via this listing This one is in via Chris. You can find some DIY builds and demos in previous posts here. These aren't too common. The last post was from 2018 and the first from 2006.

"Acidcode BassLine ML-303 analog synthesizer in perfect condition.
One of the best Roland TB-303 replicas in version 6. A classic among step sequencers and rarely available these days. All knobs, buttons, and switches work. Of course, you shouldn't turn it too far beyond its limit to avoid damaging it.
Only the delay knob is comparatively easier to turn, and the knob spins slightly. The delay knob itself works, though, so it doesn't matter if the knob continues to rotate at its limit. I might be able to find a replacement knob.
Firmware version: V7.02 July 08
Included in the offer are:
-Power supply
-1x MIDI red
-1x MIDI yellow
-Stereo 6.3mm jack to mono
-Mono 6.3mm jack
-Manual (printed version only)
Recommend this online Manual:
https://www.sequencer.de/files/ml303guide_user.pdf
For more information:
https://de.wikipedia.org/wiki/Roland_TB-303
https://www.sequencer.de/syns/roland/TB303.html
http://www.acidcode.de/"