Primare PRE35/A35.2 Networked Pre/Power Amp Lab Report

Lab Report

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


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 17.3A


Distortion vs. digital signal level at 48kHz/24-bit via PRE35 preamp (1kHz, black; 20kHz, blue)

Continuous power (<1% THD, 8/4ohm) 215W / 455W
Dynamic power (<1% THD, 8/4/2/1ohm) 220W / 465W / 570W / 300W
Output impedance (20Hz–20kHz) 0.009–0.012ohm (180ohm, PRE35)
Freq. resp. (20Hz–20kHz/100kHz) +0.0 to –0.25dB/–5.9dB (A35.2)
Distortion (20Hz-20kHz, 0dBFs/0dBW) 0.0009–0.007%/0.0008-0.010%
A-wtd S/N ratio (re. 0dBFs/0dBW) 115.4dB (PRE35) / 79.0dB (A35.2)
Digital Jitter (48kHz/96kHz) 440psec / 155psec
Power consumption (idle/rated o/p) 25W / 450W (33W, PRE35)
Dimensions (WHD / Total weight) 430x106(145)x420(400)mm/ 23kg
Prices £2600-£3500 (pre)/£2700 (power)

Primare AB
Supplied by: Karma-AV Ltd, York
01423 358846