Tim's Octup Circuit?

[jmusser]

I've looked through the archives, and what very few people who have built this, haven't had any luck with it either. Has anyone built this, and actually got any up octave tone out of it? I think it would be a good time to go ahead and wring it out and see if us forumites can get it working. The schematic is at http://geocities.com/tpe123/folkurban/fuzz/snippets.html  The last time I fooled with it, all I could get out of it was overdrive. If you were to really smack the pick on the strings (Pete Townsend windmill), you would get an octave up during the smack, that immediately died away. I put a boost in the front to see if it just needed more umph up front, but that didn't help either. It uses an MPSA13 darlington up front, and a couple back to back non matched J201s. If anyone is interested in it, I can get some voltage readings from transistors etc. when I get home this evening, to give you something to work with. I feel that there's either some sort of design problem with it, or it's jusy very sensitive to the type of equipment that it'll work with. This one has been a puzzle to me, because I've built probably 2/3 of Tim's stuff, and it always worked as advertised. Yes, it is wired correctly, and the component values are correct. Any Takers?

[John Lyons]

Sounds good but after the XORUS and trying to get the gating to open up with even the Digital octaver fuzz...I'm pretty beat! I spent a lot of time there and didn't really end up with more than a headache, almost there but just a bitt too unstable...

Team work with some of the experts here should turn up the answers. Maybe Tim himself will chime in...

John

[jmusser]

Well, as you know, the XORUS is a thorn in my side, since it initially had so much magic, and I've never been able to achieve it again. Now, the DOF, I didn't have much problem with as far as being stable. It is a high pitched piercing tone that you can hardly play without ear plugs! The Octup looks like a more standard type of design approach than those two, and ought to be easier to figure out for the more technically oriented. It seems like whatever it takes to force the the bottom of the wave to flip up on top of the reference won't happen without some other piece in the puzzle.