- Written by Jason Victor Serinus
- Published on 28 January 2008
To begin my experiments, I removed the Theta Gen. VIII from the chain and used the DAC1 USB as my DAC/preamp. To set up, I connected my Theta Carmen II transport to the Benchmark DAC1 USB using a Nordost Valhalla 1.5 m balanced digital cable. I then connected my Nordost Valhalla 1.5 m balanced interconnect from the Benchmark's balanced outputs directly to the prototype VTL 450W monoblocks. The Benchmark's output was set to "Variable," which allowed me to control volume with its built-in 41-detent potentiometer.
I listened to a host of my favorite vocal, instrumental, and jazz test tracks, including Canteloube's Songs of the Auvergne (CBC Records) and Beethoven's Ninth Choral Symphony with the Cleveland Orchestra (DG). I also greatly enjoyed revisiting a recording included in my 2007 Christmas reviews, John Eliot Gardiner's live performance of J.S. Bach's motet, Singet dem Herrn ein neues Lied, BWV 225 (Soli Deo Gloria SDG 137).
No matter what I played, I was struck by the extraordinary amount of air in the presentation. On the Bach, for example, the air around the voices of The Monteverdi Choir was positively captivating. Transparency and clarity were also first rate, as was the timbre of voices of instruments. It was only in direct comparison with the Theta (which costs $10,000 vs. the Benchmark's $975 / $1275) that the sound of the Benchmark registered as thinner and less substantial. It was though midrange weight had been reduced, and colors dulled a bit. Voices were lighter, as though they had less body. There was simply more there there with the Theta.
However, and I say this with all sincerity, had I not known of the greater midrange warmth and weight that the Theta could produce, I would have been perfectly satisfied with the sound of the Benchmark. Its sound may be lighter, but it is extremely engaging and satisfying. I can well imagine that, had I still been using my old Theta Gen. Va and Bruce Moore preamp as my reference, I would have ended up preferring the far more up-to-date sound of the DAC1.
Next, I evaluated how well the DAC1 USB functions as a stand-alone DAC by connecting it to the analog preamp section of Theta DAC/preamp via a 1m length of Nordost Valhalla unbalanced interconnects. Setting the Benchmark's output to "calibrated," I again listened to the beginning of Bach's beautiful motet. The sound was markedly fuller than before. Although I noted a slight electronic halo around the oboe at the beginning of the third movement bass aria, the bass voice itself sounded quite natural. The organ also sounded very full, rich, and filled with portent. Images moved out from the soundstage, filling the room in a most gratifying three-dimensional manner. Images were also more rounded and colorful than when the DAC1's preamp section was in use.
Next, I sampled a promotional CD-R pre-release of Asturiana, an ECM recording of violist Kim Kashkashian and pianist Robert Levin playing songs from Spain and Argentina. (Review forthcoming). This disc has since been nominated for a 2008 MIDEM award in the classical category.
Although I was only listening to two instruments, my experience confirmed what I heard with the more complex Bach recording: using the DAC1 solely as a DAC, and pairing it with a high-quality outboard preamp, delivers a far more colorful, three-dimensional presentation in which sonic images have realistic weight. As was the case four years ago when I evaluated the original iteration of the DAC1, its DAC section remains superior to its preamp section.
To evaluate how the DAC1 can handle large, complex signals, I chose the first movement of Mahler's glorious Second Symphony, conducted by Ivan Fischer on a "Record-To-Die-For", DSD-native SACD from Channel Classics. Percussion was thunderous, cymbals exciting; everything sounded in correct proportion. Cellos were especially rich and full, almost chocolaty in their color. The sound was wonderful, complemented by an appropriately large soundstage. Yes, the bloom of the Theta Gen. VIII was richer still. But the difference between the DAC sections of the Theta Gen. VIII and the DAC1 was far less than the large price differential would suggest. I was mightily impressed.
The USB Experience
Although I have read copious reports that claim that computer hard disk drives produce far less jitter and thus better sound than expensive CD transports, the Theta Gen. VIII's lack of a USB input meant that I was unable to plug a computer into my sound system until the DAC1 USB came my way. Now, I was finally able to test the hypothesis.
First I used iTunes 7.5 (19) to burn a few choice CD cuts to my Apple Titanium Powerbook's hard drive at the slowest speed possible and without compression. Those cuts included two minimally scored, maximally transparent Latin jazz tracks from Marga Gómez's fabulous Chesky CD, Entre Cada Palabra, and the entire Berlin Philharmonic Orchestra performing "Mercury" and "Jupiter" on Sir Simon Rattle's recent, fabulously recorded EMI CD of Holst's The Planets. Talk about maximum contrast.
As you can see from the close up view of my equipment racks, I wasted no time in grabbing the Benchmark's USB cable and connecting one of the Powerbook's USB outputs to the DAC1 USB input. I used Nordost Valhalla power cables on the Theta Carmen II transport, Theta Gen. VIII, and Benchmark DAC1 USB, plugging everything into a Nordost Thor Power Distribution System. Though I had no way to use Nordost Valhalla to power the laptop, I went the cleanest route possible by using battery power. Nor did I have a way to replace the inexpensive USB cable that comes with the DAC1 USB with the same quality Nordost Valhalla interconnects that linked the Carmen II to the Gen. VIII.
Before playing, I carefully followed the instructions on Benchmark Media's wiki site. Using Mac OS X v. 10.4.11 and iTunes 7.5 (19), I opened the Mac's Audio Midi Setup and set "Audio Output" to 96000.0 Hz, 2ch-24bit. Note that I did so before opening iTunes, which is essential to creating the proper interface.
Happily, the DAC1 USB interfaces with Mac and Windows operating systems without need of external software. As soon as the DAC1 USB was connected the computer, powered up, and set to USB input, Audio Midi Set-up's various menus displayed "Benchmark 1.0" as a choice. After I set everything I could to "Benchmark 1.0," the interface performed flawlessly. (I surmise the reason that some Mac-equipped reviewers have been dissatisfied with the performance of the DAC1 USB may be the result of using earlier versions of OS X and iTunes).
Benchmark Media criticized earlier versions of iTunes for their lousy volume control, and urged DAC1 USB users to bypass the iTunes volume control by turning it all the way up. Happily. iTunes 7.5's volume control has greatly improved, enabling DAC1 USB users to choose an optimal iTunes volume setting. Because the DAC1's 41-step volume control is calibrated so that the smallest changes in volume (.5 db increments) are only possible between steps 20 and 37, it's best to adjust to iTunes' volume so that the volume control pointer on the DAC1 USB points to somewhere between 12 and 3 o'clock.
What I heard blew me away. First, replaying some of the selections I had heard earlier, and moving between the Theta Carmen II/Gen. VIII and the Apple/DAC 1 USB combo, I felt the sonic gap between the two DAC/preamps significantly reduced. It was a little painful to hear my Powerbook doing a better job than a Theta Carmen II transport that listed for over twice the Powerbook's retail price. But I could not deny what I heard: the sound of the Apple/DAC 1 USB combo was far superior to the sound of the Carmen II transport/DAC I USB interface.
Things got even better when, instead of inserting the Marta Gómez or Holst CDs into my computer's hard drive, I played the burns of the same tracks. Most noticeable was a softening of what remained of a hard digital edge. The sound became warmer and a bit more analog-like. I don't want to overdo this. It wasn't like listening to an SACD or an LP, but it was definitely a step up from listening directly from CD).
I trust I've made it clear how impressed I was by the DAC1 USB's performance. I can only imagine how better it would sound if, instead of the inexpensive stock USB cable supplied with the unit, I had used an aftermarket cable.