Using dual SA100 mk3 in balanced, bridged mode (all XLR) with Genesis 350's (91dB) and passive (TVC) line stage, which also provides galvanic isolation. Dead quiet with ear right up to the speakers or amps. Also feeding them with balanced AC from a large (5KVA), centre-tapped, step-down transformer but, even straight from the wall, almost never had a noise problem. Most "natural" sounding amps I've owned.
Some noise when an active crossover (NHT X2) introduced between TVC and amps but that almost disappeared over time and is only a slight hum if I put my ear right up to midrange driver. Used the mute switch on the amps when not listening but always on and make nice quiet heaters over the winter. Gonna try another balanced AC transformer for the CDP and move it's small iso tranny to the xover.
Some noise when an active crossover (NHT X2) introduced between TVC and amps but that almost disappeared over time and is only a slight hum if I put my ear right up to midrange driver. Used the mute switch on the amps when not listening but always on and make nice quiet heaters over the winter. Gonna try another balanced AC transformer for the CDP and move it's small iso tranny to the xover.