The MAM (Music and More) MB33 MKII bass synth is a tb-303 clone (minus the sequencer) in a 19 inch rackmount format. It's shallow at about 4 inches.
Fully tested. It sounds great. Excellent for all kinds of bass and acid synth type duties. Very fat sub oscillator and distortion and filter full of character. This thing will burble and squelch and generate all kinds of nice bass tones. A gem that is ever more rare. Simple and fast to program.
This one is in nice shape, see pics. Works perfectly. Has external filter input for processing external sources as well as midi i/o.
Comes with the PSU
18dB filter just like the original TB-303. A new sub-oscillator was added and can be mixed with the other two waveforms for even meatier mono-bass sounds. A new distortion effect is also present and can be dialed-in to dirty things up - sounds great when resonated at high frequency cut-offs! MIDI can send/receive controls for the cutoff, resonance, ENV mod, accent, decay, distortion, and autoslide on/off.
Whereas the original MB 33 and Freebass 383 before it sounded very much the same as the TB-303, the newer MB 33 mkII adds even more possibilities for creating your own unique 303-like sounds - and at a fraction the cost of an original 303!
The link to the manual below is for the same synth that was made under a different name but works the same