i've good and bad about the advent outboard units, but they seem to be the dolby decoder most used. i have a 100A myself, which seems to have given up the ghost so i'm prowling for another.
just thought that i'd pass on that there is a fellow on ebay with 7 of them for sale. a bit overpriced when shopping for one, but i'm wondering if getting a selection would be a good way to assemble one set of working cards...
anyway, FYI if for nothing else.