Integrated Amplifiers

The Pendulum might well be the most cost-effective D’Agostino amp on the block but, in practice, its technical ‘fingerprint’ has much in common with its very big brother, the Relentless 800 [HFN Jun ’24]. Overall gain, for example, is the same at +26.1dB and the response remains flat to near-DC, reaching out to –0.1dB/ 20kHz and –1.8dB/100kHz. That said, the output impedance is 10x higher than D’Agostino’s spec. at ~1ohm (production error?) so there will inevitably be some modification of this response into undulating speaker loads. However, while the Pendulum’s distortion generally increases with frequency – as expected – from 0.19% to 0.35% [re. 20Hz-20kHz at 10W/8ohm; see pink trace, Graph 2] it’s the unusual shift in distortion vs. power that marks out the family’s low-feedback DNA. As we saw in the ’800, the Pendulum’s minimum 0.12%/1kHz distortion occurs near full output [red trace] but is higher still at 0.16%/0.1W [grey trace] and 0.22-0.23% at 1-10W [black/pink traces]. Distortion also increases with decreasing load impedance, almost doubling with each halving of the load [see Graph 1] but, again, this might be expected from a low-feedback/high output impedance amplifier.

Whatever the parallels with the ’800, the Pendulum makes no claim to be as powerful, although even the rated 120W/ 8ohm and 240W/4ohm specification is not met in practice at 110W and 170W, respectively. It’s real mettle is seen under dynamic conditions where a very load-tolerant 126W, 215W, 349W and 434W is realised into 8, 4, 2 and 1ohm loads, respectively [see Graph 1]. This is equivalent to a maximum current of 21A (10msec at <1% THD) – very generous indeed for a ~100W amplifier and underpinning a beefy sound. PM