> That's definitely a prototype (probably the very first one from 1993)
> because in the production series all potentiometers were pcb mounted. Even
> the later prototypes had pcb mounted potentiometers. It will be a problem to
> identify the trimming potentiometers as the positions and values may have
> been changed compared to the final version that is described in the service
> manual. I'm sorry but we have no records of this prototype as it's about 15
> years ago (the MS-404 has been developed in 1993).

Well, I suppose that makes it a collectable! I've just had another
fiddle with it and noticed the screw trimmer accessed through the hole
in the back of the case, the MIDI to CV scaling I believe, and this has
let me fix it. I don't think I've got it set exactly right but at least
it is not playing 13 semitones to the octave now!

Giles