Luxman P-750u headphone amplifier Lab Report
Furthermore, the P-750u’s output impedance remains so usefully low at ~500mohm that there will be little variation in system response with the varying load of different headphones – reaching down to –0.5dB points of 2Hz-32kHz whether loaded or unloaded. The same is true of distortion, already 10x lower than Luxman’s specification at 0.0005-0.009% from 20Hz-20kHz at 10mW/25ohm or 0dBV/47kohm [see Graph 2]. As further testament to the efficacy of the LECUA volume regime (and the dual-mono layout), channel balance is true to within 0.05dB over its top 70dB dynamic range and channel separation is >90dB re. 0dBV (20Hz-20kHz). PM
Maximum output (<1% THD into 47kohm): 8000mV
Maximum power output (<1% THD): 2.67W/25ohm / 7.33W/8ohm
Output Impedance (20Hz-20kHz): 400-500mohm
A-wtd S/N ratio (re. 0dBV): 95.3dB
Distortion (20Hz-20kHz, re. 10mW/0dBV): 0.0005-0.009%/0.0005-0.009%
Frequency resp. (20Hz-20kHz/100kHz): +0.0dB to –0.21dB/–4.2dB
Stereo separation (20Hz-20kHz): 71-102dB
Power consumption: 27W
Dimensions (WHD) / Weight: 440x92x400mm / 13.3kg
Price: £4000