Vector-Wave synth kit from RYK Modular build and demo.
This is an all-in-one synth module with VCOs, LFOs, envelopes, filters, MIDI mods, and so on. A very deep unit, you should probably check their demo video after mine if you like it.
Not the easiest build. While all the surface mount parts are already installed, the solder pads for the LED matrix, jacks and buttons are VERY close to the surface mount parts, you need to be VERY careful with your soldering to not touch or short to those. The unit would benefit from more space.
Powerful unit as an all-in-one.

Build