This is fascinating. I have been a fan of the microsynth since it's introduction but never owned one until now, a second hand "XO" version I got yesterday.ecollins12 wrote:OK, I have figured it out. Thanks to reading the Stomboxology article. This is for the xo version...The transistor is basically a switch. The clean guitar is on the emitter. When turned on via the divided square wave, only half of the AC signal is passed. Kind of like a /2 sine wave. The jfet just buffers the signal which is then filter a bit by the 220nF cap. I was thrown off because the schematic has the sognal from the Jfet tied to square wave from the 4013, which i believe is NOT correct.
I have been completely mystified by the sound of the sub octave circuit. It actually seems to reproduce the tone of the input signal (i.e. pickup selection, etc) and even more bizarre, fret noises when sliding up or down the neck of the guitar. I've never heard anything like it that wasn't a DSP based "Harmonizer™" based pitch shifter, and certainly never thought this sound would come from a basic divider circuit.. it's really something else!
People describe the differences between the original versions and the XO in the sub octave, describing the original as more 'synth like" -- which is what you'd expect from the square wave derived output from a 4013 flip-flop. I'll take a look at the schematics here and elsewhere, but it's quite possible that the original input signal is being chopped by the divider output and added to the square wave.