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previous: Mark Hammer Also important to note that one of ... -- 6/26/2000 6:23 PM View Thread

Re: Opinions on Octave Fuzz circuits

6/26/2000 8:48 PM
Re: Opinions on Octave Fuzz circuits
Mark, Ed--  
Thanks for the tips. I'll have to try bread-boarding it again, once I've finished the device below. Maybe I'll see about adding the octave bit to this box, to have an "all-in-one" unit....  
I already yanked everything out of the breadboard and built a close approximation of a Vox Suppa Tone Bender, which I think is pretty nice as a straight fuzz.  
Then, once I decided that I liked the basic tone of the beastie, I started adding stuff to it. So now it has an extra stage on the front end. Also, the stage just before the diode-feedback clip stage now has a direct coupled emitter follower attached to it and a nice switchable "twin-T" wah circuit (the one in RG Keen's "Tech of the Wah Wah" page) built around it for a bit of midrange focus to the obnoxious gain this thing produces.  
I think it sounds pretty cool. The wah circuit I borrowed for the wah stage has variable "Q" (a 1K pot as its emitter resistor), so you can control the peakiness of the mid boost as well as where it occurs. I had some problems with oscillation until I put in a fixed resistor to set the max "Q" for the filter. Now at the highest "Q" setting, you can hear the filter ring a little, but it doesn't oscillate.... Fun! :^)  
It adds a nice, focused midrangey sustain/feedback quality at lower "Q" settings (Santana in a box, sort-of), and can sound rather obnoxiously nasal at higher "Q" settings. It would also make a nice fuzz-wah pedal if I "remoted" the freq. pot.  
A SPST switch can bypass the filter section for full-bandwidth gain if you want, although the "Q" knob still affects the gain/distortion of the signal and having no negative feedback around the stage kicks the gain up a bit. I suppose a more complicated bypass switching arrangement for the filter section could accomplish a more "normal" bypass action.  
I've got a schematic of it to post, so I guess I should contact Aron....  
C ya,