Stereo tremolo / ping pong / auto panner. The board will fit easily in a 125b with 2 inputs, two outputs, power jack, and maybe even a switched jack to control rate with an expression pedal. Refer to the schematic as you can use switched jacks for inputs. You may have to use your imagination for bypass. I've used a couple relays so I can bypass and get LED indication. If you're not worried about an LED you can use a 4pdt switch. I've added extra filtering and pulldown resistors which can be omitted if you desire. I've also added a few ferrite beads marked FB, which can be replaced with jumpers if you prefer. If you're using an LED & LDR make sure to wrap them together with heat shrink or something. You may want to try and match parts there for best results. Enjoy!
Schematic from GGG: http://generalguitargadgets.com/pdf/ggg_catremst_sc.pdf
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