It's a special time to be around with so many synths and effects being programmed, designed and made by individuals - with some astonishingly sophisticated results. This DIY Poly Synth is a great example, made by the mysteriously named Chris Synths - featuring 8-voices, with two VCOs, a ladder-style lowpass and a state-variable highpass filter, wave folder, and ring modulation.
Here's a bit more detail taken from the video info:
All voice circuitry was made with op-amps, OTAs, and discrete components. There is one effect, an 8-stage analog phaser. There are two ST microcontrollers for MIDI, voice control, display driving, front panel scanning, etc. Control voltages are produced by 23 DACs, 21 DAC7554 and 2 AD5676. Circuit design and PCB layout was done in Eagle. PCBs made by JLC. Sheet metal designed in and ordered from emachineshop. Software written in C using STM32CubeIDE. Knobs and buttons are 3D-printed.
The wave folder is shown in his latest video:
There's also a video of his previous synth:
Very impressive stuff, I like the look of that X-Y controller! We look forward to seeing more.
And other stuff too...
PJ talks to Gaz
Track - Open and Empty
Mini Hydrasynth with Poly AT