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Hi folks,

I own the Dunlop Jimi Hendrix Octavio Fuzz LTD (JHM6) and I love this pedal to pieces.
However, sometimes the octave up ist a little too much for me.
I'd like to mod it with a switch that basically turns off the octave.
I know that there's the Fulltone Octafuzz which has a switch like that and the schematics seem similar.

Has anyone done a mod like that?



If I understand correctly, the transformer is responsible for the octave up. I've seen other schematics having a switch somewhere on the output side of the transformer, right between one of the diodes and connector 3 of the Volume pot.
However, this doesn't make sense to me, yet.
Why would cutting one of the transformer outputs disable the octave?

Any hint appreciated.

houserockr wrote: Why would cutting one of the transformer outputs disable the octave?

Full wave rectification effectively doubles the frequency.
Limiting full wave rectification to half wave rectificaton is your hint.

Right, I remember now.
A rectifier basically flips/mirrors all negative parts of the sine wave to the positive and thus doubles the amount of wave peaks and thus the freq.
The part I don't understand is how the diodes are oriented in the schematic.
1.) I remember a rectifier having 4 diodes and
2.) What confuses me is the fact that the two diodes in the octavio have the same direction

houserockr wrote:Right, I remember now.
A rectifier basically flips/mirrors all negative parts of the sine wave to the positive and thus doubles the amount of wave peaks and thus the freq.
The part I don't understand is how the diodes are oriented in the schematic.
1.) I remember a rectifier having 4 diodes and
2.) What confuses me is the fact that the two diodes in the octavio have the same direction

It uses transformer with a center tap. For a pretty good reason.
That's why it needs only 2 diodes for a full wave rectification, unlike transformers w/o center tap.

I made the one I built switchable, also found some NPN germanium transistors so it sounds better as a fuzz.