@yyzsantabarbara My Benchmark AHB2 power amp also supports professional level inputs. It allow choice of 3 gains 8.2dBu, 14,2dBu and 22dBu. The idea behind high level (22dBu) is to reduce gain of power amp. It provides twofold benefit - shifts gain into quieter environment (preamp) and makes cables more immune to noise (higher signal levels). I remember that long time ago the opposite was popular - low level inputs -10dBV = 0.316V. It seemed to be a good idea, since it saved money (gain in the amp only instead of gain in all connected equipment), but it eventually failed and today normal non-pro line level in US is 4dBu=1.23V. Benchmark recommends highest level settings and use of XLR only. They believe that with RCA you cannot get much higher than 16 bit. Benchmark AHB2 amp doesn’t even have unbalanced inputs, so I’m forced to use XLR. I bought the shortest (0.5m) high quality XLRs (Acoustic Zen Absolute). Perhaps it is an overkill to buy such pricey ICs for my modest system, but it is non-perishable item, that will stay with me forever.