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Reviewer: Srajan Ebaen
Financial Interests: click here
Source: Esoteric UX-1;Yamamoto YDA-01, MacBook Pro, Hegel CDPA4MkII [on review]
Preamp/Integrated: ModWright DM-36.5; Esoteric C-03, Wyred for Sound STP [on review]
Amp: FirstWatt F5, ModWright KWA-150, Octave MRE-130, Yamamoto A-09S
Speakers: Acoustic System Tango R, Triangle Magellan Cello Sw2 [on review]
Cables: Acoustic System Liveline interconnects, speaker cables and power cords
Stands: 2 x Ikea Molger with Ikea butcher block platforms and Acoustic System footers
Powerline conditioning: 2 x Walker Audio Velocitor S
Sundry accessories: Furutech RD-2 CD demagnetizer; Nanotech Nespa Pro; full-house installation of Acoustic System resonators, noise filters and phase inverters; Advanced Acoustics UK Orbis Wall and Corner
Room size: Sound platform 3 x 4.5m with 2-story slanted ceiling; four steps below continues into 8m long open kitchen, dining room and office which widen to 5.2m with 2.8m ceiling; sound platform space is open to 2nd story landing and 3rd-floor studio; concrete floor, concrete and brick walls, converted barn with no parallel walls nor perfect right angles; short-wall setup with speaker backs facing the 8-meter expanse
Review Component Retail: $5,000

In today's download culture, Esoteric's new SA-50 viewed from its stylishly uncluttered front would seem like another anachronism earmarked for soon extinction. After all, this chunky machine is dedicated to a physical music carrier. Isn't that so declassé, so terribly passé? If you own a collection of 3000 CDs, not (adjust figure to fit your bill). But then, the vast majority of iTunes users actually do view those of us who still own such collections—or worse, carry ambitions to assembling them in the future—as definitely passé. We're a dying breed. Is Esoteric's SA-50 banking on our tired kind?
 

It's on the business end where we upconvert into the 21st century. There are three digital inputs and one of them is the absolutely vital USB. Hurray. This calls for an immediate rewrite of the intro. The SA-50 is actually a 32-bit digital-to-analog multi input converter. It simply adds an ultra-quality purpose-designed SACD/CD transport as bonus. But its defeatable remote-controlled attenuator really makes it a digital 4-source preamplifier with paralleled analog outputs on RCA and XLR. But wait, the latter are defeatable. Turned off, the SA-50 turns into a transport that outputs digital data on RCA or Toslink. But wait, you can even turn off the digital outputs. Is this machine the ultimate multi tasker then? Whatever you call it, it's not just another tired CD player for diehard dinosaurs.


In stopped or playback mode, a 2-sec press on the front panel mode button calls up the software menu. This can cycle through nine items. The items are CD/Din>, SACD>, DF>, Word>, 2ndPLL>, D-Out>, Att>, Out> and USB-PW>. Each item offers selectable adjustments which get chosen with the prev/next track controls on the front panel or remote. For CD/Din>, we have ORG (original) which means, no upconversion. In transport mode (using an external DAC), this runs the internal 32-bit 8-times oversampling digital filter without any 'enhancements'. 2Fs invokes upconversion x 2, 4Fs x 4, i.e. to 88.2 and 176.4kHz respectively. DSD upconverts a PCM audio signal to Direct Stream Digital.

For SACD playback, the signal processing options are DSD for no conversion and native playback; 2FS+6 for 88.2kHz/32-bit PCM conversion with a 6dB gain boost to standardize the output with regular CD; 4FS+6 for an equivalent 176.4kHz scheme; and 2Fs and 4Fs without the gain boost.


DF> refers to digital filter* and is applicable only for PCM audio, i.e. CD not upconverted to DSD or SACD converted to PCM. The FIR filter is a 32-bit Finite Impulse Response affair that applies x 8 oversampling. S_DLY is a 32-bit short-delay 8 x oversampling filter which "provides an impulse response without pre-echo, natural attack and reverberation."

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* Any discussion on digital filters will have to include frequency and impulse response and the associated terms pre- and post ringing. The latter are to be understood as unnatural echoes which bracket the recorded signal before and after. The early brick-wall filters (called sharp or steep for their high-order nature) added ca. 20 cycles of pre- and post ringing to badly smear all musical transients and decays. Particularly unnatural was the pre-ringing preceding the 'causal' event in time. Later shallower or slower roll-off filters improved the transient response by limiting the echoes on either side of the impulse to one cycle. The trade off was HF leakage of aliasing artifacts of the digital conversion process which the steeper filters removed successfully. Those who implemented such softer filters proposed that the broad-band benefits (less time smear by a factor of 20) outshone the liabilities in the treble where the aliasing images showed up again.

Advocates of eliminating the digital filter altogether proposed later that the perfect transient response of their solution overrode the broad-scale high-level aliasing distortion that now invaded the playback signal; and the audible treble roll-off associated with this scheme. By 2004, an AES paper had proposed a so-called apodizing filter which rearranged the earlier trade-offs by eliminated pre-ringing altogether (arguably the most unnatural digital artifact) but shifting that energy into the musically more benign post ringing (where its lower amplitude compared to the originating event would get masked) and introducing some phase error in the higher frequencies. Apodizing filters presently rely on custom DSP code not implemented on stock converter chips. Meridian's Bob Stuart has been a forerunner of customized 'non-standard' digital filters and Ayre Acoustics recently joined the movement with a simplified white paper that explains their latest filter implementation. Stereophile's John Atkinson has some fine measurements and comments on Meridian's asymmetrical apodizing filter here, calling its behavior "intriguing".


PS Audio's new PerfectWave DAC offers its owners a choice of digital filters including a linear phase soft knee filter, minimum phase soft knee filter, linear phase brickwall filter, minimum phase apodizing filter and linear phase apodizing filter. Cynics could conclude over-featurization to clinch a sale. Cooler heads meanwhile should assume that there's no consensus yet on which scheme of compromises is sonically superior. Hence PS Audio lets the customer decide, perhaps even on a CD to CD, file to file or source to source basis.


Back with our review subject, the description for its S-DLY digital filter option very much reads like an apodizing solution. When I queried Kazutaka Tsuda at Esoteric Japan, he at first didn't understand the reference. When I forwarded a link to Ayre's web paper, he simply stated "it looks similar". The WORD> option obviously refers to an external master clock. Permitted clock frequencies are 44.1/88.2/176.4/100kHz. 2ndPLL> sets the master clock extraction method for each of the three digital inputs.
In 'on' mode, a second phase-locked loop circuit with an internal voltage-controlled crystal oscillator improves jitter performance. This feature does not work with 32-bit input signal.


D-OUT> allows defeating the digital output, ATT> can activate the internal volume control. OUT> controls the analog outputs. They can all be turned off or off, turned on individually and the XLR output can be shifted from pin 2 to 3. The final USB_PW> item decides whether the USB input remains active regardless of which input is selected. In 'on' mode, the SA-50 continues to see your PC. This avoids having to restart the audio player software on a PC for the next USB audio session but should be deactivated for best CD playback.

After this brief descent into the menu options (there's even a factory reset), it's obvious how the SA-50 is rather more than just another statement CD player for the fossils amongst us. It's a digital preamplifier wit true 32-bit processing and USB PC interface. The famous VOSP sled for superior data extraction from CD and SACD is simply integral and as such, an extra bonus. (Dinosaurs will consider the USB feature extra of course, perhaps even unnecessary. More enlightened users should call the whole player surprisingly comprehensive, period.) Built to typical Esoteric vault standards, the unit weighs nearly 40 lbs. It sports every remote convenience in the good book and is full-featured, ergonomically friendly and luxurious of construction and countenance. For Esoteric, it's also priced as a midfielder. For anyone who has pleaded for digital inputs on expensive players, the SA-50 from one of the leaders in the sector crosses off a lot of check boxes. The hi-rez brigade will still cry wolf because this USB port doesn't transcend 16/44 input data and Blutooth fanatics who must have wireless everything aren't catered to. As aren't Firewirers.


Those not on the SACD bandwagon can take refuge in a transport built for that format's far higher rotational speeds. Such spinners are by definition overbuilt for the more leisurely 200 to 500 RPM speeds of CD. While you may not take advantage of DSD software, you're definitely benefiting from more robust hardware. On that 'hard' in ware, the remote is a chunky metal wand, the integral three footers customized metal decouplers. In toto, physical and other in-specs-ions find the SA-50 to be an impressive package of features and functions. One applauds in particular the inclusion of USB whose processing between input and output undergoes exactly the same user-selectable math as standard Redbook. This builds not only bridges. It also affords the reviewer and future owner opportunities to compare delivery formats (optical vs. magnetic) with identical post-processing options. (Click here for an 886KB PDF on Esoteric transports, here for the full owner's manual of the SA-50.)

Put differently, the SA-50 could be that last player you'd ever need if your main focus remained on CD (and/or SACD) but you felt in lock step with a future of downloads and streaming. That future won't eradicate CD availability for many years. Nor will it invalidate any of the discs you already own (at least until those refuse to play). Where the SA-50 continues to look backwards is in its embrace of an overbuilt transport. Habitual rippers import their music files from CD to hard disk via far cheaper PC drives. They rely on free software to check for extraction errors and automate necessary re-reads. This seems to negate the need for expensive sleds. On the other side of that equation sit CD-centric playback solutions dubbed memory players. They use large RAM buffers to perfect the read-in process over cheap drives. PS Audio's PerfectWave duo for example is deeper into that future than the one-box Esoteric. Which should have your priorities better covered is your question to answer.