Basic Math

Circuit consists of two transistor based drone oscillators tuned to different pitches. With a little experimenting and knowhow this could easily be turned into a working keyboard/piano. I'm pretty positive that this is how a lot of transistor organs function under the hood. 

 

Ambient Light Synthesizer

Similar to how the Atari Punk Console functions but his time controlling the oscillation with an LDR and the ambient/surrounding light. The drone is constant, even in a dark setting, but the more light the LDR receives the higher the pitch of the drone becomes. Another simple, fast, and rewarding build using the 555 timer IC.

 

Touch and Go

Another drone synth, but using the CD40106 this time. Really you could make a multi drone synth out of the same chip but I've already done that with the CD4093 design previously posted. This design uses a momentary switch to make/break the power connection to the circuit. The knob controls pitch. In the end you get a pretty fun little 'instrument' that requires very little parts to make. 

The Good, The Bad, The Ugly

Three oscillating drones from a single IC. The two first oscillators have a pretty wide range of frequency, while the third and final drone is substantially narrower. The pitches can be matched or pushed just slightly off balance with each other to create some really cool tones. This is a design pulled straight out of one of Nic Collins electronic experiments books. Not all 4093 chips are equal and I went through quite a few before settling on one that sounded good and behaved accordingly. 

Atari Punk Console

 A step generator circuit designed by Forrest Mims. Two oscillators give various tones capable of increasing/decreasing in equal "steps". This layout uses the 556 chip but it is possible to accomplish the same feat with two 555s. Forrest Mims is somewhat of a personal idol. He is/was just a regular guy like me without any real formal training who went on to have a successful career in electronics. Hes published several DIY books and journals and a lot of my work has directly stemmed from his projects.......just go check out his works.

Poorboy Pocket Piano

 A rather simple and rewarding “synthesizer” based off/around the infamous Atari Punk Console created by Forrest Mims. It more or less operates as a chromatic piano. This layout could also be frankensteined into a pseudo Stylophone type device with a little know how.