The Beam Catcher is my first foray into making a very formal synthesizer, one I can sell and reproduce reliably with a PCB. While I'm no stranger to PCBs, I typically go with paper circuits and stripboards for my creations, as I'm usually the only one using and maintenancing them.

The Beam Catcher is a 12 oscillator, analog synthesizer utilizing two CD40106 chips as oscillator banks to drive twelve LEDs. It has a trimmer to tune each oscillator, which have a range of 14hz to >10khz.

The idea was conceived in a conversation with my friend Tob after we talked to the Passepartout Duo and saw their Chromaplane prototype in action.
Tob had recently just showed me his light demodulator and how you could get crazy sounds out of it from the PWM of LED signs outside of businesses, so in our conversation about the instrument the natural progression was taking the chromaplane's concept and adapting it to the context of light energy. After this conversation, I quickly took to making a prototype, and within the few days I had a cardboard proof of concept (pictured right).

Well, it's pretty simple, all you need is two mono (stereo works too) aux cords to plug into the sensors, and a pair of headphones or other equipment to plug the stereo aux output (center jack) into. The closer you bring the sensor to the LEDs, the louder it gets. Another thing to keep in mind is the angles. The farther you get from the LEDs, the more crossover of notes there is, which allows you to play chords and play less precisely. Also, the straighter the angle between the LEDs and the sensor, the louder it will be.

For the best sound quality, I recommend using the beam catcher with a shielded aux cables and a "clean" USB power supply, in my experience samsung USB wall adapters work well.

The Beam Catcher is now available on Etsy! You can find my etsy here. Also here's the github.

You can build them yourself! It's quite simple, all you need is a clear photodiode sensor and a 3.5mm mono (or stereo) auxiliary jack. The easiest place to source these would be ebay or aliexpress. Just solder the short leg of the photodiode to ground and the long leg to the signal pin (left channel if it's a stereo jack).