DAC1

One of my regrets in moving away from the Los Angeles area has been leaving behind a wonderful group of audio enthusiasts. We would meet at my home once a month to hang out with new audio toys. It was cool to share thoughts about the gear and to introduce each other to new stuff. I thoroughly enjoyed the friendship, camaraderie, and genuine understanding that we had. After all, audiophiles are a strange bunch. Just try discussing how the midrange of your new CD player is so much smoother and more organic sounding with your coworkers when you meet at the water cooler! If you've tried, you probably watched them scatter back to their desks. All this time you thought it was because you were the boss! With Los Angeles and Orange County traffic as horrible as it is, it's no surprise that not many of my audiophile friends make the one-and-a-half-hour drive to hang out anymore.

While I still miss my audio buddies, a new door was recently opened to me by PFO's editor in chief, Dave Clark. He mentioned that fellow PFO reviewer Jeff Parks lived within a stone's throw of my new home. Jeff called me out of the blue one night to introduce himself. Just knowing that there was someone else in the area that shared my interest in audio was a shot to the arm, so I invited him over. Since his CD transport was in the shop for upgrades, he asked if I would be interested in reviewing the Benchmark DAC1 that he had for review but was temporarily unable to use. I recalled reading positive things about this budget-priced DAC, and since I like to focus on getting the most performance for the least amount of dough, Jeff did not need to work hard to get me interested in reviewing the piece.

The Benchmark DAC1 is a two-channel, 24-bit/192 kHz, upsampling D-to-A converter featuring the company's UltraLock^TM technology. UltraLock^TM is a very low jitter conversion clock. Low jitter is essential for accurate 24-bit audio conversion. Most converters use a single-stage Phase Lock Loop or PLL circuit to derive their conversion clocks from AES/EBU, Wordclock, or Superclock reference signals. Single-stage PLL circuits provide some jitter attenuation above 5 kHz, but none below 5 kHz. Unfortunately, digital audio signals usually have the most jitter at 2 kHz. As a result, these converters only achieve their rated performance when driven by very low-jitter sources, through very short cables, and are unlikely to achieve better than 16-bit performance.

Better converters generally need a two-stage PLL circuit to filter out more jitter. Theoretically, a two-stage PLL can remove enough jitter to achieve accurate 24-bit conversion, but in reality, since not all PLL circuits are created equal, many do not remove enough low-frequency jitter. Another weakness of two-stage PLL circuits is that they often require several seconds to lock on to an incoming signal, and may fail to lock when jitter is too high or when the sample frequency drifts. UltraLock^TM converters offer 100 percent immunity from interface jitter under all operating conditions. They easily exceed the performance of two-stage PLL converters, and are free from their slow-lock or no-lock problems. UltraLock^TM technology also isolates the conversion clock from the digital audio interface clock. For further information or comprehensive specs, refer to Benchmark's website. 

Benchmark is best known for their gear for recording professionals, and one look at the DAC1 reveals that it is designed with the recording engineer in mind. The $975 unit has an unassuming black metal chassis with an aluminum faceplate that has rack mount holes. It is not beautiful looking, but it is functional. In the front, there are two headphone jacks driven by Benchmark's HPA2^TM high current headphone amplifier, which is capable of driving a variety of headphones while delivering less than 0.0003% distortion. On the far right is a gain control for the headphone jacks. The unit is designed to interface directly with power amplifiers and powered studio monitors, without the need for a preamplifier. If you flip a rear-panel toggle switch to the Variable position, the same knob can be used to control the output level of the balanced and unbalanced analog outputs, also in the rear. The DAC1 has three digital inputs (balanced XLR, BNC coaxial, and optical) that can be selected by flipping a toggle switch in the front of the unit, next to blue and red LEDs that signal the unit's status. There are also two 10-turn calibration potentiometers that are accessible from the rear panel with a small screwdriver. The trimmers provide 2 dB of adjustment per rotation, with a total range of +9 to +29 dB. Rounding out the rear panel is a 15A IEC inlet, which allows experimentation with aftermarket power cords.

I compared this little $975 DAC to my Perpetual Technologies front end with the P-1/A interpolation and upsampling engine feeding my ModWright Level II P-3/A 24/96 DAC, both powered by the Monolithic P-3 power supply and connected with Revelation Audio Labs Prophecy I²S interconnects. This setup costs nearly three times as much as the DAC1. I hooked the DAC1 up to my Audio Alchemy DDS-Pro transport with Argent Audio Jaden Signature digital coax cable. For the analog outs from the DAC1, I used my new reference interconnects, the CryoTweaks Silver Reference MkIIs, terminated with the new WBT Nextgen plugs. Since the DDS-Pro has a separate I²S output that is only compatible with my P-Tech setup, I was able to compare the two DACs by connecting them to separate preamp inputs, then simply turning the selector switch back and forth. The one thing that made the comparison a little difficult was the fact that the P-1/A reduces volume by 6dB to give it the necessary headroom for its speaker correction software, so I had to adjust the volume to ensure that I was listening at the same levels.

At first listen, the Benchmark DAC1 amazed me. Everything about it was better than my P-Tech setup! It had better resolution, better bass, better dynamics, better air, and it sounded more open. I was shocked. I did not think the Benchmark would deliver the same level of performance for a third of the price. I was also running the P-Tech setup in I²S format, which is supposed to be superior to any other digital format with respect to jitter. While the DAC1 was not a huge step beyond my P-Tech rig, it was noticeably better, and because of its price I decided to sell my digital gear and reduce the number of boxes from three to one. Because the Benchmark has a volume control, I also began wondering if I could eliminate the preamp from the signal chain, but while the preamp section in the DAC1 is pretty good for the money, it could not compete with my Aragon Aurum. Although running the DAC1 directly to my amplifier did increase the transparency and openness of the sound, the soundstage suffered without the Aurum, and the background was not as black. Piano notes sounded hard and icy, and bass notes were lacking in control. The preamp section of the DAC1 is not poor. In fact, it compares favorably to some preamps I have owned in the past, some of which cost more than the DAC1.

During this period, my P-1/A was in the shop getting new speaker correction software installed for my Onix Reference 1s. I was kindly loaned the P-1/A with which I made my first comparisons, which had a beta version of the software that I discovered had some issues only after my own P-1/A was returned. Compared to my updated P-1/A, the DAC1 no longer held the upper hand. Thoroughly confused, I decided to start over, and removed the P-1/A in order to compare only the two DACs. I still used the digital coax from my transport to feed the DAC1 and the I²S output from the transport to feed my P-3/A, as this enabled me to again plug each DAC into its own preamp input and achieve direct comparisons by toggling between the two inputs. 

This time, drawing a conclusion was much more difficult. The two DACs sounded so similar that hearing a difference was nearly impossible. It was so close I had to enlist the help of my wife, who concluded that if she was not critically listening, both were equally enjoyable. Only after listening intently did she draw the same conclusions that I had drawn earlier. It is important to note she had no knowledge of which DAC was being played—they were referred to only as source A and source B. 

I switched back and forth numerous times before determining that the P-3/A had a slight upper hand in clarity, separation, soundstage depth, background noise, naturalness, and bass control. The DAC1 was a bit splashier, a bit colder, and a bit sloppier in the bass. The DAC1 again sounded more open in the highs. The fact that the Benchmark's sound was so close to that of my reference DAC is remarkable, since the P-3/A is not only more expensive, but uses a superior, low-jitter I²S format. This would certainly support Benchmark's claim that the DAC1 exhibits extremely low jitter.

Next I reconnected my P-1/A with the latest speaker correction software. The P-1/A further eliminated some of the digititis that was present before. Out of curiosity, I decided to try the P-1/A with the Benchmark DAC1. I did not feel that the Benchmark benefited in any way. If anything, I felt that it sounded more constricted. Some of the sparkle and life had been sucked out of it.

While I am not a big headphone fan, I experimented with the DAC1's headphone output and my Sennheiser HD535s. My experience with headphones, aside from my own, is limited to the Sennheiser HD-600s, the AKG K1000s, and a Stax rig that I heard at CES. Compared to these, my Sennheisers driven by the DAC1 lacked body and emotional engagement. I do not know whether this is due to my headphones or the amp built into the DAC1. Of course, the headphones and headphone amps I heard at CES cost substantially more than the DAC1 and my Sennheisers.

Benchmark has produced a fabulous product at an astonishing price. Considering that I had to strain mightily to hear differences between it and my reference digital front end, which cost nearly three times as much, speaks volumes about the DAC1's value and performance. Finally, the built-in headphone amp and volume control eliminate the need for a preamp for those on a tight budget. Bravo to the DAC1 for setting a new benchmark! Fown-Ming Tein

I like to shop at the Nordstrom Rack. I love getting a good price on good stuff. It makes me feel like I'm living as large as anyone else, even if my pocketbook suggests differently. Who doesn't? In truth, some of the clothes are made specifically for the Nordstrom Rack, and have never seen the light of day at the mother store. When it comes to audio, everyone wants to think that their system gets them as close to the original event as the most expensive gear, and that the only difference between their components and the big-buck ones is fairy dust. This brings me to the Benchmark DAC1. Is this Stereophile Class “A” product as good as other Class “A” products?

Fown-Ming Tien wrote the initial review of the DAC1, and rather than recap the details of its construction, layout, etc., I will talk about how it sounded, though I will say that the unit was built to professional standards and operated without a glitch. I heard the DAC1 in a few different situations, in comparison to my Audio Note 3.1x as a stand-alone player, and with both the 3.1x as a transport and a CEC TL1 transport. Regrettably, I did not have any audiophile-grade digital cable, so I used a cheap digital cable from Radio Shack terminated with BNCs with the Audio Note, and with the Benchmark I used an RCA interconnect to the CEC. If that botches this review for you, so be it. That's what I had on hand, and I'm not sure the Benchmark boys and girls give much credence to audiophile cables anyway. Near the end of my time with the DAC1, I took delivery of new speakers, the Ensemble Figuras that I enjoyed so much last year. They are less full sounding than my previous reference speakers, the ATC SCM 35s, though they are more detailed and more refined.

Benchmark claims very high jitter reduction, which means that the transport should make no difference to the sound, but the transport did make a difference. I preferred the cleaner, sweeter, and more detailed presentation of the CEC'd Benchmark. My first impressions were of an amazingly transparent sound. Vocals were in the room, with no extra fat, no microphone feed, nothing, just voices. It was very exciting, and the imaging was stunningly precise and three-dimensional. It clearly embarrassed my Audio Note player on those fronts. The bass was also faster, tauter, and more detailed, although not as textured as the Audio Note's. The top end seemed more extended and detailed than my reference player's.

Out of the box, the Benchmark DAC1 was clearly a player that I would happily and easily recommend. Familiarity bred a deeper, less impressionistic appreciation. The sense of midrange transparency remained, as did the imaging and detailing. However, with the ATC speakers, what emerged over time was that the excellent transparency of the midrange was not matched by the transparency of the bass and treble. Fairly or unfairly, the disjunction of bass and treble from the midrange made the mids stand out as artificial rather than organically related to the frequency extremes.

The DAC1 is ruthlessly revealing. It's a just-the-facts-ma'am product and, at least for me, was not a conveyer of emotion. It delivered the news, for better or worse. Are you looking for a suave DAC? I wouldn't suggest the DAC1, but if you want to know what's on your CDs, the DAC1 should be on your list. Keep in mind that the $975 DAC1 was being compared to a $2895 all-in-one player, and against several other more expensive CD players, including Ensemble's Dirondo/Hi-DAC combination. The Ensemble combo's seamless integration made its transparency bracingly lifelike, but the Benchmark's frequency disjunction made it seem a little odd. The Benchmark DAC1 proved an excellent performer, but with shortcomings. At one-fifteenth the price of the Ensemble duo, I'd still recommend it for the right system. Ultimately I preferred the Audio Note 3.1x for its more integrated, organic sound. It also gave a better sense of the musical message. Though it fell short on the imaging front, the 3.1x simply sounds more like what I want.

With the Ensemble Figuras' leaner tonal balance and greater transparency, the DAC1 sounded a bit bright and grey. The sound was again more analytical than emotive. As with the ATCs, there was no grain or grit, but the DAC1 with the Figuras was a harder recommendation.

The Benchmark DAC1 is a great performer at its price point. Its midrange is close to the best I've heard, and its bass depth and treble extension are good, though not as transparent as the mids. That the DAC1's bass and treble don't match its midrange may not be important in systems with modest speakers and amplifiers. In such systems, the DAC1 will be the class president. Larry Cox 

DAC1
Retail: $975

Benchmark Media Systems
web address: www.benchmarkmedia.com