The Kawai & Teisco Analog Synths Group

I bought it new in '84, gigged with it a few years, got married, & just 
dug it out of storage a few months ago.  Of course the patch memory was 
gone, but amazingly the Ni-Cd battery hadn't leaked.  I replaced it, 
loaded the factory patches, & it fired right up!  It's in great shape, 
except for a sort of 'garbled' artifact in sounds with the filter 
somewhat stopped down.  If the filter cutoff is all the way open, it's 
not present.  Anybody have a PDF (or other form) of the service 
manual?  I'd be happy to send $ for your trouble...