using the octave section on the What The Fuzz circuit

[mordechai]

I was looking at the WTF project on the "Transistors and Beer" site and it looks great, but I'm wondering if the octave stage following the LM386 (an NPN/PNP pair of transistors going into two germanium diodes) will work if I were to isolate it and have it follow something like a Peppermill type circuit.  I like the idea of an octave overtone after a mild overdrive, but I am not sure what adjustments are necessary for this. 

[Earthscum]

Link to the project: http://www.forrestwhitesides.com/node/91 (helps out  )

The way to use this would be scrap it for a moment and check out Tim Escebedo's circuits HERE. Namely you're looking at the Pushme Pullyou. That is the basic breakdown of that circuit. The 386 in the WTF only acts as a driver, and you can replace it with about any gain stage that gives enough drive.

That help you out a bit?

The Octup! circuit (on the same page, Tim's circuits), does the same thing. I've found that if you drop the Source cap, you get almost perfectly clean octave at around unity. Could be useful to run before or after a distortion, or mix and add those overtones in clean mode. It is my personal favorite octave up circuit. 

[deadastronaut]

@david:  is that octup good on all the neck...or just up top?.

[Earthscum]

The octup had no form of "tracking issues" that I could hear. Power chords, complex chords, seemed to have that harmonic overtone. I have fun cutting the low end at about 72Hz before I feed bass into it and it starts sounding like a guitar. I was playing the guitar lines for "P*ss up a Rope" with my bass (warning... bad language).   What a weird feeling to me. Like trying to run the ice if I'm used to playing goalie.

[Mark Hammer]

Listening to the soundclip, it didn't appear to have strong octaving until you marched a bit up the fretboard.  A bit part of that is the extent of harmonic content for notes played lower down and higher up on the fretboard.  The shorter the string length, the stiffer the string, and the less harmonic content.  What allows octaves to be more robust is making the 1st harmonic (2x the fundamental) stand out more against all of that other original and doubled harmonic content.  The inclusion of a variable lowpass between the 386 and the doubling stage helps out, but not having played it, I can't tell by how much.