Integrated Amplifiers

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