> Also, what is a good depth? The synthesizers.com is 8.5" I see.
That's probably fine. Mine are a bit shallower than that, even.
> Do you always use rails to mount the modules, or is wood okay too?
I use wood. I haven't had any trouble with the threads wearing out, but I am
careful when I put screws back in, and I use high-quality square-drive wood
screws rather than cheap hardware-store screws. I personally don't see
enough advantages in metal rails to merit the expense, although it depends
on whether or not you like drilling lots of holes. :-)
> Is any cooling needed?
I use pegboard for the backs of my cabinets, on the assumption that it
provides some convective cooling while keeping out most of the dust. I don't
know whether "pegboard" translates well into your language. :-) It's
wood-like material about 5mm thick, made from some sort of compressed
fibers, with holes about 5mm in diameter every couple of cm. People
traditionally use it to hang tools on by attaching sheets to walls and
inserting pegs (actually hooks) into the holes.
> Are those also used in the original MOTM power supplies?
Yes, SynthTech uses Power One supplies.
--Adam