Philips CD960 CD player Lab Report

Lab Report

Comparisons with Philips' 4x oversampled 14-bit players, the CD100 [HFN Oct '11], CD104 [HFN Apr '14] and CD303 [HFN Nov '13] are of academic interest, but the CD960's family tree really begins with Philip's CD450 [HFN Aug '14] launched a couple of years earlier. Both players use the classic SAA7220 4x oversampling filter and two-channel TDA1541 16-bit DAC, but the CD960 uses a superior CDM-1 transport and 'A' version of the DAC. The digital filter – a moderate roll-off linear phase type – offers a modest 41dB rejection of stopband images but a much reduced passband response ripple, down from ±0.25dB in those earlier players to just ±0.03dB here [see Graph 2, below]. By modern standards this is still a high figure, but in 1987 was state-of-the-art for 4x oversampling at a 16-bit wordlength!

However, the CD960's analogue stage and TDA1541A DAC brings a real uplift in performance over the CD450. The maximum output level is not dissimilar at 2.3V but the output impedance is lower at 54-59ohm and the S/N ratio improved by 2dB to 110dB in the CD960. Few modern players will match this! Distortion is lower too, and jitter suppression excellent at 160psec, although the THD versus digital level trends [see Graph 1, below] clearly illustrate that the SAA7220/TDA1541 chipset still lacks the uniformity of modern DAC solutions, as does its –2dB offset in linearity at just –90dBFs. More positively, from a subjective standpoint, distortion is not only low at 0.0004% at 0dBFs, rising to 0.0024%/–10dBFs and 0.021%/–30dBFs, but this trend is well matched at low, mid and high frequencies. So the CD960's 'colour' is very uniform across the audible spectrum, and beyond. Finally, ultrasonic noise is low (lower than the PDM/PWM DACs that were to emerge from 1989 onwards). PM


Distortion versus 16-bit CD digital signal level over a 120dB range (black = 1kHz; cyan = 20kHz)


Frequency (magnitude) and impulse (time)responses. Note ±0.03dB response ripple

Maximum output level / Impedance 2.29Vrms / 54-59ohm
A-wtd S/N ratio 109.9dB
Distortion (1kHz, 0dBFs/–30dBFs) 0.00039% / 0.021%
Distortion & Noise (20kHz, 0dBFs/–30dBFs) 0.00065% / 0.030%
Frequency response (20Hz-20kHz) +0.0 to –0.17dB
Digital jitter 160psec
Resolution @ –90dB/–100dB –2.0dB / –2.1dB
Power consumption 13W
Dimensions (WHD) / Weight 420x100x378mm / 10kg