Transistorless Sound Synthesizer

I have decided to begin blending the Patrick oscillator and other circuits to the keyboard. The circuits are mounted and just need the interconnects added.

October 28, 2020 -  I am at a bit of a crossroads with this project. I will continue to explore just how much I can expand the range of sounds with this oscillator but now I also want to build a multi voice drone similar to what Sam from Look Mum No Computer fame has made at https://www.lookmumnocomputer.com/

If you have a moment then check out his projects. All are Mad Good but I really love the Drone of his and I think I can make at least a 5 to 10 voice example. Check out his Megadrone https://www.lookmumnocomputer.com/projects#/1000-oscillator-megadrone

And if I make a batch of oscillators then I could have a basic and messy polyphonic system in its beginning stages.

October 25, 2020 - Video of current tests of the LFO and perhaps make a Passive Optical Theremin

October 14, 2020 - First test scale using the very basic keyboard. I still need to add the sharp/flat keys but this taking shape.

October 14, 2020 -  Starting the layout of the tuning pots and keyboard switches.

Here is the basic circuit I am using. Pardon my poor sketch ;-)

October 13, 2020 - I found some very small switches in my junk box that will do for a small push button keyboard. Not ideal but good enough for testing. These were from a printer/copier that my landlord gave to me so why not make use of some of those parts. This will be a single octave from C2 through to C3 plus a extra key on the left for a knob controlled tone. Right now the oscillator has a hard time reaching C4 so going with the lower octave. Besides I love the deep rich sound this circuit has down there :-)

October 13, 2020 -  I have had this old TV tuner board in my junk box for about thirty years and I think these 20K pots will be of great use in the tuning of the keyboard part of this project. These pots take about 100 turns for full range. Very fine tuning indeed ;-)

October 11, 2020

This is just a sample of the deep low sound from the Patrick Oscillator. Very low frequencies and sounds great.