A DAC that offer non oversampling (NOS) output options alongside conventionally filtered ones is a rarity, making the AMR CD-777 – which is both CD player and outboard DAC – an unusual beast indeed. In fact it offers two NOS options, called Direct Mastering I and Direct Mastering II, two oversampling modes, 2x and 4x, and two upsampling modes, to 96kHz or 192kHz.
The CD-777’s top plate incorporates the CD mechanism under a sliding panel; a small magnetic puck holds the disc firmly. To either side are ventilation slots. The fascia has a central dot-matrix display panel and five circular push buttons. The left one powers the unit up or down to/from standby, the display showing a countdown after power-up as the circuit stabilises. The remaining four offer the usual CD player controls.
The supplied remote handset is the only means of addressing functions such as switching between CD player and DAC modes and the selection of reconstruction filter. It is unusual in offering some controls via its touch-panel and others via buttons beneath.
There are a number of obvious questions to ask of a product like the CD-777, the most obvious of which is: how do the different output modes compare? AMR suggests that Direct Mastering II should be regarded as the default setting, and it was indeed that little bit clearer and crisper sounding – although, as AMR points out, Direct Mastering I may be preferred with bright source material.
THE BEST MODE
In our principally Naim test system, Direct Mastering II mode did indeed reign supreme. It was simply more open-sounding and ballsy. This was particularly apparent when playing the scherzo from Mahler’s Symphony 6 on LSO Live [LSO0038], a Tony Faulkner recording prepared for CD release from higher sampling-rate masters using Tony’s adjacent sample averaging technique, which applies much gentler filtering than is used in conventional downsampling. Unsurprisingly, this track relished Direct Mastering II mode, the CD- 777’s oversampled and upsampled options seeming somewhat closedin and mechanical by comparison.
Actually we were listening to a rip of the track played via USB connection from a Mac mini running Windows XP and J River Media Center v15. Which brings us to the second obvious question: how does the CD-777 fare as a CD player compared to the CD-777 in DAC mode? We compared a number of discs and rips, but listening impressions (using the USB interface in DAC mode) were broadly similar. AMR claims that its USB input delivers ‘computer-based audio at the level of direct CD playback’ but we think that that sells it short since we consistently preferred the sound of the rip to that of the disc. Eva Cassidy’s acoustic guitar [Simply Eva, Blix Street Records] was cleaner and her voice swooped and soared more freely. It’s not that the CD-777 is a let-down in CD mode rather that meticulously realised computer replay can deliver even better results.
Then which is the better of the CD-777’s digital interfaces – USB or S/PDIF? We had a distinct preference for the coaxial option, eg, with Brian Ferneyhough’s Incipits [ripped from Kairos 0013072KAI] where obbligato percussion and sawing solo viola had sharper focus and snappier dynamics, and there was a better sense of the acoustic.
There’s something about the sound of NOS DACs that, in the right system, breathes new life into CD replay. The AMR CD-777 allows you to judge this issue for yourself, and even choose different filtering according to source material. It’s a fine CD player and even better sounding DAC.
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