Pre/Power Amplifiers

Electrocompaniet's AW 300 M power amplifier, like its flagship AW 800 M , is rated at 300W/8ohm per channel. The latter is a (bridgeable) stereo amp while the amplifier under test here is a monoblock and its behaviour, to all intents and purposes, is almost identical to one channel - one power amp module - of the AW 800 M. Differences are slight and probably stem from small variations in the PSU and physical layout. So, while the AW 800 M broadly meets its spec. at 2x320W/8ohm and 2x580W/4ohm with 364W, 714W, 1352W and 1854W available under dynamic conditions into 8, 4, 2 and 1ohm loads, respectively, the AW 300 M delivers a mono 315W/8ohm and 565W/4ohm with a transient 352W, 690W, 1265W and 1825W into 8, 4, 2 and 1ohm loads (all re. 1kHz/10msec/<1% THD). The 1ohm figure is set by Electrocompaniet's over-current protection [see Graph 1] but the AW 300 M's 42.7A capability is more than sufficient to wrestle the toughest of speaker loads.

Distortion is a very low 0.00028% at 1W/8ohm and rises gently to 0.00039%/10W, 0.0009%/100W, 0.0017%/200W and 0.089% at the rated 300W (all re. 1kHz) while, versus frequency, the trend is very uniform, rising only gently at HF to 0.0016%/1W, 0.0033%/10W and 0.014%/100W [all re. 20kHz/8ohm - Graph 2].

Gain remains unchanged at a sensible 29.4dB and noise is very low, yielding an impressively wide 95.1dB A-wtd S/N ratio (re. 0dBW). Similarly, the response is flat to ±0.5dB limits from 1Hz-43kHz/8ohm but, again, the brand's claim for an exceptional >1000 damping factor is slightly optimistic. In practice, the 0.012-0.039ohm output impedance gives closer to >650 at bass frequencies - still good, provided you have thick cables! PM

Above: Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 42.7A

Above: Distortion Versus Frequency Versus Power Output (1W/8Ohm, Black; 10W, Pink; 100W, Red)

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