How direct is direct?
Minor nit alert: Folks used to up
counting displays where higher numbers imply more loudness must pay attention. Unlike my C-03 preamp which allows subtractive or additive mode, the SA-50 is preset for subtractive. Engineering could prevent possible mishaps by reversing this. Intuitively, more suggests more, not less. Higher numbers should equal louder, zero no sound at all. But here it's reversed. -40dB is quieter than -10dB by far. Get a customer confused on this count and his zero will blow out her ear drums. And possibly his tweeters too.
The first comparison involved the C-03 set to zero gain to stack the cards in the player's favor. If such was even possible. Audiophiles who have extensively experimented with direct drive vs. active preamps know that nearly invariably, direct drive suffers bleached colors and dynamics by comparison. Exceptions like the Audio Aero or Ancient Audio machines—my Polish Lektor Prime runs a 6H30-based fully balanced output stage with a max output of 7V and adds an analog input to really be a CDP/miniature preamp in one enclosure—are quite rare. Esoteric's C-03 preamp even in "passive" no-gain mode still runs the signal between +/-38V rails to propose rather different drive
potential than one would expect from a CD player's output stage. Contrary to popular lore which equates max resolution with a minimum of complexity, the higher control an active preamp exerts over the input stage of an amplifier can actually increase
detail perception and thus, subjective resolution. Would the SA-50 be an exception to such generalized but oft confirmed observations?
Not really. In the showdown against the 0-gain C-03, it was admittedly a lot closer than anticipated even though the 'indirect' route hung just a bit more body on the performers. But once the C-03 was set to 12dB of gain (never mind 24dB), the game was over on the Triangle speakers which excel at speed and resolution yet demand an infusion of physicality from the preceding electronics.
The advantages of a—cough—$10,000 additional preamp were undeniable. On something voiced far meatier and buxom like my Zu Essence speakers however which do not ask for the caloric expander action of preamp gain, the direct route off the SA-50 isn't mere temporary convenience feature to make sound while you save up for a preamp. In such a context, it could well become the final solution. Additional consideration will be speaker sensitivity so as to not listen too deep in digital attenuation mode*. The ultimate not usefulness (it is very
useful) but performance legitimacy of the digital 32-bit attenuator thus depends on system context, particularly the degree of fleshiness which the components must provide to accommodate whatever the speakers bring to the table. If the final sound is too lean and 'electrostatish', you'll want a dedicated active preamplifier. The STP from Wyred4Sound's EJ Sarmento is a brilliant within-reach option and virtual stand-in for the C-03 if you don't need or want the latter's adaptive gain feature (which for a reviewer's endless conga line of arriving and departing amps is truly the cat's meow).
*Another possible use for the attenuator is to trim the input signal for an existing high-gain preamplifier
that heretofore offered volume steps too coarse between too quiet and too loud.
How smart is digital math?
The various upsampling and filter option combinations are super brainy but like higher math, more or less elusive to mere mortals and their real-world systems. Some are more audible than other. In my system and to these ears for example, 2 x and 4 x upsampling were more obvious in their consecutive increase of ambient presence or recorded space than the minor shift in transient sharpness which toggling between the FIR and apodizing filter invoked. The latter softened the edges somewhat to suggest that some 'digital sharpness' is due to pre-ringing. That's been the battle cry of the zero-sampling brigade all along but their solution incurs a soft treble for one which Esoteric's S-DLY filter does not. As stated earlier, my preferred setup for RedBook was upsampling to 176.4kHz with the apodizing filter, not CD upsampled to DSD. Superior direct-to-DSD tracks—not converted PCM masters—as on Todd Garfinkle's MA on SA
make a compelling statement for the SACD format. Yet its gaping absence in local record shops where you can listen to partial tracks over an MP3 master data base or entire CDs over a headphone-equipped CD player in a trial nook make it a non event in my own music consumer life. There are no SACDs to try out or chance upon and I'm still one of those sad antiques who prefers to give his business to local flesh 'n' blood merchants in cash rather than remote websites by credit card. Hence as far as I'm concerned, SACD never happened.
Adding it all up
Feature wise, the 4-in-one SA-50 is unusually endowed. That the comprehensive upsampling/filter choices are available on the fly—the music merely drops out for one second while the circuitry switches—is particularly brilliant. Ultra purist meanwhile are the various on/off settings that can defeat or activate specific outputs, inputs and features to remove them from the signal path when not needed or desired. The amp-direct 32-bit digital attenuator mode meanwhile can be a big money saver for the right customer who happily goes preamp-less by not needing analog inputs and who owns the appropriate amp/speaker combination. The biggest deal with the SA-50 however must be its USB implementation. It offers complete and utter equality of signal processing and
sound between hard-disk and 'soft' disc modes.
By not challenging Apple for supremacy over the most widely embraced, most intuitive GUI of streaming music
to instead enter the picture strategically where code-writing expertise expires—premium sonics right at the USB interface—Esoteric leverages its core expertise rather than cobbling together a complete music server. As we have seen with Meridian, Naim and Linn, that nearly by design would have to be a lot more expensive than existing Mac or Windows-based computer solutions that can be had for around $1,000 inclusive of all necessary software and storage capacity.
What it means is that a nearly state-of-the-art, nearly do-everything digital front can now be assembled around the $5,000 Esoteric SA-50 by simply adding the smallest MacBook (or Windows equivalent) and a quality USB cable. Limitations remain for downloadable hi-rez files (USB here is restricted to 16/44) and this particular system couldn't do DVD-A (very possibly a non-issue for most).
The smart presence of digital outputs meanwhile guarantees an upgrade path to full SOTA status with your outboard converter of choice should you own or know of one whose analog output stage significantly beats Esoteric's. Add corporate wherewithal to hopefully weather the current economic challenges which could put out of business many a smaller operator; Esoteric's first-rate consumer support on open record by many satisfied users; build quality which in this sector has become the envy of most; and a price which, considering the name decal, is actually on the lower side... and what's bloody not to love? That's neither a trick question nor writerly avoidance for having to make a definitive statement. Based on my personal exposure level in general and Esoteric's in particular, I think this machine is very
loaded on the value side of that price/performance scale and definitely
the most desirable one-box machine in Esoteric's stable at the moment.