I use balanced in and out on my SLP-05. My main source is a Marantz SA11-S2 CD/SACD player and my amps are Cary 211 AE monoblocks, all connncted via XLR's. This gives the lowest residual noise in the system and the sound quality is excellent. Two other sources that I very rarely use (a tuner and a cassette player) are connected via RCA's to the SLP-05 but I almost never use those sources.