It's sometimes amusing to browse the AudioPorn sites, and the first DAC review on Stereophile currently is of the $5500
AudioNote DAC 2.1x.
This receives high praise from the enthusiastic reviewer. And yet, even as he's dishing out the plaudits he feels the need to qualify his statements: "the sound wasn't buzzy or fuzzy, but it skated right up to the border of same", "The harsh highs were, if anything, a little more grating through the Audio Notes than I heard from CD rips of the album played from my Apple iMac", "the DAC 2.1x Signature, in particular, may generate distortion products", "The question of whether the sound of the Audio Notes should be ... blamed for trading in pleasing distortions will never be answered to the satisfaction of all." But none of this diminishes his ecstatic conclusion: "I have never heard a CD player that beats this combination in the ability to involve me in the magic of notes and rhythms, or that presents lines of notes in such a musical and attention-grabbing manner. Vigorously recommended."
In the measurements section we learn that this device uses an old
Analog Digital AD1865, a chip that's featured in a variety of odd-ball R2R designs (the large OBSOLETE stamp is particularly fetching). But, far more seriously, the designer has chosen to throw his textbook out the window (presuming that he actually owned one) and neglected to filter the output. As is entirely predictable, this wrecks the design, spewing out gobs of aliased image noise which then intermodulates down to the audible spectrum, with a 19kHz tone causing a -52dB spike at 6kHz. Harmonic distortion from low-frequency signals is particularly high, with the 2nd harmonic
alone reaching -50dB. John Atkinson does, at least, have the integrity to declare in summary that, 'it is difficult to avoid the temptation to describe the Audio Note DAC 2.1x Signature as "broken" '. It clearly is.
So it measures like crap, but it 'sounds good'? Where have we heard that before?
Oh yeah ... vinyl.
Just as some people seem to enjoy the compression, noise and distorted frequency response of vinyl, could we be seeing a similar reaction to the nonlinearity of old R2R DACs and distortion produced by 'special' (i.e. wrong) filters? I suspect so. The human mind is incredibly plastic, and we can teach ourselves to enjoy all sorts of strange pleasures. I think the question really is: how far can this go? How long will it be before audiophiles discover the true source of digital audio nirvana and start paying $5k for DACs based on the big daddy of them all, the sublimely musical 14bit TDA 1540? Hold on, it's
happening already: "when I heard the CD104 with just NOS and all capacitor mods - it was so good that I did not believe my ears. It is too good to be true." (yes, that's from Lampizator, makers of the masterpiece
featured earlier in this thread, but they
aren't the only ones).
... Actually, what am I doing wasting time on this thread. Bye guys, I'm off to buy up some ancient CD players so I can rip the chips out and put them in a fancy new box for the next HiFi Show.