I've always liked the H11L1. I think the most popular choice is the 6N138, however. Crow /**/ On Tue, 18 Nov 2003, greg montalbano wrote: > They say the mind is a terrible thing, and I can attest to that -- > trying all morning to remember what's being used these days in place of > the PC900 opto. for MIDI boards, and I'm drawing a blank. Any help?