Simple Octave Up schematic

[Jdansti]

Socket your clipping diodes and you can try different combinations. If you use two of the same type you'll have symmetrical clipping. If you use two different types that have different forward voltages (for example one Ge and one Si) you'll get asymmetrical clipping which will sound different due to the different harmonics produced. You can also get asymmetrical clipping by placing two diodes in series in one direction and just one in the opposite direction. Be sure to try different LEDs as clipping diodes.

[buildafriend]

fun advice. thanks very much. I wired the booger up today. just tried a random transformer I had laying around that looked like it might fit the bill. it was a shot in the dark. no worky. transformer part number is tuo16 Im ordering the transformer and a few diodes right now. better luck next time.

I wish I had sockets but all my stuff is away in my friends shop at the moment. I couldnt even use a socket on the tlo71.

here comes the part where I get ripped off on some old germanium diodes.

[buildafriend]

hey, why is it that the schemo the OP posted has the xfrmr primary low going to ground but in the generalguitargadgets post it go's to +9v.

also; I found more info on the transformer. it sounds like more of a line level audio transformer...
                      Primary Secondary
Impedance     600ohm : 600ohm         
42TU016-RC

and heres the suggested one from the schematic;

Frequency response: 300Hz to 10kHz
1,000-ohm center-tapped primary
8-ohm secondary
Low-level impedance matching

[buildafriend]

alright, I swapped transformes and threw some Ge diodes in. It works great, and sounds great.

How could I make this thing shoot me up 2 octaves? 1 isnt cutting it for me. I'm guessing I could just change some cap values.

[slacker]

You guess wrong I'm afraid, you can't make it do two octaves up. The transformer and diodes make a full wave rectifier that is what doubles the frequency, no matter what you change about the rest of the circuit that's all it will do. Have a look here for an explanation of how it works, http://en.wikipedia.org/wiki/Rectifier#Full-wave_rectification its the same as the centre tapped version.

If you built two complete circuits and ran them in seriies, in theory you'd get two octaves up, it doesn't work great in practice though.

[buildafriend]

thanks.

[buildafriend]

I would think using a band pass filter that amplifies the 1st sideband/harminic would make more sense. this circuit is great but only really for soloing when you are high on the fret board. I don't like what happens when a chord is played.

I'm gonna play with using different op-amps and see what it does. maybe one will have more mojo. the bottom end disappears a bit too much for my liking.