Surround-Sound Preamp-Processors

The P5's frequency response, from the unbalanced (RCA) input to the speaker output, measured –0.06dB at 10 Hz, -0.01dB at 20 Hz, -0.15dB at 20 kHz, and -0.58dB at 50 kHz. The frequency response from the balanced (XLR) input to the speaker output measured -0.05 dB at 10Hz, -0.01dB at 20 Hz, -0.16dB at 20kHz, and -0.60dB at 50kHz.

The amplifier's gain measured 28.9dB single-ended and balanced (-6dB setting). The S/N ratio (A-weighted) from 10Hz to 24kHz at 2.83V into 8Ω was -110.6dB single-ended and -111.4dB balanced.

The THD+noise at 2.83V into 8Ω was 0.003% at 20Hz and 1kHz, and 0.002% at 20kHz at the balanced input. Under the same conditions into 4Ω, THD+noise measured 0.003% at 20Hz, 1kHz, and 20kHz, balanced.

Into an 8Ω load, all five channels operating, the P5 clipped (1% THD+noise, to the nearest watt) at 380Wpc at 20Hz and 383Wpc at 1kHz. Into a 4Ω load, all channels driven, it clipped at 612Wpc at 20Hz and 640Wpc at 1kHz.

Into an 8Ω load, with two channels operating, the P5 clipped (1% THD+noise) at 400Wpc at 1kHz. Into a 4Ω load, two channels driven, it clipped at 642Wpc at 1kHz.

The D1's component-video inputs passed a high-definition signal, including resolution test patterns, without obvious degradation.