Pro-Ject MaiA DS3 Integrated Amplifier Lab Report

Lab Report

This latest MaiA amp is also the beefiest of the series, meeting its rated spec. at 2x79W/8ohm and 2x145W/4ohm and holding enough in reserve to support 250W and 146W into 2 and 1ohm, respectively, under dynamic conditions [see Graph 1]. With these 'traditional' Class D implementations, both the 'continuous' and dynamic outputs are typically identical while the treble response is sensitive to the attached speaker load. For example, into 8ohm the response lifts to +0.6dB/20kHz and +2.4dB/43kHz, while into 4ohm it falls to –0.7dB/20kHz and into 2ohm to –3.3dB/20kHz. So, if the MaiA DS3 is paired with a speaker that has a rising HF impedance, it will sound brighter. Distortion, too, increases with frequency from 0.012%/1kHz to 0.65%/20kHz (re. 10W/8ohm), but the amp still has a good 86.7dB A-wtd S/N ratio (re. 0dBW).

Pro-Ject's implementation of the PCM1795 DAC is first-class, offering a 1.32V (fixed line) output from a 0dBFs digital input and with a wide 105dB A-wtd S/N ratio. Distortion climbs with frequency above the midband, from 0.00025-0.002% (1kHz-20kHz/0dBFs) and also increases linearly with decreasing digital level [see Graph 2]. Low-level resolution is good to within ±0.2dB over a 100dB range and jitter is fabulously low at ~12psec with 48kHz/24-bit data. A fairly standard, medium-tap linear FIR filter is employed with the PCM1795 DAC, combining a modest 65dB stopband rejection with a very flat response that reaches down below 5Hz up to 20kHz/+0.12dB (48kHz files), rolling off thereafter to 45kHz/–2.6dB (96kHz files) and 90kHz/–13.7dB (192kHz media). In practice, of course, it is the load-dependent response of the Class D amp modules that will define the 'tone' of this latest MaiA amplifier. PM


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 12.1A


Distortion vs. 24-bit digital signal level over a 120dB range, fixed line out (1kHz, black; 20kHz, blue)

Power output (<1% THD, 8/4ohm) 79W / 145W
Dynamic power (<1% THD, 8/4/2/1ohm) 79W / 145W / 250W / 146W
Output imp. (20Hz–20kHz/45kHz) 0.082-1.2ohm / 9.7ohm
Freq. resp. (20Hz–20kHz/100kHz) 0.1dB to +0.6dB/–6.6dB
Digital jitter (48kHz / 96kHz) 12psec / 35psec
A-wtd S/N ratio (DAC/Amp) 105.1dB (0dBFs) / 86.7dB (0dBW)
Distortion (DAC, 0dBFs/Amp, 10W) 0.00025-0.002% / 0.012-0.65%
Power consumption (Idle/Rated o/p) 11W / 179W (1W standby)
Dimensions (WHD) / Weight 206x71x252mm / 1.9kg
Price £1049

Pro-Ject Audio Systems
Supplied by: Henley Audio Ltd, UK
01235 511166