octave up?

[cmat]

I want to build an effect that duplicates my guitar 1 octave higher that harmonizes with my original note and I can adjust the volume of the wet signal.  Does GGG or tonepad have a board like this?

[gez]

This subject has come up many times and just about all that can be said on it is in the archives.  I don't mean this in a 'go F yourself' sort of way, just that there's a lot of good info there. 

[Mark Hammer]

The only DIY or other circuits I have seen which permits level-control of the octave-up are Anderton's Octave-Sounding Fuzz and Tim Escobedo's Oct-Up Blender 

The Anderton design splits the signal so that a straightforward TS-type fuzz comes in one mixing resistor, and a full-wave rectified (octave doubling) fuzz ciomes in the other mixing resistor.    Anderton's original circuit provides a level control for the octave up, but not for the straight fuzz, though the circuit is quite moddable.

Tim's Oct-Up sppits the signal into clean and octave fuzz, with mixing pots for each.

Somebody had the circuit posted.  I thought it was Stellan Lehrberg or Robin Tomtlund, but quick visits to their sites indicates its absence.  You can find Tim's designs here: http://www.geocities.com/tpe123/folkurban/fuzz/snippets.html   Check out the Ramblers too.

[Mark Hammer]

I forgot I had posted these:
http://img.photobucket.com/albums/v474/mhammer/AndertonOctaveFuzz.gif
http://img.photobucket.com/albums/v474/mhammer/ModifiedAndertonOctaveFuzz.gif

The second file was an idea in response to a request from someone.  I honestly forget what it was, but the second schematic adds a simple Boss transistor input buffer to relieve one of the op-amp sections of a quad or dual for a different duty.  The Blend pot alows mixing of an inverted or noninverted octave-up signal, and the Fuzz pot allos adjustment of the non-octave level, which the original couldn't do.  The original has a fixed fuzz gain and an input attenuator.  The modded version uses a variable gain instead.  The original does not have a feedback cap on the output stage.  I added that for noise/fizz control.

[jmusser]

I can personnally attest to Tim Escobedo's "Octup Blender" as being exacly what you're looking for. Go to the second page on "Links" at the bottom, to "Tim Escobedo Circuit Snippets". I don't know of anyone else who's even built it but me, but it is great sounding circuit, and a fairly simple build too. Let me know how you like it, if that's what you decide on.

[csmatt45]

Any chance there's a layout for the octup blender anywhere? Op amps still scare me a bit...

[jmusser]

I doubt very seriously that this has a layout. Like I said, it's sort of a sleeper in the DIY community, and I may have been the only one to have ever built it. As for the op amp, don't let that scare you. I can mark up a drawing for you with the pin outs and E Mail it to you so you can get your feet wet with them. Op amps are our friends! I believe I just used a Radio Shack LM324 quad op amp, but you could use a dual and a single, or a better quad like a TL074. The LM324 did a great job though. Just PM, and I'll help you in whatever way I can. One thing to note, is that this is not a clean sounding octave up. It has a very thick and eerie sounding fuzz. From what I can hear, once you dial out the dry boosted signal, and go to straight up octave fuzz, you also get the original buzzy squarewave fundamental blended in with the up octave fuzz. I love this things tone, and have yet to hear any other circuit that sounds like this one.