Naim CDX2/DAC - Endnu en god anmeldelse - 1/4 Hi-Fi News har haft Naim CDX2 og DAC på besøg. Denne kombination skabte begejstring hos Keith Howard. Læs testen her: Naim CDX2/DAC It's been a long time coming, but Naim has finally unveiled its first standalone DAC, able to improve the performance of its CDX2 and promising zero jitter, to boot From almost anybody else, the launch of a new outboard DAC would rate as one of the audio industry's more mundane events. But a DAC from Naim Audio - called, yes, the Naim DAC - is a development of more moment. Not so much for what it is but because it unravels what was, until now, one of the marque's design dogmas. Naim was late to the digital audio party, launching its first CD player in 1991, almost a decade after Compact Disc's arrival. Even then, it idiosyncratically refused to equip its silver disc spinners with digital outputs, on the basis that a one-box solution - disc mechanism and digital-to-analogue converter circuitry combined - will always give better sound than a two-box one, where the disc reading and conversion functions are physically separated. Naim had a point in that difficulties do indeed arise with recovering the master clock from ,embedded clock' interfaces like S/PDIF and AES/EBU. But while Naim declared the problem insuperable, others in the audio industry knuckled down and, by various means, overcame it. THE SALISBURY SOLUTION Only now has Naim felt it appropriate to follow suit but that's not to say that the Naim DAC is by any means a me-too product - it     manifestly is not. Naim has developed its own solution to the S/PDIF jitter issue, comprising a buffer memory and switchable fixed-frequency master oscillators which are alternated in order to match, on average, the input data rate. It has also deployed optical data couplers within to provide ground isolation, opted for 40-bit floating point processing rather than the more usual 32-bit to ensure sufficient accuracy with 24-bit source material, and chosen to use an IIR rather than FIR digital filter because the reduced computational load was found to benefit the sound, even when the filters' amplitude and phase responses were identical. Of course, Naim's digital source components have had to be upgraded to incorporate S/PDIF output. Here too an unusual approach is taken in that the S/PDIF circuitry is disabled when the player's own analogue output stages are enabled. This doesn't just mean that the digital outputs are switched off: power is removed from the S/PDIF modulator to prevent it radiating radio frequency interference. AES/EBU balanced digital >> Næste side       Nørregade 19-21   9000 Aalborg   Tlf.: +45 9816 1410   E-mail: mail