So today I'm launching the OS-303 processor. This is the first open source u650 work alike for TB-303 and TR-606/TR-808 down the road. The code has a bit to go but the core framework is there. If anyone wants to contribute, get in touch since i have development kits available.
https://michigansynthworks.com/products/os-303
https://michigansynthworks.com/products/os-303
Also, today I'm launch my own 303 kit, LRB-303. This is a all SMD device where you only have to solder in 50 or so though hole parts. This thing is the result of 20+ years of building 303 clones so quite proud of the results (using all modern parts save the headphone amp and coil)
Cheers!
Raf
MSW