Archive of the former Yahoo!Groups mailing list: Yamaha CS80

Hi all.

Hope it's cooler where you live than here (southern California)!

I have a mystery for everyone. I just had a CS80 dropped off today
for a couple of (I hope) simple repairs. It's SN 13-somethings and in
pretty good shape and tuning. However, someone had previously
installed some kind of unison mod to it. The current owner was told
that it used to (many years ago) belong to Frank Zappa (Jobson era???).

I've opened it up a bit and taken a few pictures. They're in the
Photos section of the Yahoo group in album "Unison Mod." Does anyone
recognize this and/or know who did it? It seems to work.

When the lower switch is set to "U", the keyboard is in a dynamic
unison mode. Hitting one key stacks all 8 voices (sounds amazing!)
while hitting more keys starts splitting the voices. Hitting
additional keys doesn't send new triggers to the EGs, so it's like a
legato mode.

When the switch is set to "S" is seems to be in some kind of single
mode, in which new keys are assigned to upper or lower voice cards.
The upper switch somehow affects this assignment, but I haven't
figured out the algorithm yet.

I haven't lifted the keyboard yet, but I'll post pictures of the
mystery circuit board soon.

One thousand Quatloos to whomever can tell me about this thing.

David

p.s. CS80s are not fun to carry around in 95° heat!