iFi Audio iCAN Phantom Headphone Preamp Lab Report

Lab Report

While the Phantom's J-FET/triode topology is shared between the pre and headphone outputs, the latter does have its own output buffer that drops the (line) 73ohm source impedance down to 2.5ohm. This, in turn, limits the signal loss to 0.6dB into a 32ohm headphone load and restricts the impact of low/variable impedance loads on system (amp/headphone) frequency response. In 'solid-state' or 'tube' modes, the Phantom is flat to within a tight ±0.05dB from 20Hz-20kHz, declining gently to –0.2dB/100kHz but with a near-DC boost of +0.7dB/1Hz. Enabling 'XBass' invokes a tilt control operating below ~200Hz to provide a final boost of +10dB at 10Hz, 20Hz and 40Hz, respectively – its effect will not be subtle! The A-wtd S/N is a wide 101.9dB (re. 0dBV) via the balanced line or headphone output (98.5dB in 'tube' modes) while the low –99.5dBV/10.6µV residual noise ensures the iCAN Phantom is subjectively silent with high sensitivity in-ears.

The 0dB (–0.7dB), +9dB (+8.3dB) and +18dB (+17.9dB) gain settings are consistent via preamp and headphone outputs, although power output is influenced by gain to the tune of 1060mW to 2450mW and 2650mW/32ohm at 0dB, +9dB and +18dB, respectively. The maximum 10.0V output will sustain 167mW/600ohm and there's sufficient current to support a massive 5050mW (5.1W) into very low 8ohm loads [see Graph 1]. THD is impressively flat with frequency at 0.00013-0.00035% via the balanced line outs [black trace, Graph 2], increasing slightly at HF in 'tube' mode [blue trace], and through the midrange at 0.0008-0.0026% via the SE headphone outputs (0.001-0033% at 10mW/32ohm). Compared to the distortion incurred by even the best cans, these are still vanishingly low figures! PM


Power output vs. THD into 600ohm (black), 32ohm (pink) and low 8ohm (red) headphone loads


THD vs. frequency (preamp, black; tube, blue; headphone 0.6V unloaded, pink; 10mW/32ohm, red)

Maximum output (<1% THD) 20V (XLR, pre)/ 10V (SE, headph)
Power output (<1% THD, 600/32/8ohm) 167mW / 2650mW / 5050mW
Output Impedance (20Hz-20kHz) 2.5ohm (73ohm, preamp)
A-wtd S/N ratio (re. 0dBV/32ohm) 101.9dB / 98.9dB
Distortion (20Hz-20kHz, 0dBV) 0.00013–0.00035% (preamp)
Distortion (20Hz-20kHz, 10mW/32ohm) 0.0008–0.0026% (headphone)
Freq. resp. (20Hz-20kHz/100kHz) +0.03 to –0.05dB/–0.2dB
Power consumption 19W (1W standby)
Dimensions (WHD) / Weight 256x120x185mm / 4.2kg
Price £3749

iFi Audio
Supplied by: AMR/iFi Audio (Abbingdon Global Ltd), Southport
01704 543 858