I'm just laying out something similar but not as clever. Mine is a
simple mixer with reversible attenuators at the inputs. If you restrict
yourself to three inputs only, you can fit it into 1U wide. But the real
bummer is that I've only got the one bicolour LED. Damn, back to
drawing board.
Regards,
Tony Allgood Penrith, Cumbria, UK
http://www.techrepairs.freeserve.co.uk/projects.htm