Graham, I don't know of anyone that plugs into the RCA plugs from the output of their arranger keyboards or synths. Most everyone that uses that input is using it for line output items, which is lower impedance at 1.5-vots DC.

I searched everywhere in the Internet and called Korg's customer service, but they said they didn't have an answer and would call me back. That was three hours ago. Nothing yet. I suspect this is the case, though.

Back to sippin' Margarettas.

Good luck,

Gary