Vintage

With the digital EQ and Sound Field Processor defeated, the CX-10000 reverts to its analogue in/out mode offering a maximum 20dB gain and 93dB A-wtd S/N ratio (re. 0dBV). The HF response is very extended, reaching out to –0.1dB/20kHz and –1.7dB/100kHz, although the infra-bass rolls away from –0.5dB/ 20Hz to –30dB/5Hz. Analogue distortion is very low at just 0.0005%/1kHz before falling to 0.0003%/20kHz (all re. 0dBV), while the maximum 5V single-ended output is offered from a moderate 523-555ohm source impedance and with an across-the-board (20Hz-20kHz) stereo separation of >80dB.

The digital stage brings about an inversion of the output’s absolute phase, the response limited by the maximum 44.1kHz and 48kHz sample rates, while its roll-off, ripple and ‘time distortions’ are determined by the YM3619 4x oversampling filter. This is a high-tap, 225th-order linear-phase filter that offers a significant 98dB stopband rejection, contrasting with Philips’ contemporary SAA7220 4x filter which possessed ‘gentler’ coefficients and a limited 41dB stopband rejection. In-band ripple is limited to ±0.01dB and the response is flat to –0.15dB/20kHz albeit with the low-bass roll-off already seen in the preamp stage. Clock accuracy is within Class 1 standard at +45ppm but jitter from the YM3615 sample-and-hold and 18-bit YM3023 DAC is higher than the 16-bit baseline of 116psec at 850psec, and almost entirely data-induced [Graph 2]. Tested at a 2V output, the A-wtd S/N ratio is a steady 105.7dB but there’s a drift in low-level linearity of ~0.5-bit below –90dBFs, resulting in an overall resolution no greater than 16 bits. Below –20dBFs, distortion is mercifully consistent with frequency [see Graph 1], falling to a minimum of 0.0009-0.0018% (re. 20Hz-20kHz). PM