Hi Bill, Looks like wiring through a cap is the way to go. I found this existing thread. It is not easy to make full sense of it as it is: http://launch.groups.yahoo.com/group/korgpolyex/messages/311?threaded=1&m=e&var=1&tidx=1
Message
Re: External Audio in Mod.
2011-07-18 by 7yash