Pre/Power Amplifiers

Unlike Primare's I15 [HFN Oct '18] integrated DAC/amplifier solution, where the analogue line input is sampled at 48kHz, the PRE35's balanced line in/out remains analogue throughout, as it does in the I35 [HFN Mar '19]. Distortion is just 0.00015-0.0016% (20Hz-20kHz, re. 0dBV), the A-wtd S/N a wide 96dB and response flat to within ±0.1dB from 10Hz-100kHz. Via its digital inputs the maximum safe volume position is '83' – the preamp clips at volume '84' and higher at 0dBFs – where the output is 11.7V (balanced) and distortion 0.0016-0.0068% (20Hz-20kHz re. 0dBFs). Distortion falls to a minimum of 0.0002% over the top 30dB of the PRE35's digital dynamic range [see Graph 2, below] where jitter is not entirely suppressed (440psec re. 48kFs) and its response scales with incoming sample rate, reaching –0.4dB/20kHz, –1.1dB/45kHz and –1.8dB/90kHz with 44.1/48kHz, 96kHz and 192kHz files, respectively.

The partnering A35.2 power amp builds on the performance of earlier UFPD amps, although its 215W/8ohm and 455W/4ohm power output is not substantially higher than that achieved by the older 150W-rated A34.2 amplifier [HFN May '15]. We have to go back to the Primare A60 [HFN Nov '14] before we find a bigger UFPD punch of 300W/ 575W (8/4ohm). Otherwise, the A35.2 still holds up well under dynamic conditions where it supplies 220W, 465W, 570W and 300W into 8ohm, 4ohm, 2ohm and 1ohm loads, respectively [see Graph 1, below]. Distortion increases from 0.0009% at 10W output to 0.009%/100W and 0.09% at the rated 200W (all 1kHz), and quite abruptly above 10kHz (0.04%/20kHz/10W) while the A-wtd S/N remains slightly below average at 79dB (re. 0dBW). PM