This tremolo pedal relies on a photoresistor on the lid of the box to pass the signal to the amp. I used a strobing app on my phone flashing right on the photoresistor to control the tremolo effect. This was my first attempt at making one of these types of pedals. While cool, it’s not very convenient, since you have to have a light source to control the effect. It does, however, give you the ability to play around with the effect a bit more.
Testing the concept with Snap Circuits
The finished product