I bought this to be a TB-303 sound alike. It sounds very close. The great thing (to me), is that it is _SO_ 303ish. No knobs send MIDI CC#. No parameters respond to MIDI CC#s. MIDI barely does anything on this box other than tell it what notes to play and when to stop making sound. THAT'S IT. A real 303 has no capability to sound as if it is velocity modulated, nor can the FB-383 - with the exception that it uses velocity data to determine if the ACCENT is on or off. Similar with glide, based upon the note sequence programming. So, the real TB-303 has a sequencer that only sends a small amount of data to the sound making section of it: when the note starts, what note it is, when the note ends, if the note is accented, and if the note is to be glided into from the previous. That is all the FB-383 listens to as well, nothing more.
Pair this box up with SEQ-303 and you get one killer combo! The SEQ-303 glide works perfectly with this unit.
Since this is a true analog circuit with dedicated knobs, the actual audio signal passes through the knobs. This may not seem like ground breaking data, but after just a few months of use my Cutoff knob started to get very noisey in one are of its travel. Now, after slightly more than a year of use, a second knob has started to make noise. I thought this noise would get burried in the mix - wrong. It is very obvious in the finished song.