Benchmark Media Systems: DAC2 HGC D/A converter

The DAC2 HGC is a followup to the popular DAC1 [Tape Op #33]. It features more than 15 enhancements, so we were excited to use this unit. Benchmark Media Systems is a company that straddles the audiophile and recording markets. Consequently, the DAC2 HGC is designed to serve the needs of both industry segments. I won't cover all of the updates as some have minimal application in our workflow (e.g., remote control voltage).

Physically, the unit is a half-rack design, which I disdain, but location engineers love. Most people probably don't mind. Benchmark offers multiple racking options for curmudgeons like me. Included is a sturdy, metal, remote control, which can be useful, especially if you place your converter away from your gear - say, closer to your power amp. The review unit came with a detailed user manual, which is both appreciated and worth bonus points given the lack of attention some venders place in this area. Popular features from the DAC1, such as dual headphone jacks and front-panel gain knob, remain unchanged.

Most of the new features were requested by DAC1 users. These include visual indicators for sample-rate and word-length; additional analog outputs and digital and analog inputs; digital pass-through; native DSD conversion; polarity switch; asynchronous USB 2.0; and more. Inside, Benchmark made many electronic updates, including a noise lowering, distributed power regulation system.

A few things are brand-new technologies. Foremost in my mind is the DSP that promises 3.5 dB digital headroom beyond 0 dBFS. Those familiar with Nielsen and Lund's AES paper on 0 dBFS+ levels (and if you're not, you really should change that) know that the converted analog output can still clip on playback, even though the digital source material may never exceed 0 dBFS, because of inter-sample peaks in the reconstructed waveform. The DAC2 HGC maintains at least 3.5 dB of headroom throughout the conversion system, which precludes it from clipping. Additionally, conversion is handled by four balanced 32-bit chips. According to the company, the 4:1 redundancy lowers noise and distortion to industry leading levels. Home Theater Bypass is a mode that sets the pass-through gain to unity. This takes the gain control attenuator out of the equation completely, which is how most recording engineers use a DAC. Those wanting level control may opt to use the Hybrid Gain Control (HGC) system. This combines active and passive analog gain control with digital gain control. Source signals are controlled by the rotary volume knob, which may also be operated by the remote. Analog inputs are never converted to digital, and digital inputs never pass through an analog potentiometer. Digital inputs are precisely controlled in the 32-bit DSP system. These are only a few of the new features. Check out the manufacturer's website for a complete listing.

I plugged the unit via USB into my mastering PC and expected to be rolling. No dice. The good folks at Benchmark gave me some driver and configuration settings to try, but after a few hours, I was still getting static from the DAC2 HGC. For fun, I plugged the Benchmark into my Apple laptop. It worked immediately. I tried it on a Mac Mini, Mac Pro, and Mac G5. All recognized the converter instantly. I brought this up with PCAudioLabs, my workstation provider, and it is definitely a Windows "thing" with my version of Windows 7, and not a Benchmark "thing". Although PCAudioLabs offered to work with me until we got it running, I gave up on PC USB and used a digital connection.

DSD, an alternate to PCM digital, is a popular format among some mix engineers. Some people handle DSD by converting the data to PCM and work that way. But I wanted to test the new DSD streaming feature, so I connected the digital out of my DSD player to the Benchmark. The converter displayed sync, but would not produce audio. Now, there are two protocols that will bitstream DSD to DACs: ASIO, and DSD over PCM (DoP). Bitstreaming avoids a DSD to PCM conversion. I was not able to get my hardware to send data to the Benchmark all by itself. However, using JRiver Media Center, a respected full-resolution player, I was able to stream data from the DSD box through the Benchmark. I was also able to play DSD files sent to me via FTP. Sweet. If you have a DSD machine, replacing its converters with the Benchmark DAC2 HGC is a nice improvement.

I decided to throw the DAC2 HGC against my updated Crane Song HEDD 192 [Tape Op #26]. Full disclosure, I used to own a DAC1, but sold it because most times I preferred the Crane Song to the Benchmark. I never had a problem with the DAC1. I simply didn't use it. I was curious to see if the DAC2 HGC was simply a DAC1 with more lights. (Hint: it's not. It's that, plus even better sonic performance.)

But everyone is here to learn about the sound. What's the verdict? At first, I could hear no difference between the Crane Song and the Benchmark. Once they were level matched, it was a virtual tie. After getting used to the DAC2 HGC over different projects, I started to tell the two apart. From the low end to the mids, I think they are nearly identical, but from the high mids extending to the highest frequencies, the DAC2 HGC seems to put a halo around things. It is very subtle, with a wider, deeper, more-ness. In some ways, it's like adding 0.5 dB through a side of a mid/side processor, but that's not even the best description, because the detail in the middle is slightly enhanced as well. Over time, I found that the Crane Song was tighter and the Benchmark was wider. But I can't stress enough how refined the differences are. Mastering engineers, by nature, work at the limits of gear performance. We view D/A boxes as processors like an EQ or compressor, and will likely audition multiple A/Ds for playback. I predict brisk sales of the DAC2 to mastering shops. Most people will lump the new DAC2 HGC with the most respected converters from Apogee, Prism, and Lavry. The Benchmark is beyond good, residing in the realm of "refined preference." First World Problems, to be sure.

The original Benchmark DAC1 has been used to master many Grammy-winning and chart-topping records. It is hard to imagine that even better performance has been squeezed out of that box, but the DAC2 HGC does that. More than an updated faceplate on the original DAC1, the DAC2 HGC offers its own reference sound that will be welcome in the listening environments of both audio engineers and audiophiles. Personally, I would put the new Benchmark unit against any 2-channel D/A on the market. And did I mention it costs a fraction of what the converters it competes against do? ($1995 MSRP; www.benchmarkmedia.com)