Pre/Power Amplifiers

The XSP-1 preamp may look ‘busy’ but at heart it’s a very clean design. Gain is about –0.7dB less than specification at +11.35dB (balanced in/out) and the volume scale shifted accordingly (so ‘0.0dB’ is –0.7dB, etc) but the 0.5dB increments are accurate. Noise is very low and the A-wtd S/N very wide at 101.7dB (re. 0dBV) while the response, in bypass mode, is flat to within ±0.3dB from 2Hz-100kHz. Distortion is very low at 0.00018-0.0005% (20Hz-20kHz, re. 0dBV) and some 10x lower than that offered by the partnering XPA-DR2 power amp at 0.004-0.006% [black vs. red traces, Graph 2 below]. The XSP-1 is good for a full 11V maximum balanced output but the source impedance is arguably a little high at 910-950ohm (20Hz-20kHz).

With its own claim to fame, Emotiva’s ‘Differential Reference’ XPA power amp offers exceptional watt-per-pound (dollar) value. Rated at 550W/8ohm and 800W/4ohm, in practice the XPA-DR2 delivers 2x650W and 2x1.02kW into 8/4ohm, the shared switch mode PSU maintaining an increased 765W and 1.27kW into 8/4ohm (one channel driven) and 800W, 1.38kW to 2.06kW into 8, 4 and 2ohm loads under dynamic conditions [see Graph 1]. Because the XPA-DR2 is a bridged design its amplifier modules ‘see’ half the real load impedance, hence it is protected at 255W/1ohm [which it ‘sees’ as 0.5ohm – green trace Graph 1]. Into 8ohm loads, distortion is well managed at 0.004%/1W to 0.007%/10W and 0.008%/100W before falling back to 0.004% at higher power prior to clipping (distortion is also very consistent across the 20Hz-20kHz audio range). Noise is exceptionally low and the A-wtd S/N wide at 94.5dB (re. 0dBW) while the response rolls gently away at HF to –0.4dB/20kHz and –5.1dB/100kHz. PM

Continuous power (<1% THD, 8/4ohm): 650W / 1.02kW
Dynamic power (<1% THD, 8/4/2/1ohm): 800W / 1.38kW / 2.06kW / 255W
Output imp. (20Hz–20kHz, pre/power): 945ohm / 0.032–0.070ohm
Freq. resp. (20Hz–100kHz, pre/power): +0.0 to –0.27dB / +0.0 to –5.1dB
Input sensitivity (for 0dBV/0dBW): 270mV (pre) / 90mV (power)
A-wtd S/N ratio (re. 0dBV/0dBW): 101.7dB (pre) / 94.5dB (power)
Distortion (20Hz-20kHz, 1V/10W): 0.0002–0.0005%/0.0038–0.006%
Power consump. (pre/idle/rated o/p): 21W / 40W/1700W
Dimensions (WHD, Pre/Power): 432x152x419/432x203x483mm
Prices (pre/power amp): £1419/£1750