EMM Labs introduced a new stand-alone digital to analogue converter at CES, the DA2. Within days of the introduction, the first production run had been sold out and a second begun. Now the second run is also spoken for. As technology advances, there comes a point when the existing hardware platform will no longer support future changes. I believe that this was the point that EMM reached with respect to their current digital to analog converter and what precipitated the need for the DA2. In any event, given that I replaced an XDS1 (early version) with the Esoteric P-02/D-02, I thought that it would be very interesting to pit EMM Lab’s latest top of the line transport TX2 SAC and the DA2 against my reference and EMM Labs agreed to provide units for review.
Technology and Design
The story of the EMM Labs DA2 Reference DAC is essentially the story of its designer Ed Meitner. Everything Ed has learned in his long experience with electronics and audio has contributed to the DA2 design: from the chassis to the power-supplies, the digital audio interfacing, the digital audio signal processing, the digital-to-audio transition, and the analog output drivers.
The DA2 power supply is a power-factor-corrected switching design, the latest in a 20-year history of advanced Meitner switching power-supplies. It is efficient, universal, and non-polluting; wasting little energy while leaving little measurable footprint on the AC line and other devices nearby. It keeps the electrical environment inside the DA2 utterly stable and noise-free no matter what is going on outside of it.
The machined aluminum chassis is substantial but appropriate; it is as massive as necessary to protect the circuit boards inside from disturbances outside and not more. It is vibration-damped and incorporates a unique “charge management system” which stabilizes the electrical field surrounding its sensitive audio circuits. This idea of providing what is appropriate and necessary is a basic tenet for all of Ed’s designs, as is the corollary to use the “right” part, not necessarily the most expensive or exotic.
All DA2 digital audio inputs are galvanically isolated (including the USB Audio) and sensed by the patented MFAST high speed asynchronous data acquisition system. MFAST is more immune to source jitter than conventional PLL-based AES and SPDIF receiver chips. Even for this peripheral function of data input reception, Ed’s dedication to perfection shines through in the use of custom circuitry rather than off-the-shelf chips.
Once captured and decoded, the audio bit stream is processed by the MDAT2 firmware algorithms in an FPGA. Filtering and dithering is optimized and minimized, re-sampling is never done, while the MDAT2 architecture performs a more complete avoidance of digital artefacting than apodizing filters can ever hope to do. This is seen in the incredibly perfect square-wave and impulse playback with no pre-ringing or post-ringing (see attached picture) – musical transients thus remain more pure and un-smeared than by any other method. MDAT2 neither adds nor subtracts from the audio data and lets you hear precisely what was recorded and mastered. The FPGA firmware is, of course, upgradeable as future refinements are made.
The heart of the DA2 playback system beats on the ceramic-composite 6-layer analog audio board – the revamped MCLK master clocking system. MCLK has a temperature stabilized and electrically protected time-base with sub-picosecond jitter and is twice as fast as previous EMM systems – both in clock-rate and in responsiveness.
This precise and stable MCLK drives two of Ed’s latest and fastest MDAC digital-to-analog conversion modules. These natively-DSD inherently-precise digital-to-analog-converters are naturally free of differential nonlinearities found in all ladder, ring, or hybrid converters whether they are monolithic chips or discrete resistor designs. By design, each discrete MDAC is balanced and matched in itself and to others to within 0.2%.
Together, the minimalist and least-harm philosophy of the DA2’s MDAT2, MCLK and MDAC modules recreate two pristine channels of balanced audio for the Meitner output drivers. Each channel has twin plus and minus matched circuit paths which perform gentle, balanced, passive output filtering while using minimal feedback. Leading to robust and powerful class-A balanced line-buffers delivering purest audio no matter what they are connected into.
- (Page 1 of 2)
- Next page →