HiFi Rose RS201 E Streaming DAC/Amplifier Lab Report

Lab Report

Although HiFi Rose offers a slightly ambiguous 'max 100W' spec. for the RS201 E, the datasheet for Texas Instruments' TPA3244 PurePath Class D amplifier module suggests a figure of 50W/8ohm in bridged mode. This is realised in the RS201 E at 2x33W/8ohm and 2x60W/4ohm with the same achieved under dynamic conditions, increasing to 105W/2ohm and 100W/1ohm, all at <1% THD [see Graph 1]. Gain is sensibly modest at +28.6dB and the A-wtd S/N ratio above average for a Class D technology at 87.2dB (re. 0dBW). Distortion is very low at ~0.001% through the midrange at 1W/8ohm, increasing slightly to 0.0016%/10W, but rather more abruptly above 10kHz to 0.06%-0.3% at 20kHz from 1-10W. This is a function of the output filter network, as is the 0.08ohm source impedance, increasing to 2ohm/20kHz. The response is very load-dependent – at 20kHz it is +1.1dB/8ohm, –0.4dB/4ohm and –3.5dB/ 2ohm, so loudspeakers with a rising HF load will sound 'brighter'.

The RS201 E's ES9018K2M-based DAC/preamp stage is very 'clean', offering a wide 111dB A-wtd S/N ratio from a maximum 3.15V output and 165ohm source impedance (increasing to 345ohm/20Hz). There's some slight phase noise revealed by the jitter tests but correlated sidebands are suppressed to a very low <15psec (all sample rates). Resolution is good to within ±0.2dB over a full 100dB dynamic range and distortion falls from 0.00160.01% at 0dBFs (20kHz-20kHz) to a min. of 0.0003% over the top 30dB of its dynamic range [Graph 2]. The default digital filter is a standard linear phase type offering a 115dB stopband rejection with response(s) of –0.2dB/20kHz, –1.2dB/45kHz and –2.95dB/90kHz with 48kHz, 96kHz and 192kHz files, respectively. PM


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 10.0A


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

Continuous power (<1% THD, 8/4ohm) 33W / 60W
Dynamic power (<1% THD, 8/4/2/1ohm) 33W / 60W / 105W / 100W
Output imp. (20Hz–20kHz, Pre/Amp) 165-345ohm / 0.079-1.93ohm
Freq. resp. (20Hz–20kHz/100kHz) –0.0 to +1.1dB/–0.1dB
Digital jitter (S/PDIF / USB) <20psec / <10psec
A-wtd S/N ratio (DAC/Amp) 111.2dB (0dBFs) / 87.3dB (0dBW)
Distortion (DAC, 0dBFs/Amp, 10W) 0.0016-0.01%/0.0012-0.25%
Power consumption (Idle/Rated o/p) 14W / 90W (1W standby)
Dimensions (WHD) / Weight 278x76x202mm / 2.3kg
Price £1749

Citech Co., Ltd
South Korea
Supplied by: Henley Audio Ltd, UK
01235 511166