DACs

Benchmark DAC1 USB

ARTICLE INDEX

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Introduction: A Return Visit

I expect that many Secrets readers will already be familiar with the Benchmark DAC1. Initially brought to my attention by recording and mastering engineer Bob Olhsson, then by fellow audiophile reviewer/music critic John Marks, the Benchmark's amazingly high level of performance for a unit priced well under $1000 immediately seized the audiophile community's attention when it first came on the scene well over four years ago.

My initial review of the DAC1 Digital-to-Analog Converter appeared in these pages toward the end of 2003. As I wrote at that time, Allen Burdick of Benchmark Media explained that the DAC1, then retailing for $850, was designed with the recording engineer in mind. With so many low price studios churning out flat, harsh, one-dimensional digital recordings, Burdick's goal was to provide studio engineers with a low-price option for radically improving recorded sound.

While I expressed some reservations about the DAC1's performance in my initial review, I found myself ultimately agreeing with what critics were saying. "The DAC1 is a major achievement," I wrote in my conclusion. "Far more than a taste-of-the-high-end toy, it is a bona-fide audiophile product whose sound is astonishing for its price."

Since then, the DAC1 has continued to make waves in the audiophile community. Benchmark Media has responded accordingly, embracing the home entertainment market by significantly upgrading the unit's performance while keeping the cost of the basic unit under $1000.

Perhaps a year ago, Rory Rall of Benchmark Media contacted me about revisiting the DAC1. Rory not only claimed that its sound had greatly improved, but also enticed me with the news that a new version of the DAC1, the DAC1 USB. This new model includes a USB port for connection to computers and hard drives. The USB input is compatible with Windows Vista/XP/2000 and Mac OS X, and does not require driver installation or system configuration.

Given that my main system's Theta Gen. VIII DAC/preamp does not have a USB port, I leaped at the opportunity to connect my Apple Powerbook laptop to my main system. I was also enticed by the idea of adding an external DAC to my office iMac, which is connected to the marvelous Audio Engine 5 self-powered speakers. Of course, being who I am, the leap was conducted in slow motion. Many, many, many moons later, amidst more deadlines than I wish to recount, I began unpacking the DAC1 and appreciating all that it has to offer.

Specifications

  • Design: Dual Differential 24/192 DACs
  • Digital Inputs: Three Coaxial, One Toslink
  • Analog Outputs: One Set XLR, One Set RCA
  • MFR: 20 Hz - 20 kHz, - 0.1 dB
  • THD+N: 0.00056%
  • Dimensions: 1.7" H x 9.5" W x 9.33" D
  • Weight: 3.5 Pounds
  • MSRP: $1,275 USA
  • Benchmark Media

A Complete Re-evaluation

Comparing the reference system I employed for my initial DAC1 review to what I have four years later, the differences are significant. My reference transport, DAC, preamp, amplification, and power treatment have all greatly improved. I'm also using a different pair of speakers, Eggleston Works' The Nines, which will receive copious praise when I review them in a few months.

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Power itself has taken a mafjor step forward thanks to a dedicated line monitored by new circuit breakers rather than an ancient fuse box. The room too has changed for the better, morphing from a 14.5' x 17' living room with a ceiling height of 8' to a much larger, far more open space that truly allows a system to shine. The only constants over the past four years are the interconnects, speaker cables, racks, brass cones, some of the pillows in room corners, and a few invaluable tweaks whose mere mention drives some folks batty. That I now also use Shakti Hallographs and the Marigo Signature 3-D mat version 2 may in fact drive my harshest critics completely over the edge. It's a shame really, because if they held it together long enough to try the DAC1 USB, they would probably stick around for the long haul.

In short, my standard of comparison is far higher than four years ago. I'm able to hear a lot more of the DAC1s strengths and weaknesses, and compare it to a far more expensive, near state-of-the art DAC/preamp. As you will soon read in detail, I liked what I heard.

Options and Features

The DAC1 comes in two models, the basic DAC1 ($975) and DAC1 USB ($1275). Save for the addition of the USB input, the two units look, sound, and measure alike. Therefore, my discussion frequently refers to the sound of the DAC1.

Three faceplates are available for the DAC1 USB: black, silver, and black rack mount. The latter has a longer faceplate with four holes in the corners for rack mounting. The top of all units is black.

The front of the DAC1 USB includes, from left to right, an input toggle switch; two HPA2™ high-current, "0-Ohm", high-output ¼" headphone outputs; and a calibrated volume control. The headphone outputs are always on, and always controlled by the front volume control unless the unit's internal jumpers are called into play.

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The DAC1 USB's rear includes, from left to right, two unbalanced RCA outputs; an output level switch that toggles between "Calibrated" (near full-volume fixed output), "Off" (analog outputs are muted and headphone outputs remain active), and "Variable" (volume is adjusted by the front panel volume control); 10-turn calibration trimmer screws located to the left and right of the output level switch; two balanced outputs; four digital inputs (AES/SPDIF; AES, Toslink, and USB); and a 3-prong AC IEC connector plus a fuse drawer that holds two 5 x 20 mm 0.5 A 250 V Slo-Blo® fuses. The fuse drawer also features a voltage selector switch that can be set to either 110 or 220.

The DAC1's input accepts sample rates from 28 to 195 kHz in coaxial, XLR, and optical modes, and up to 96 kHz in USB. Maximum input word length is 24 bits. Digital input impedance is 110 Ohms on XLR input, and 75 Ohms on Coaxial input. Balanced analog output impedance is 60 Ohms, and unbalanced analog output impedance is 30 Ohms. Headphone output impedance is <0.11 Ohms.

Further stats are readily available by downloading the DAC1 USB's manual (currently in Revision C form) from the Benchmark Media website.

Installation

For use with an outboard transport, installation for the DAC1 USB is as simple as can be. Connect a digital cable from the transport to the DAC1 USB's appropriate input, then toggle the front panel input switch until the input light indicator(s) remain(s) on without blinking. Next, decide if you're using the unit solely as a DAC, or as a DAC/preamp. If using as a DAC/preamp, switch the output level switch to "variable," and connect output cables from the DAC1 USB to your amplification. If using solely as a DAC, switch the output level switch to "calibrated," connect output cables to a separate preamp and complete the chain with amplification and speakers.

Use with a USB output device is just as simple, at least when it's a Mac. (I have not tried the unit with the Windows operating system). The key to optimal sound is which versions of the Mac operating system and iTunes you're using. Because optimal configuration changes each time Apple issues with a new revision to its operating system or iTunes, checking Benchmark's online "Audio Information Center" is essential.

I will discuss my own extremely positive experience with USB set-up and playback further on in this review.


Listening

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.

benchmark-dac1-usb-figure-6.jpgAs 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.


The Icing on the Cake

The ultimate mind-blower came when I brought the DAC1 USB upstairs and connected it to my office computer. This system, consisting of an iMac5.1 equipped with a 2.16 GHZ Intel Core 2 Duo processor and Audio Engine 5 self-powered speakers, had never before played music through an outboard DAC.

benchmark-dac1-usb-figure-8.jpgAgain, set-up was as simple as can be. It took but a few minutes to plug in the DAC1 USB, adjust Audio Midi set-up, find optimal positioning for the volume controls, and start listening. Of course, to get the best sound possible out of the system, I used a Nordost Valhalla power cable on the DAC 1 USB. (I know. The power cable alone costs twice the price of the DAC1 USB). I also took advantage of Harmonic Tech Magic One interconnects and some ancient High-Wire speaker cable. Finally, I put Ganymede ball bearing supports under the DAC1 USB, and a Shakti stone on top.

As the ultimate tweak, I capped it all with a Las Vegas vintage plastic Elvis. To insure that the beautifully clear, detailed sound I was hearing was not a result of the DAC1 USB channeling the spirit of Elvis, I also auditioned the unit with Elvis on the other side of the room, his back turned to the proceedings. I could hear no difference in sound. If Elvis was still channeling, he must be affecting every component in the house in equal measure.

benchmark-dac1-usb-figure-9.jpgOkay. You've heard me gush aplenty already. Suffice it to say that the DAC1 USB produces such better sound than the iMac/iTunes built-in sound processor that comparisons are preposterous. Once I heard how good my new set-up sounded, I realized that I could never return the DAC1 USB to Benchmark. I bought the review sample.

Conclusions

The Benchmark DAC1 USB is far more than a lightweight, inexpensive DAC/preamp that performs remarkably well for the price. It is the real thing, a bona fide hi-end product capable of elevating a decidedly mediocre sounding system to a level that audiophiles can be proud of. Beautifully engineered, built to last, and incredibly easy to set-up and operate, the DAC1 USB is a must-audition, hard-to-resist product.

In my case, resistance was futile. Count me among the many satisfied Benchmark DAC1 USB owners.


JASON VICTOR SERINUS REFERENCE SYSTEM
Digital Front End
Theta Carmen II CD/DVD transport
Theta Gen VIII DAC/Preamp
Benchmark USB DAC-1 when Apple Titanium Powerbook is in use

Amplification
VTL 450W tube monoblock prototypes
Jadis DA-7 Luxe with GE 5751 Jan and Jan Philips 5814A tubes and cable from Pierre Gabriel

Loudspeakers
Talon Khorus X speakers MK. III (with latest upgrade and Bybee Quantum Noise Purifiers)
Eggleston Works The Nine (here for review)

Cabling
Nordost Valhalla single-ended and balanced interconnects
Nordost Valhalla balanced digital interconnects
Nordost Valhalla bi-wired speaker cable
Nordost Valhalla Power Cables
Elrod EPS-2 Signature power cables

Power
Nordost Thor Power Distribution System
ExactPower EP15A equipped with outlets from Sound Applications and other mods
IsoClean or other audiophile grade fuses in most components
Dedicated line for system

Analog
Clearaudio Emotion turntable with Satisfy arm
Benz MC-Gold phono cartridge
Classe 6 phono preamp

Accessories
Ganymede ball bearing supports
Michael Green brass Audiopoints
Audiophile grade fuses in all equipment.
Acoustic Resonators
Michael Green Deluxe Ultrarack, Basic Racks and Corner Tunes
Echo Buster and Corner Busters
Shakti stones on transport, DAC, amps, and circuit breaker
Four Shakti Hallographs
Bedini Quadra Beam and Dual Beam Ultraclarifiers, Audioprism CD Stoplight,
Marigo Signature 3-D Mat v2; Ayre demagnetizing CD.

Main System Room Dimensions
Our living room is 24.5' deep, 21.4' wide in the listening area. It's big enough to accommodate 16 members of the Bay Area Audiophile Society, positioned in four rows of four seats each. The distance from the front door to the end of the dining room is 37', with sound extending far to the left and right of the speakers thanks to an 8.33' wide archway opposite the right channel speaker. Ceilings are 9' high with heavy wooden crossbeams, each 17" in height. Heavy curtains cover windows behind the sound system. Floors are hardwood and carpet in front of the system, and hardwood elsewhere. Walls in the living room are a combination of plaster and wood, with a large granite fireplace in the rear. The dining room is all plaster. There is RoomTune and Echo buster treatment in corners, and either an Echo Buster or heavy tapestry at the two side wall first order reflection points.

Upstairs Second System:
Genesis I-60 Integrated amp
Von Schweikert VR-4jr. speakers
Proton 26" non-HD anything but flat decidedly undigital TV
Basic Pioneer DVD player
Assortment of WireWorld Gold Eclipse 5, Harmonic Tech Magic One, and Nordost Valhalla and Tyr cabling; Elrod EPS-2 Signature and AudioPrism SuperNatural S2 power cables

Computer System
Apple iMac G5
Benchmark DAC-1 USB
Audio Engine 5 self-powered speakers
Nordost Valhalla Power cabling
Harmonic Tech Magic One interconnect
High-Wire speaker cable
Ganymede Ball Bearing supports


Also on hand and sometimes used:
PS Audio P600 Power Plant power synthesizer with MultiWave II
Interconnects: WireWorld Gold Eclipse 5 and Gold Starlight 5 digital, Harmonic Tech Magic One, Acoustic Zen Silver Reference II balanced, and Nirvana BNC-terminated digital.
Power cables: Elrod EPS Signature 3 plus EPS 1, 2, and 3; WireWorld Silver Electra 5; PS Audio X-treme Statement; and AudioPrism SuperNatural S2.