High Fidelity Review SACD News Story: Audio Aero To ‘Improve’ DSD by Converting it to PCM. Audio Aero’s high-end SACD player takes the unusual step of deliberately converting DSD to PCM in order to improve the standard of playback. The Prestige A/V player, available in late 2002, is a combination DVD-Video and SACD machine which implements Audio Aero’s S.T.A.R.S.® process, a proprietary 32/192 re-sampling technology. It is used to enhance the playback of DVD-Video, CD, CD-R and CD-RW, and can also be applied to signals routed via the player’s own digital inputs (front left and right channels only). Uniquely, for SACD playback, the Prestige A/V player uses 24bit 192kHz PCM digital to analogue conversion with what Audio Aero describe as a “DSD/PCM bridge”. Intrigued by this, I asked Jean-Paul Combelles, technical and commercial manager for Audio Aero just what is meant by “DSD/PCM bridge”? “The DSD to PCM bridge is a DSD to PCM converter that affords a 9dB improvement to the SACD signal-to-noise ratio by reducing the high frequency noise present due to the 2.82MHz sampling frequency. This will also allow enhanced functionality from the analogue stages,” explained Jean-Paul. This statement actually confirms what many DSD sceptics have been citing as a negative aspect of SACD for some time, so I wanted to clarify just what Jean-Paul meant. I asked him to confirm that all DSD (SACD) sources are converted to PCM in the player, where a filter removes some of the ultrasonic noise present and thereby improves the signal-to-noise ratio by 9dB. I also asked that if this really were the case, whether he thought that SACD proponents would object to DSD being converted to PCM prior to D/A conversion? A pure DSD signal path appears to be the panacea of many SACD listeners. Jean-Paul reiterated his earlier response: “…suppressing the ultrasonic noise will allow better functioning of the following stages (DAC and analogue stage). By reducing this noise, the residual signal we create will be boosted by 9dB using our enhancement techniques.” Unfortunately any more technical detail is considered confidential.