Cambridge Audio Edge A integrated amplifier Lab Report

I’m delighted to reveal that the Edge A integrated really does have the ‘edge’ on much of its competition. Rated at 100W/8ohm and 200W/4ohm it delivers 2x138W/8ohm and 2x234W/4ohm (a stiff +2.3dB increase in power) with sufficient in reserve to accommodate 150W, 290W, 520W and 670W into 8, 4, 2 and 1ohm under dynamic conditions at <1% THD [see Graph 1]. The field-cancelling toroidal transformers assist in the near elimination of hum while the A-wtd S/N ratio clocks in at a very wide 94dB (re. 0dBW) and 114dB (re. 100W/8ohm). The amp is DC-coupled but (sensibly) not flat to DC with –1dB points at 2Hz out to 80kHz (-0.13dB/20kHz), all served by a low 0.028ohm source impedance that rises slightly to 0.07ohm/20kHz before lifting to 0.63ohm/100kHz. Most impressive of all is the controlled linearity of the Edge A with distortion holding to a very steady 0.0003-0.0005% from 1-100W/8ohm through the midrange and from 0.00015-0.002% across the full 20Hz-20kHz audio range.

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Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 25.9A

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Distortion versus 24-bit digital signal level over a 120dB range at 1kHz (black) and 20kHz (blue)

The digital board is based on a tried-and-tested ES9018 DAC with a standard linear phase filter selected by Cambridge. Set to a 2V preamp output, it offers a vanishingly low 0.0002-0.0003% distortion (20Hz-20kHz, 0dBFs) with a minimum of 0.00012–0.0002% at –20dBFs [see Graph 2] and with response limits of –0.2dB/20kHz, –1.35dB/45kHz and –3.6dB/90kHz with 48kHz, 96kHz and 192kHz media, respectively. The A-wtd S/N ratio is a respectable 109dB and jitter lower than achieved with most outboard line-level DACs at <10psec across all sample rates. This is a remarkable performance for a DAC that’s integrated with a very powerful amp and situated adjacent to a large PSU. PM

Continuous power (<1% THD, 8/4ohm): 138W / 234W
Dynamic power (<1% THD, 8/4/2/1ohm): 150W / 290W / 520W / 670W
Output impedance (20Hz–20kHz): 0.028–0.070ohm (91ohm, pre)
Freq. resp. (20Hz–20kHz/100kHz): –0.0 to –0.13dB/–1.35dB
Digital jitter (S/PDIF at 48kHz/96kHz): <10psec / <10psec
A-wtd S/N ratio (re. 0dBW/0dBFs): 94.3dB (Analogue) / 109.1dB (Dig)
Dist. (20Hz-20kHz; 0dBW/–20dBFs): 0.0001–0.002%/0.00012–0.0002%
Power consumption (idle/rated o/p): 255-145W / 397W (1W standby)
Dimensions (WHD) / Weight: 460x150x405mm / 24.4kg
Price: £4500

COMPANY INFO
Cambridge Audio Ltd
PRC
Supplied by: Audio Partnership PLC, London
0203 514 1521
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