I made a phantom octave... But I ain't got no octave

Started by jdoughty, December 17, 2020, 12:15:09 AM

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jdoughty

Building this:
http://effectslayouts.blogspot.com/2015/12/fuzzhugger-fx-phantom-octave.html?m=1

The circuit produces a fuzz tone, however no glitchy octave effect. I've used an audio probe and I can hear signal through out, but it never gets glitchy
Voltages:
P:9.3
1: 1.3
2: goes from 20 to 50 randomly
3: 0
4: 0
5: 4
6: 8.4
7: 4.3
8: 1.3

iainpunk

that's one super sketchy design! (just like some early fuzzes)
i don't think that its supposed to generate an octave up, despite them claiming that.
did you play on the neck pickup with the tone all the way down?
have you tried a 100k resistor between pins 2 and 3? that might help the stability on pin 2. if you socketed the chip, you can probably just push it in place to try out and if it works solder permanently later.

cheers, Iain
friendly reminder: all holes are positive and have negative weight, despite not being there.

cheers

jdoughty

https://youtu.be/AutYOmYnDPY here's the intended effect. It's equal parts modulation, octave, and fuzz. I'll try the resistor here in a bit and see if it helps.

I forgot to mention that I've now flipped the LED that's on the circuit. No difference, but it seemed backwards to have the positive hit the ground

Kevin Mitchell

#3
You'd be surprised how often octave circuits have minimum or no effect to the guitar signal. In most cases from my experience, it depends on the guitar you use and how hot the pickups are. For that reason I've notice humbuckers are great for low octaves while single coil pickups bring out the high octaves a bit better. Where you're playing on the neck is another variable.

Not saying that's the issue - just something to consider. Analog octave effects can be a pain and usually takes a little extra work to get what you want out of it.

I've never seen that octave circuit. In fact, all analog octave down circuits I've seen use a CD4013 chip. So that one may be a little more picky than you'd expect.

Sorry if that isn't helpful  :P
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