Integrated Amplifiers

While Denon rates the PMA-150H at 70W (into 4, not 8ohm) in practice it delivers slightly more at 2x44W/8ohm and 2x87W/4ohm. The Class D architecture means there's no appreciable dynamic headroom – the power remaining unchanged into 8 and 4ohm – with 145W available into 2ohm and limited by protection at exactly the same 145W/1ohm [see Graph 1, below]. Distortion climbs gently with output, levelling off at 0.007% from 1-20W/8ohm through bass and midrange but climbing quite significantly to 0.1%/5kHz, 0.25%/10kHz and 0.65%/20kHz (all 10W/8ohm). This is mirrored by the output impedance which also climbs at HF from 0.05ohm/1kHz to 1ohm/20kHz, and with the impact on frequency response discussed in our boxout. The A-wtd S/N ratio is above average at 87dB (re. 0dBW) and unwtd. hum low at –89dBV.

The partnering DCD-100 player is based around the popular Burr-Brown PCM5102A DAC and offers a generous 107dB A-wtd S/N from a maximum 1.94V output. The 850ohm source impedance is rather higher than I'd like to see, but distortion is consistently low at ~0.003-0.007% over the top 30dB of its dynamic range through bass and midrange [black trace, Graph 2], increasing to 0.008-0.03% at high (20kHz) frequencies [blue trace]. Digital jitter is close to the measurable limit for 16-bit CD at 124psec. The DAC chip offers both FIR and low-latency IIR filters, with Denon evidently opting for the former with its impressive 120dB stopband rejection traded for transient pre- and post-ringing on impulses. There's a slight ±0.05dB in-band ripple but the response merely dips to –0.1dB/20kHz and stereo separation is held to >85dB across the 20Hz-20kHz span. PM