Four power amplifiers were used in the course of this evaluation: the Threshold S/550e, the Mark Levinson No.23.5, the Audio Research Classic 120 monoblocks, and the PS Audio 100 Delta. The preamplifier was the Rowland Consummate, and the CD player was the Wadia WT-3200 driving the Audio Research DAC1-20 converter. (CD was the primary source in this audition.)
Interconnects were AudioQuest Lapis between CD and preamp and for the unbalanced link between preamp and power amp with the ARC and PS Audio amps. For balanced hookup to the Threshold and Levinson…