Optical Theremin Kit

My son and I finished assembly last weekend. We got the kit for a school assignment. It works well- great for $30 but does not exactly sound like a (much more expensive) real theremin. The instructions are online only, and they presume a decent level of technical reading experience. I tried to breadboard the circuit based on the circuit board but couldn't get it to work so we just followed the instructions and soldered it. We went with the stereo headphone Jack as an output- it's included in the contents but not in the instructions. I had to read the circuit diagram to figure out where to ground it as it was not mentioned in the instructions. We hooked it to a guitar amp we had and it sounds pretty good. Some of the soldering points are a little tight for a novice, 2-3 millimeters apart, which is why I wanted to breadboard it- to make sure it worked before I accidentally shorted something. I'm pretty novice when it comes to this stuff so it was a challenge but it was fun. I haven't done anything like this for about 2 decades- since intro to electronics in high school. Honestly it took us about 5 hours to complete but we didn't rush it and had fun and my son got an A for the project.