would help me (a stompboxing noob) out by posting a schematic and pointing out and explaining the part that the "clean" knob works from, as well as any theory on applying the concept to other types of pedals.

[jlullo]

i'm not 100% sure, but i believe that the "clean" knob is just a clean blend.  can anyone confirm this?

[tackleberry]

Sounds like what it is just a blend between the clean boost side and OD side. Theres an old maestro pedal with this, a dual gang pot that blended a clean boost and fuzz.

[Kearns892]

Right, I was wondering if anyone could work me through how the actual circuitry works to achieve that effect though. Sorry I should have been more specific.

[Alex C]

Here's a link to the schematic that I've seen floating around for awhile:
http://home.hetnet.nl/~chrisdus/download/VLSD.jpg

I know that clean blend circuits are implemented in several other effects; bass overdrive/distortion units come to mind.

[Mark Hammer]

Actually, Craig Anderton and PAiA did this well before Voodoo Labs: http://experimentalistsanonymous.com/diy/Schematics/Distortion%20Boost%20and%20Overdrive/Axe%20Grinder.pdf

[Kearns892]

Thanks a lot Mark, I can't wait to try to incorporate this into something.