EHX Nano Small Stone Mods
I have the surface-mount filled nano Small Stone, which makes it very difficult to mod. When I opened it up, this is what I saw:
I thought, OK I'll do the vibrato switch, I only have to desolder a resistor. So I started comparing it to the schematic. It's nothing like it. In the nano small stone, there are no transistors, two opamp, two surface mount diodes, around 5 electrolytic caps, and many of the resistors have values like 27.4k or 392k. Tracing is impossible as the board is double-sided and many of the traces go under components. I quickly realized that any existing mods would be useless because I wouldn't be able to tell where to do them and because I wouldn't be able to solder them anyway. So I focused on making mods on the things I could solder to: the pot, the electrolytic caps, the jacks, and the 3PDT switch, and I found a great mod the lets you select sine, reverse sawtooth, or sawtooth LFO waves.
The sawtooth and reverse sawtooth modes are nice for having a more rhythmic sweep, more pulsating than swooshing. They are both faster than sine. I don't know if this would work for Small Stones other than the nano. Someone with a big Small Stone should try it out.
Because of the shape of the PCB, the switch would have to be installed like this:
Here's a wiring diagram:
Bypass - Normal (Sine) - Sawtooth - Reverse Sawtooth