Continuing The Baseball Analogy With The Esoteric D-07 DAC
Readers familiar with baseball know that it's a game called by umpires. Umpires use their eyes and ears to make judgement calls during every game. Even though the strike zone is clearly defined in the baseball rulebook there are disagreements during every game about balls and strikes. Reviewing audio components is somewhat similar. Writers user their eyes and ears to make judgements during every component evaluation period. Some judgments are based on objective criteria such as jitter specs. Even so there are many disagreements how to measure and interpret these specs or results. Other judgements such as sound quality are subjective and never fail to bring about disagreements after every review. What this boils down to is a series of judgments and opinions. Calling it as one sees it. One umpire's strike three is another umpire's ball four. One audio writer's "terrible USB implementation" is inside another writer's "best USB DAC on the market." Fortunately in high-end audio consumers have an opportunity to make these judgement calls themselves and to use instant replay until a satisfactory opinion can be rendered.
Computer Audiophile readers are encouraged to check out Vade Forrester's recent review over at SoundStage for a contrasting opinion of the D-07. [Link]
Strike One (Not a good start)
When the Esoteric D-07 DAC arrived I connected it to my system and open the manual for a cursory page flip or two. I usually get components up and running and return to the manual afterward for clarification and recommendations. Sure it's backward but I believe I'm in a group with a majority of people when it comes to manual reading. I skipped to the USB and computer audio portions of the manual first. To my dismay the D-07 manual instructs readers to improperly configure the operating system, to use Windows Media Player, and says, "The USB-connected personal computer must be running with Microsoft Windows XP or Windows Vista. Other operating systems are not guaranteed." In addition the manual contains incorrect and misleading information about the D-07 USB input.
A. Information about using Windows
The statement that Windows is the only operating system guaranteed to to work with the D-07 is troubling. If Windows truly was the only OS guaranteed to work I could simply make a note of this deficiency. However, there is nothing special about the D-07 that even remotely suggests it should not work with other operating systems. The D-07 USB implementation works with an operating system's built-in USB drivers. In fact I've yet to see a USB DAC using native device drivers that doesn't work on at lest Windows and Mac OS X. I'm unsure what lead to this statement's placement in the manual, but it's not helping Esoteric win over potential customers using Mac OS X.
I consider any computer configuration that does not output bit perfect audio to be an incorrect configuration. Readers can imagine the look on my face when I read the following information in the D-07 manual.
- "Use the OS based media player for playback (Windows Media Player, etc)."
- "If the sound does not playback normally when you are using a supported operating system, and the connections are correct as described above, check the following points. Click “Control Panel” and then “Sound”. Click the “Playback” tab and check that “SPDIF Interface ESOTERIC D-07” is selected. [The] Following settings are also recommended: Clicking “Properties” at this window (“Control Panel” and then “Sound”) displays the following window (pictured here pdf). Click “Supported Formats”, then uncheck the check box of “Encoded Formats”. Check the check box of the sample rate you want to set. Click “Advanced”. Select “2 channel, 24 bit, ********Hz”. Regardless of the format of your selected music file, PCM signals are sent at the selected sampling rate when using the USB connection."
Recommending Windows Media Player without discussing the negative sonic impact of imperfect output is a mistake. Following this the manual goes on to show readers how setup the Sound options within the Windows Control Panel. All the provided information is technically correct, but is absolutely the incorrect way to output bit transparent audio. There is nothing written about Exclusive Mode, or WASAPI, Kernel Streaming, and ASIO output methods. In the J River Media Center article I wrote on 02/24/2010 [Link] I actually recommend setting the sample rate in the Windows Control Panel to a rate that is unlikely to every be used. This way a DAC that displays the incoming sample rate will let the listener know something is configured incorrectly if this unlikely sample rate is displayed. Playback applications should never rely on the Windows Audio Control Panel settings if bit transparent audio is desired. These applications should use WASAPI, Kernel Streaming or ASIO for bit transparent output, even at the 16-bit, 44.1 kHz sample rate.
Manufacturers should either instruct customers correctly or not instruct them at all. Esoteric is an industry leader in digital audio and a company others look to for innovation. Esoteric's explanation of how to output audio is likely viewed by distributors, dealers, and customers around the world as the correct way to use a computer for high-end audio. This is a disservice to the aforementioned entities and the industry as a whole. All of this information in the manual about Windows only and how to configure Windows appears to be an oversight by Esoteric at best and lack of research or interest in computer playback at worst.
B. Incorrect or misleading information about the USB input
Many potential customers and Computer Audiophile readers frequently rely on user manuals provided by manufacturers to find correct information about components. Questions arise about sample rate support via USB input or specifics about upsampling all the time. Quite often a reader will paste information from the user manual into a comment and the thread will conclude with the assumed correct information straight from the horses mouth. With this in mind, here are a few specs copied word for word from the Esoteric D-07 DAC user manual (bold emphasis mine).
- "Input sampling frequencies XLR*, RCA, OPTICAL 32, 44.1, 48, 88.2, 96, 176.4, 192 (kHz) USB 32, 44.1, 48, 88.2, 96 (kHz) * Only the XLR terminal can receive DSD signals when connecting with an Esoteric P-05 CD/SACD transport. (The Esoteric P-05 is an optional component not included with this device)."
- "The D-07 features a variety of digital inputs, including a USB terminal, that support the playback of Super Audio CDs together with ESOTERIC’s Super Audio CD Transport products, as well as the playback of high-resolution music files. The D-07’s USB input can accept native resolution up to 24bit/96kHz."
- [Analog output] Output terminals XLR (2ch) x1 RCA (2ch) x1 Output impedance XLR: 100? RCA: 100? Maximum output level 2.2Vrms (1 kHz, full scale, 10k?) Frequency response 5 Hz - 40 kHz S/N ratio 130 dB Total harmonic distortion 0.001 % (1 kHz) [Digital input] Balanced digital input XLR x1 24bit/192kHz Coaxial digital input RCA x2 24bit/192kHz Optical digital input Optical x1 24bit/192kHz USB input USB Type B x 1 24bit/96kHz [Word Sync output] Output terminal BNC x 1 Output frequency 44.1, 88.2, 176.4, 48, 96, 192 kHz (rectangular wave) Output level TTL level (75 ?) [Word Sync input] Input terminal BNC x 1 Input frequency 44.1, 88.2, 176.4, 48, 96, 192, 100 kHz (rectangular wave) Input impedance 75 ? Input level TTL level [General] Power supply AC 230V 50Hz AC 120V 60Hz AC 220V 60Hz Power consumption 7 Watt External dimensions(WxHxD) 442 mm x 103.5 mm x 346 mm (17-3/8" x 4-1/16" x 13-5/8") Weight 9.5 kg (21 lbs)
The first example is simply incorrect. The Esoteric D-07 cannot handle 88.2 kHz audio. Period. Either it does not play or the playback application is required to down or upsample the audio in order for the D-07 to handle it via USB. The second example clearly leads average unlearned computer audiophiles to believe the 88.2 kHz sampling frequency is supported. Resolutions up to 24/96 has an inherent assumption associated with the phrase that all usable sample rates or all sample rates supported by the other interfaces up to 24/96 are supported. The third example is simply a reiteration through implication that support for 24/96 includes the relevant sample rates below. The above examples are not simply nitpicking. These are real world examples from the D-07 manual that will mislead and disappoint consumers.
Ball One (Pretty good)
The Esoteric D-07 is certainly a jack of all trades. Its XLR, RCA, and optical inputs all support 32, 44.1, 48, 88.2, 96, 176.4, 192 (kHz) and the USB input supports 32, 44.1, 48, 96 (kHz). The D-07's 32-bit digital volume control allows one to bypass a preamplifier and the associated interconnects. Support for DSD audio from SACDs is enabled via the XLR input when using the Esoteric P-05 transport. Fans of upsampling will approve of the D-07's support for 2x, 4x, and DSD upsampling options. The D-07 offers two digital filter choices that only apply to PCM audio signals not upsampled to DSD. The Finite Impulse Response filter is a 32-bit filter that oversamples the input signal to eight times the frequency of the original. According to Esoteric this is supposed to provide a "fuller, richer and deeper sound" but I found it to be a bit over-exaggerated, inaccurate, and almost cartoonish sounding in my system. I used the S_DLY Apodizing filter for nearly all of the review period. The D-07 manual describes this filter as, "A 32-bit short delay filter oversamples the input signal to 8 times the frequency of the original signal. This provides an impulse response without pre-echo, natural attack and reverberation. This setting provides tonal quality that is closer to the original recorded material and without enhancement." I don't disagree with this statement. I think the Apodizing filter is closer to the above attributes than the FIR filter. Unfortunately just because the filter is closer to something doesn't mean it is close to something. During the review I also used a Lynx AES16 audio card that's capable of accepting incoming word clock signals while sending out AES digital audio. In the past I've achieved very good sound using a DAC to send word clock out to a Lynx AES16 card. Using the Lynx AES16 / Esoteric D-07 combination did offer sound quality superior to the USB input and equivalent to using the Weiss INT202 FireWire to AES / S/PDIF converter into the D-07. The D-07 can also receive an incoming word clock signal from an external clock such as the Esoteric G-03X or G-0Rb, or a Lynx AES16 card.
Strike Two - Foul Ball
When Esoteric announced the immanent release of a DAC with USB input many computer audiophiles, including myself, were pleased to see such an esteemed company get into the game. I certainly applaud Esoteric for thinking about computer audio and the next phase of high-end audio reproduction. However, it now appears that computer based audio and the USB input were afterthoughts to Esoteric. Below is information obtained from the USBProber application. It clearly shows there is no support for 88200 Hz and the USB implementation as an Isochronous adaptive data endpoint. Surely I never discount any USB interface because it is adaptive as opposed to asynchronous, but this is simply an additional data point to consider when evaluating a product. As it turns out the D-07 sound quality via USB input was my least favorite. In this case the specifications (adaptive USB) and my listening experience (not positive) both jibe.
- Audio Class Specific Audio Data Format
Audio Stream Format Type Desc.
Format Type: 1 PCM
Number Of Channels: 2 STEREO
Sub Frame Size: 2
Bit Resolution: 16
Sample Frequency Type: 0x04 (Discrete)
Sample Frequency: 32000 Hz
Sample Frequency: 44100 Hz
Sample Frequency: 48000 Hz
Sample Frequency: 96000 Hz
Endpoint 0x03 - Isochronous Output
Address: 0x03 (OUT)
Attributes: 0x09 (Isochronous adaptive data endpoint)
Max Packet Size: 388
Polling Interval: 1 ms
Strike Three (There's always next time)
Most disappointing to me was the sound quality of the Esoteric D-07. I could easy look beyond the previously mentioned strikes against the DAC if the sound quality was spectacular. Unfortunately I was underwhelmed by nearly everything I heard coming from the D-07. One important item to keep in mind while reading my sound quality assessment is the rest of the audio components used throughout the review. I only evaluated the D-07 using my current playback system. This is comprised of the D-07 feeding a McIntosh MC275 tube amplifier directly via Kimber Select RCA interconnects, and the MC275 feeding Verity Audio Fidelio loudspeakers via Kimber speaker cable. Feeding the DAC was both Windows and Mac OS X based music servers using a Weiss INT202 FireWire to AES-S/PDIF converter, straight USB, or an AES digital signal from a Lynx AES16 card. I am willing to say this may not have provided the best synergy for the D-07. Yet another reason I encourage readers to check out Vade Forrester's D-07 review mentioned earlier in this article.
The first thing that comes to mind when describing the sound quality of the D-07 is a photographic print. The sound of the D-07 has a matte character to it as opposed to a glossy character. Ideally there would be no character to the sound of this DAC, but in the real world a more acceptable character would lie somewhere in between matte and glossy. Throughout the review I used a verity of music to evaluate the D-07. In heavy rotation was my standard Shelby Lynne album Tiers, Lies, and Alibis, Petteri Iivonen's Art of the Violin at 24/88.2 ( Yarlung Records 05787), Jack Johnson's compete catalog, Nat King Cole's The Very Thought of You (Analogue Productions CAPP 1084 SA), and Britten's Orchestra by Michael Stern's Kansas City Symphony at 24/176.4 (Reference Recordings HR-120 HRx). No matter what music I played I could not shake the matte sound. I felt like there was a thin sheet hanging between my speakers and listening chair that removed detail throughout the frequency spectrum. The Esoteric D-07 did not allow me to hear into the music at all. I frequently had to turn up the volume to loud levels in order to hear fine details in a recording like Britten's Orchestra. The D-07's USB input was clearly inferior to the others including optical S/PDIF. Using the Weiss INT202 improved the sound quality compared to USB whether I entered the DAC via AES or coaxial S/PDIF. I heard no difference between AES and coaxial S/PDIF using the Weiss / Esoteric combination.
Toward the end of the review period I tried very hard to narrow down the cause of my displeasure with the D-07. The sound was simply dead and I really wanted to make it come alive, to experience what so many satisfied Esoteric customers experience daily. I first looked into the D-07's upsampling capability. As many Computer Audiophile readers know I am not a fan of manual upsampling. I call it manual because it's an option DAC users can manually enable, disable, or adjust. I consider upsampling hard coded by a manufacturer to be automatic or uncontrollable by the user. The D-07 allows users to enable, disable or adjust this upsampling feature. In my opinion the sound quality was inversely proportional to the amount of upsampling done by the DAC. The higher I upsampled the more reverb I lost and the less I liked the sound. After upsampling I spent more time with the D-07's Finite Impulse Response and S_DLY Apodizing digital filters. The inaccuracy of the FIR filter was clearly inferior to the Apodizing filter. As I said earlier the Apodizing filter was better than the FIR filter, but it didn't help or hurt the sound enough for me to conclude how much of the sound quality was due to filtering. I think it's fair to say that I simply don't know why the D-07 was such a disappointment in my system. My guess is a little bit of everything, Esoteric and otherwise, all came together to affect the sound quality and system synergy.
After concluding my listening sessions with the Esoteric D-07 I reconnected my Berkeley Audio Design Alpha DAC and listen to some of the same music I had listened to during the review. Not only is this a sanity check for me but it also allows me to check the other components in my system to make sure they all sound as they should. Plus the $5000 Alpha DAC and the $4800 D-07 are definitely competing for the same consumers who are interested in a comparison of the DACs. As I always say, nothing is better than a personal audition in one's personal audio system. Please take my opinion as a single data point among many. Immediately after connecting the Alpha DAC I was back in sonic heaven. The three qualities that really stood out were the Alpha's superior separation of instruments, incredible detail at low volumes, and wonderful transparency. It was no contest in my current system.
Post Game Report
By now it should be crystal clear that I call things as I see them. I see the D-07 DAC as Esoteric's half-hearted attempt to enter the USB DAC market. Between the misleading manual, the mediocre USB implementation, and the unsatisfactory sound quality it appears as though computer audio was an afterthought to Esoteric. Like the USB portion of this DAC was a bolt-on feature added just before the DAC's release. It's also possible that the homogeneity of a pure Esoteric system with DAC, transport, and external clock may be what's required for best performance. Esoteric has not reached its current level of prestige and overall performance by making bad products. Even after my experience with the D-07 I can't conclude it's an all around bad product. My conclusions about its performance and sound quality are only valid to my ears through my audio system in my listening room. Again, use this review as a single data point among many. Writing-off the D-07 or any Esoteric product because of this review would do a disservice to anyone in the market for new components.
Verity Audio Fidelio loudspeakers, McIntosh MC275 amplifier, Richard Gray's Power Company High Tension Wires, Berkeley Audio Design Alpha DAC, Wavelength Audio Proton, C.A.P.S. server, Bel Canto USB Link, Halide Design Bridge, dCS Debussy DAC, dCS Puccini U-Clock, Kimber USB Cu, Kimber USB Ag, Benchmark DAC1 PRE, Kimber Select KS1011 Analog Cables, Kimber Select KS2020 Digital Cable, Kimber Monocle X Loudspeaker Cable, ASUS Xonar HDAV 1.3 Slim, Apple iPad, Sonic Studio's Amarra, M2Tech hiFace, Weiss Engineering DAC202, Lynx Studio AES16 Digital I/O Card.