Edwards Audio IA1 Integrated Amplifier Lab Report

Lab Report

While Talk Electronics' entry-level Edwards Audio IA1 is rated obliquely by the statement 'at its heart it has a 30W fully discrete class AB power amplifier section', in practice it manages a little less at 2x26W/8ohm and 2x39W/4ohm, the latter limited by electronic/relay-activated protection. But will the IA1 'sound' louder than this? In reality, yes, because under dynamic, music-like conditions there's sufficient reserve in the PSU to support 36W, 66W, 108W and 150W into 8, 4, 2 and 1ohm loads respectively (re. 1kHz/10msec/<1% THD). This is illustrated in Graph 1, below, along with the low 0.0025% distortion at 1W, increasing gently to 0.004% over the first 25W of its range. Distortion increases with decreasing load impedance – a not untypical behaviour – but still remains impressively consistent with increasing power output. Versus frequency there's the expected, but well governed, increase in THD at very low and high frequencies [see Graph 2], peaking at 0.035% at 1W and 0.08% at 10W (all re. 20kHz/8ohm).

The IA1's 0.02-0.08ohm output impedance maintains a response that's flat to within –1dB from 10Hz-22kHz/8ohm, rolling off (quite sensibly if used with DSD64 sources) to –11dB/100kHz. The plastic bonnet and fascia, while facilitating the option of different colours, is not as effective a screen as the traditional metal box! So residual noise is a moderate –65dBV and the A-wtd S/N ratio a very 'average' 85dB (re. 0dBW), all this from a full gain of +38.3dB, requiring 35mV to raise 1W/8ohm (0dBW). Finally, any DC offset is kept well under control at just 1-2mV, rounding off a very 'well sorted' performance from this compact but still fairly punchy integrated amplifier. PM


Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 12.2A


Distortion versus frequency at 1W/8ohm (black, 5Hz-40kHz) and 10W (red, 20Hz-20kHz)

Continuous power (<1% THD, 8/4ohm) 26W / 39W
Dynamic power (<1% THD, 8/4/2/1ohm) 36W / 66W / 108W / 150W
Output imp. (20Hz–20kHz/100kHz) 0.021–0.075ohm / 0.10ohm
Freq. resp. (20Hz–20kHz/100kHz) –0.3dB to –0.85dB / –11.1dB
Input sensitivity (for 0dBW/25W) 35mV / 175mV
A-wtd S/N ratio (re. 0dBW/25W) 85.0dB / 98.9dB
Distortion (20Hz-20kHz, 1W/10W) 0.003-0.035% / 0.022-0.080%
Power consumption (idle/rated o/p) 9W / 87W (1W standby)
Dimensions (WHD) / Weight 220x70x250mm / 3kg
Price £430

Talk Electronics Ltd
Wilts, UK
Supplied by: Talk Electronics Ltd
01344 844 204