I built this some years ago, and lost the ages on my blog so I thought I’d repost them. This was a idea posted by John Hollis, whatever happened to him?
Wired up this ampeg scrambler board I’ve had for a while. I’ve been trying to finish up all of the unfinished projects from the last few years.
Fired up first test. I used MPSA13 transistors. I got the PCB from John Lyons on DIYStompboxes. It’s the tone pad layout. The layout is set up for different transistor pin arrangements. The MPSA13s were working well, I was thinking to try some others before boxing this up.
Here’s an updated version of the octave fuzz. Q1 and Q2 set up a basic NPN Fuzz Face type circuit. While Q3 acts as a phase splitter. Q4 and Q5 act as a frequency doubler each side being fed an inverted signal from Q3.
So far the Fuzz section is working on the breadboard. The octave section is not working at the moment. I suspect the bias is off. Note the voltage around Q3. The collector and emitter voltages should be close to 4.5V. So far they are pretty far off.
This is an interesting distortion effect with an octave and wah like tone control. I redrew this schem from an issues of Stompboxology.
This is Tim Escobedo‘s Push Me Pull You. It’s an octave up with an interesting design. Using an NPN PNP pair.
This is design by John Hollis. It’s a booster that uses an inductor to generate a massive boost. It also has a switchable octave up. The boost sound is very warm and clear. The octave has a nice tone also.
There is a drop in volume between the octave and the boost, since the octave has to push the signal through a diode ring. This made it impractical to make the octave switchable with a foot switch. Hence the toggle.
I got the 3DPT toggle switches from FutureLec for a very reasonable price. I had to wait weeks for them. FutureLec is slow as mollasses, I would not recommend them if you are in a hurry.
This is a Green Ringer with both the filter mod and nulling mod. I found these mods at General Guitar Gadgets.
The filter mod filters the input signal to bring out a stronger octave. The nulling mod helps tune in the octave generated by balancing the signal on each half of the wave form.
The filter mod is switchable. With the switch on the octave is very pronounced. With an almost cartoonish character.
Here’s a drawing of the scehmatic that combines JC Maillet‘s nulling mod and Ben Milner‘s filter mod.
