Hegel H600 Network-Attached Amp Lab Report

Lab Report

Hegel's dry wit is illustrated by the very precise '2x303W into 8ohm' specification for its H600, a figure met in practice at 2x315W and 2x600W into 8/4ohm, respectively. These numbers are largely unchanged from the outgoing H590 flagship [HFN Oct '18] as is its near-identical dynamic prowess of 327W/8ohm, 641W/4ohm, 1.24kW/2ohm and a huge 2.30kW (48A) into 1ohm [see Graph 1]. The +32.9dB gain is unchanged but despite this common 'gain/power' envelope, the H600 has been fettled for lower noise – and a wider 93.3dB A-wtd S/N ratio – alongside a very different distortion profile. The H600 has higher THD into lower loads, but the trend is otherwise very linear from 0.0057%/1W to 0.0045%/10W and to 0.003%/300W (all 1kHz/8ohm). THD increases slightly at LF (0.007%/20Hz) and HF (0.01%/20kHz/10W) with only a slight further increase up to 100W/8ohm. Response is flatter too – now just –0.11dB/20kHz to –0.8dB/100kHz/8ohm.

The H590's AKM AK4490 DAC is replaced by an ES9038Q2M converter on the H600's digital PCB, although Hegel's preferred choice of minimum phase filter type is retained, offering a 75dB stopband rejection with no (acausal) pre-ringing. Tested via the fixed (2.43V) line out, the response 'shape' shows a mild but consistent HF lift with all sample rates, reaching +0.2dB/20kHz, +0.75dB/45kHz and +1.7dB/90kHz (and +2.0dB/80kHz) with 48kHz, 96kHz and 192kHz media, respectively. THD is 0.0002-0.0013% (20Hz-20kHz) with peak (0dBFs) digital inputs and falls to a minimum of 0.00009-0.0004% over the top 30dB of its dynamic range [see Graph 2]. Again, the 107.3dB A-wtd S/N ratio is a marked improvement over the H590 and jitter is almost entirely suppressed to <5psec at all sample rates. PM


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 48.0A


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

Power output (<1% THD, 8/4ohm) 315W / 600W
Dynamic power (<1% THD, 8/4/2/1ohm) 327W / 641W / 1.24kW / 2.30kW
Output impedance (20Hz–20kHz) 0.027-0.058ohm (554ohm, pre)
Freq. resp. (20Hz–20kHz/100kHz) –0.15 to –0.11dB/–0.8dB
Digital jitter (S/PDIF at 48kHz/96kHz) <2psec / <5psec
A-wtd S/N ratio (re. 0dBW/0dBFs) 93.3dB (Analogue) / 107.2dB (Dig)
Distortion (20Hz-20kHz; 0dBW/0dBFs) 0.0045-0.013%/0.0002-0.0013%
Power consumption (idle/rated o/p) 85W / 1.014kW (1W standby)
Dimensions (WHD) / Weight 430x171x445mm / 22kg
Price £10,500

Hegel Music Systems AS
Oslo, Norway
Supplied by: Auden Distribution Ltd, Lancs
+47 22 605660