Hi Mike;
I just finished building a recording studio in my basement. We have the Korg D1600 board chained to a Mackie 16 channel mixer as so not to take up all the inputs on the Korg. We've investigated the construction side to the proper wiring of a sound room. The info is unlimited. One problem we ran into was the proper wiring of extending the inputs to the next room for instruments. We used a 18ga twisted shielded cable for this. Seems to have eliminated static hum and noise. Also we grouped A/C separate from power. Another thing I've done is wrap some of the twisted cable in aluminum foil for addtional RFI and EMI protection. The only noise problem we've had so far was using my line6 212 spider amp. It's programing I belive is over driving or over gaining. I belive a DI box or like cannon mentioned using XLR. Y9ou could run a 16 channel snake into the instrument room possibly. Hope your project works out good, good luck.
~Ange
