Artists use this
Best TB-303 clone is actually a replica ...
This one is in my ears the best sounding 303 machine that is not the original TB-303. Mine was built by Andreas Kump aka "Kumptronics" in Austria and has a special full metal case with blue coverplate. It has the "945p" transistors inside and is calibrated "rough".
I have the version with a TT303 case, so I can use it with batteries instead the ALU case.
The DinSync is a DIY project to build your own TB303. There aluminium cases and plastic case like the TT303 (MK1) case Please note this is a replica not a clone. Al parts are the same as TB303. The RE-303 (CPU) supports MIDI in- en MIDI out and have also the DIN in/out. When your own TB303 is broken you can repair it with DInSync parts. Even you can use the TB303 CPU when you have one or when your TB303 CPU is broken you can use the RE-303 CPU including MIDI.