August 2012

EMM Labs DAC2X Stereo D/A Converter
Pulling out all the stops.
Review By Phil Gold

  Three years ago I reviewed Ed Meitner's DAC2, a superb unit by the standards of the time, and today we are looking at what progress has been made since then. Is it just gilding the lily, or are there substantive improvements to justify the $15,500 price tag?

Before we start, remember that Ed Meitner has been perfecting DACs for three decades now, and analog circuitry for four decades. He's a perfectionist who has rethought every single element of DAC design, from power supply to input section, from converter to analog output, and was instrumental in the design of the DSD/SACD format. He also developed the first Jitter Analyzer, which he made available even to his competitors (now that's class). His designs have been widely adopted in studios around the world, and his consumer products, manufactured in Calgary, Alberta have been instrumental in raising the standards of digital performance to unprecedented heights. Where many manufacturers buy components off the shelf – DAC chips, analog output stages, power supplies, low jitter clocks and so on, Ed designs and builds these all in house. He does this because the parts he could buy do not reach the standards he sets for himself. If that means building a discreet converter (the only pure 1 bit converter in use today), so be it. The proof of the pudding is in the eating. Without doubt the XDS1 is one of the finest if not the finest CD player in the world today, and I have chosen it is as my reference front end. You may wish to see my 2010 review of the XDS1 before reading the rest of this one. My XDS1 sounds even better today as it has been updated to the latest specifications through firmware updates and circuit changes (for example, to allow 24-bit/192kHz inputs).

The DAC2X looks almost the same as the DAC2 from all positions except the rear view, where the PDAI input has changed format and the high-low output switch has disappeared. Outputs are now a standard 2V unbalanced, 4V balanced. What was once labeled PC-Audio is now labeled USB-Audio and everything else has moved around. This USB input now supports DSD streaming using DoP 1.0.

EMMBut the true precursor for the DAC2X is not the DAC2, despite all appearances. It's the XDS1 CD/SACD Player ($25,000), EMM Labs' top of the line unit, a digital source which has become this reviewer's reference and one that has won accolades all over, even from those few who had not been won over by previous efforts from this specialized Canadian manufacturer. The XDS1 introduced the encapsulated XPower System, the proprietary high speed clock module (MCLK-1) which it is claimed sets new records is sub-picosecond jitter measurements, and a single discrete class A output stage with the shortest possible signal path. The XDS1 also introduced significant refinements to the MFAST (Meitner Frequency Acquisition System) asynchronous input mechanism which made its first appearance in the DAC2.

DAC2 Back

DAC2X Back

The DAC2X dispenses with the drive mechanism and all the logic and power supplies required to support the drive functions but adds a USB input. All inputs now support up to 192K/24bit signals and the special EMM OptiLink optical input (which used to be known as AT&T optical) also supports DSD. The XDS1 inputs have been upgraded similarly since its introduction, but the USB input is not available on that unit.

Let us look closely at the DAC2X and see what has changed compared to the XDS1. There are significant changes in the modular switching power supply, now shared across the entire product line. While the switcher itself (first seen in an 8-channel DAC made for the professional market) is unchanged, the voltage filter has been redesigned. Power from the wall is first converted to high voltage DC in a PFC (Power Factor Correction) circuit, then the switcher produces multiple low voltage supply rails for the various analog and digital circuits. Voltages are locally filtered (regulated) on each circuit fed by the switcher, and it is these low voltage rail filters that were changed. I understand the power supply is massively over-specified even for the XDS1 with its additional circuitry for control loading and motor drive, producing twice the maximum required output, so here it is just coasting. Any good designer will tell you how fundamentally important a good power supply is to any electronic component, and I am assured that this power supply is cleaner on both the output side and in what it returns to the power outlet than any linear power supply. This makes the DAC2X fully CA compliant.

The input circuitry has also changed to accommodate the additional USB input. Circuits built for AES/EBU and EMM OptiLink were revised to provide additional isolation to protect the unit from jitter or other pollution coming from the USB connection as much as possible. All inputs are clocked asynchronously using MFAST (Meitner Frequency Acquisition System) to the ultra low jitter clock in the DAC2X. MDAT (Meitner Digital Audio Translator) technology is used to upsample all signals to 2x DSD frequency in the same discreet dual differential balanced MDAC as in the XDS1, but the discreet single gain stage Class A analog output circuit is a later generation to the XDS1's output and is said to be responsible for even higher resolution than the earlier design.

I asked why discreet output circuitry is used instead of the more popular Op amp topology. Ed Meitner used op amps in the design of the earlier CDSA CD/SACD player, but switched to a discreet design where a lower level of feedback would be necessary to keep distortion to a minimum.

The new Meitner MA1-DAC is a less expensive implementation of the no compromise DAC2X. The differences are in the output stage, where a simpler design is used, in the cabinet materials which are less costly and substantial, and in the glass-epoxy circuit boards used in place of the ultra expensive ceramic boards used in the DAC2X. The power supply sub system regulation is not as sophisticated and the EMM OptiLink (aka AT&T) for DSD signal input has been dropped. The DAC2X uses some carefully selected and hand matched high cost parts where the Meitner unit may use less expensive parts. Most other internal elements are shared between the two models. A credit card remote with simple source selection replaces the DAC2X's machined aluminum which offers full control over the partnering EMM Labs Transport (TDS1 or the new TDSX) plus source switching, mute and polarity. The Meitner DAC retails for around half the price of the DAC2X and may be just the ticket for those who aspire to this level of performance on a more affordable budget.

EMM Labs has also introduced a new partner for the DAC2X if you are looking for a suitable disc drive. The TSDX replaces the TSD1. It is best thought of as the XDS1 player without the digital conversion and analog output stages and it features an Esoteric UMK-5 CD/SACD mechanism. The EMM OptiLink input is the best way to connect these two boxes, and the only way to get the DSD stream directly from drive to DAC without first having to convert to PCM format. It's a very slim and flexible optical cable and naturally avoids all grounding issues as no electrical current is involved in the transmission.

Given its heritage, you'd expect the DAC2X, when driven by the XDS1 through the EMM OptiLink connector to sound very similar to the XDS1 through its own built in DAC. In fact it was very difficult to tell them apart. Time after time my A/B comparisons, achieved by switching the input from balanced 1 to balanced 2 on the reference EMM Labs Pre 1 preamp, yielded almost identical results. To really differentiate I had to play whole movements of complex music. Here I found the DAC2X to hold a slight edge in the coherence of the soundstage and the texture of individual instruments. Let me say at once that the XDS1 is superlative in its own right, and with the latest upgrades to hardware and firmware I would put it significantly ahead of the best I've heard from any other manufacturer. Play a superb recording like the Naxos CD of Shostakovich's 10^th symphony and it's gob-smackingly good. The resolution is to die for, the weight and bass impact stunning, the imaging huge and precise in each axis, while nothing can touch either the purity of its voice or the presence and color it achieves. I would be extremely pleased if the new DAC could match that, but it seems to have pipped it at the post by being even more musical and captivating. But please believe me when I say I have never heard two different components that sound so much alike.

Now you may have expected your reviewer to have "golden ears", blessed with the ability to notice the tiniest aural differences. Sad to say, that's not me. What I can do for you is to try out some interesting components in a very high resolution system with a variety of material and an appreciation for what live music should sound like. Many of the recordings I use are by artists I've heard in the flesh. Sadly not Miles Davis, not The Beatles, but The Stones, Sonny Rollins, The Stones, Dylan, Paul McCartney, Pollini, Haitink, Ella Fitzgerald, Buena Vista Social Club, Leonard Cohen and many more. I can remember not the precise sound they achieved but the effect they had on me, the thrill, power, delicacy, frailty. I try to judge the equipment that passes through my hands by its ability to recreate that excitement. If that sounds purely subjective to you, you're right, so I do also talk about some of the more objective elements of the sound, but you really need both sides and the degree to which I'm swept away is the more revealing measure in my book. I have this enormous passion for great music which I hope I can use successfully to discern the best equipment. I may be in the next room and I can still tell a great pair of speakers from a very good pair. You don't need precise measurements or a lot of words to do so. Either it captures the musical essence or it doesn't.

With digital sources, EMM Labs and Meridian have the secret sauce that other equally expensive or far more costly gear has often lacked. I can't tell you if it is resolution or bandwidth, but I can tell you it's in the dynamics, the stability of the image and the instrumental color. I believe you can trace this to the quality of the power supply and the purity of the output stage (dynamics) and the accuracy of the phase information and transient response (the elimination of jitter, the DAC implementation and the filtering). But in truth I don't care what the cause is, I'm most interested in the effect. If I could point you to a less expensive DAC that can sound like this, I'll be very happy to. Perhaps the Meitner DAC (which I haven't heard yet) will do the trick. For the moment I will just say that this is a truly satisfying DAC, capable of extracting the maximum out of both Redbook and high resolution sources, PCM and DSD based, and if you inhabit a world where you can afford the price of a small car (with its own built in DAC) for a single audio component, go for it. I doubt you'll hear better than this -- I haven't.

Manufacturer's Comment
EMM Labs would like to thank Phil Gold for a truly excellent review. Phil's conclusion makes us all at EMM Labs truly proud that our efforts to further raise the bar and make converters the way that we believe they should be made is justified.

Shahin Al Rashid
Director of Sales

Specifications
Type: Stereo solid-state DAC unit
D/A Conversions: Two-channel PCM to analog, 2-channel DSD to analog
PCM Input Frequencies:44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4k, 192k 
DSD Input Frequency: 2.8mHz, 5.6mHz
AES/EBU Input: 1 Connector, asynchronous
S/PDIF input: 1 Coax, asynchronous
TosLink S/PDIF Input: 2 Optical connectors, asynchronous
EMM OptiLink Input: 1 high speed glass connector for 2 active channels
USB Input: 1 Connector, asynchronous
EMM Expansion Port: For future digital inputs
Remote Control: Infrared, aluminum, controls matching drive TDSX.
Balanced Output: 300Ω XLR pin 2 hot, 4V 
Unbalanced Output: 150Ω RCA, 2V 
Phase Switch: Positive or negative output phase
Power Supply: Power Factor Corrected
Voltage: 100V/115V/240V 50/60 Hz - Factory set
Dimension: 43.5 x 40 x 9.2 (WxDxH in cm)
Weight: 26.4 lbs.
Warrantee: 5 yrs
Price: $15,500

Company Information
EMM Labs Inc
119-5065 13th St SE
Calgary, Alberta
Canada T2G 5M8

Voice: (403) 225-4161
Fax: (403) 225-2330
E-mail: sales@emmlabs.com
Website: www.EMMlabs.com