Fast FactsApplications: Studio, post production, field
Key Features: Up to 24-bit/192 kHz; remote source selection; monitor volume control.
Price: DAC1-MK2: $ 6,700; DAC1 (up to 96 kHz only): $5,900
Contact: Weiss Engineering/TransAudio Group at 702-365-5155, www.weiss.chProducts from Weiss Engineering have long been synonymous with mastering at the pinnacle of audio quality. Their Gambit series has literally redefined how mastering is done in the digital domain. The latest iteration of their digital-to-analog converter demonstrates that they are equally adept at the analog stage. The DAC1-MK2 not only breaks the mold for conversion quality, but also adds very useful features such as source selection, monitor volume control, and digital routing via remote control. The MK2 supports sample rates up to 192kHz and produces impeccable audio via a pure Class A discrete line output stage.
The DAC1 accepts three AES or S/PDIF formatted inputs on XLR connectors and one TOSlink input. Upon selecting a source, the analog out of the DAC is muted while a stable lock is achieved, usually in about three seconds. During this time the DAC will achieve a jitter-free lock due to its use of first-in-first-out RAM buffer controlled by a local, highly stable VCXO clock and proprietary DSP. The buffer completely isolates the DAC from incoming jitter while the DSP controlled crystal clock prevents overflow or underflow by slowly regulating the read speed to match the incoming data. The bottom line is that the conversion quality is immune to any detrimental effects due to cabling, poor system clocks, or the cumulative jitter of daisy-chained digital devices. The lock range is ±80 ppm and, as long as the data reaches the DAC correctly, external jitter effects are absolutely nil.
The three XLR digital inputs have mirrored digital outs allowing the converter to pass along data, but these are merely bit-transparent retransmissions and are not subject to the dejittering process. Digital Output 3 can be selected to transmit the currently selected input enabling the unit to act as a router. As currently shipped, the DAC1-MK2 will accept single-wire inputs up to 96 kHz but will accept only dual-wire format for 176.4 kHz or 192 kHz signals. The company states it will release a field-serviceable upgrade kit to accommodate single-wire 4Fs data in early 2006.
A number of high-end design techniques contribute to the DAC's superb performance. In addition to the all-important jitter-eliminating buffer arrangement, a special oversampling method is employed to up-convert the audio data to 8Fs prior to conversion. This is done in two stages - the first stage, which is the most critical, is a 2X upsampling by Weiss's own proprietary ultrahigh quality DSP. The next stage, a 4X upsampling, is done on the Analog Devices converter chip itself. The DAC1 also utilizes a correlation technique employing two DAC chips per channel. This raises the signal level by 6 dB while the level of uncorrelated artifacts increases by about only 3 dB, for a net gain of 3 dB in signal-to-noise. Finally, the analog output consists of a minimalist circuit built with Analog Devices AD797 op amps driving a pure Class A discrete output stage. The output impedance of only .2 ohms, carefully designed to avoid oscillation, is powerful enough to drive a small set of speakers. The low-impedance high-current output topology renders the sound of the DAC1 all but immune to the effects of cabling and loading by the equipment on the receiving end. Just think of all the money that can be saved by avoiding $1,000/meter wire!
The DAC1 can also be used as a digital monitor volume control and four-way digital source selector. Level control changes are done in the digital domain and are properly dithered to 24-bit resolution. While not applicable in every situation, this capability does allow use without a preamp resulting in D-to-A monitoring about as pure and direct as you are likely to get. A 15-pin D-sub rear panel connector permits the end-user to build a remote with level control and indication. Weiss also offers to custom build a remote control accessory to the user's specifications.
Front panel indicators signal the active source, the sample-rate and actual bit-depth of the incoming data. The bit-depth indicator is useful for verifying the integrity of the input signal. On the rear panel are two small switches. One configures Digital Output 3 as the source-selected pass-through. The other drops the analog output level down by 12 dB for interfacing with equipment operating at -10 dB levels. Final output level adjustments are made with two multiturn trim pots on the front panel.
I will flat-out say that the DAC1-MK2 offers resolution, detail and impact that I did not think possible in a digital-to-analog converter, and it does so while sounding beautiful. Compared with my quite respectable reference DAC there were startling improvements. Where there used to be a more homogenous blend of bass drum and bass guitar, there now was the unmistakable sound of the beater hitting the skin, the shape of the shell, and possibly even the fingers scraping the windings on the bass strings. When switching at matched levels to the Weiss DAC1, the soundstage widened, warmth filled in, the texture of the sound became smoother, and hidden details emerged. Switching back to my reference converter, a layer of gauze covered the sound and there was a slight sense of stress as I tried to recover qualities I was no longer hearing. Back on the Weiss, I felt myself relax as though a constant, unconscious effort was no longer necessary. These differences were dramatic and not in the least bit subtle.
The majority of mixes these days are printed to digital files. Consequently, utilizing analog hardware in final mastering requires two additional conversions, the most critical of which is the digital-to-analog conversion - what isn't reproduced can never be recaptured. I installed the Weiss DAC1 as the source for my analog mastering chain and recalled some projects that I had done without it. Blind or sighted, there was no contest when A/B-ing the results before and after. The focus of the sound was obviously softened in the nonWeiss versions.
In listening to some CDs mastered more than a decade ago, before overprocessing became de rigueur, it was revelatory how much information had actually been encoded in the lowly 16-bit/44.1kHz format by the A/D converters of the day. Albums such as Janis Ian's Breaking Silence or Explorations by the Bill Evans Trio played through the DAC1 sound as analog as real analog. Shannon and Nyquist were right, it's just that that there's much more quality in 16-bit/44.1 kHz than most listeners will ever hear.
The song says "You don't know what you've got 'til it's gone." With digital audio, you just don't know what you've got - at least not with anything less than a converter like the DAC1.
Fast FactsApplications: Studio, post production, field