This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Friday, December 11, 2015

FuzzHugger FX Phantom Octave

The Phantom Octave is an octave/ring mod type fuzz that's very interactive with guitar pickup selection and volume/tone controls. The LED pads are for the one that's under the knob in the video below. You could use it as the on/off indicator, but it might be hard to tell if it's on when signal isn't passing through it. Should be able to squeeze it in a 1590A. From the manufacturer:

Equal parts mysterious and ghastly, the Phantom Octave is a shape-shifting octave fuzz 
monster! No controls? They're not necessary--they're at your fingertips! The Phantom Octave is 
extremely interactive with your pickup selection, picking intensity, and your guitar's Tone 
control. Like its namesake, the octave will disappear with picking intensity and by rolling back 
your guitar's Tone control. Octave effect is strongest with low-output single coil pickups.


  1. Hi, built this tonight and im getting nothing from the circuit. No noise nothing.

  2. Hi, I built this and it didn't work properly, not much/any? octave and the light not lighting up. I made the circuit again on the bread board and found I got better results if the diode going to pin 2 was the other way round. The light works and there is a clear octave down. Could the diode in the layout be backwards?

  3. I found another layout that had the diode to ground the other way around? I'll check this out tomorrow but maybe that does the same thing?

    1. Yeah, this is probably the culprit. The diode above the 47k resistor should be flipped. Just fixed that in the layout.

    2. ok I tried that. With the two diodes that way round the led also needs to switched round positive side to ground.

    3. So with the led swapped round the layout works perfectly, flashing light, sub octave, fuzz. It's a great fuzz for beginners I think. I haven't seen any easier sub octave circuits. I also like it wit a clear led, so I will probably put a switch in for two leds.

    4. Cool. Here's the schematic for reference.

    5. This comment has been removed by the author.

    6. Thanks I have been looking for a schematic but couldn't find one. Someone over at diy kindly drew one, and I drew another to change the diodes.
      Which is here
      My one does have the led the other way round and that's what I think I've got working. I will check again to be sure, but I don't suppose it really matters because the LED is off-board any way.