Audio Research DAC 9 Review

The sound of Minneapolis can't be nailed down to anyone or anything specific, but if I had to select an artist and equipment on which to play this artist, I would likely select Prince and components from Audio Research Corporation. Prince and Audio Research provide the quintessential sound of Minneapolis. Both are originals, both have large well-deserved fan bases earned over decades, and both are at the top of their industries. Prince and the ARC is one band name that we'll never get to see officially replace the NPG, but those of us lucky enough can listen to Prince & ARC in our homes seven nights a week. 

Over the last several weeks, I've combined Prince's amazing music with the Audio Research DAC 9 on many occasions. The results have been fabulous. Listening to Prince's song Avalanche from his One Nite Alone album, one can really get a sense for his talent. This track is far from overproduced with an R128 dynamic range score of 10 / 9.6 LU. The track features Prince and his piano, that's it. Through the Audio Research DAC 9, the opening notes of his piano ebb and flow from mellow taps to sudden strikes of the keys. The transients in these strikes are reproduced wonderfully in that they help each abrupt note serve up the rest of the rolling melodic beauty on a platter. 

Listening to the remaining four minutes of Avalanche, Prince's main and backing vocals have an incredibly natural, raw, and unaltered sound through the DAC 9. Even if one disagrees with Prince's politicized lyrics, it's nearly impossible to not feel the emotion and conviction in his voice. Had the DAC 9 imparted an overbearing sonic signature on this track, much of the emotion would've been lost. The ARC DAC 9 provides Prince and his piano a chance to naturally aspirate and appears to be right in its wheelhouse reproducing the acoustic artistry of this Minneapolis treasure. 

DAC 9 Details

I certainly can't be accused of burying the lede in this review or stringing readers along like Allen Collins and Gary Rossington during the four minute guitar solo in Free Bird (link), but I should dig a bit deeper into what makes the DAC 9 tick.

The Audio Research DAC 9 is a major step up from the DAC 7 and a solid step up from its predecessor the DAC 8. Whereas the DAC 8 was a purely solid state design, the DAC 9 has an advanced tube output stage with solid state regulation. This analog design was taken from elements of the ARC LS27 and LS28. This design stops short of what's available in flagship products such as the REF 6 preamp and Reference DAC, both with analog volume controls.

Digitally the DAC 9 evolved from the ARC GSi75 integrated. Audio research engineers started with the GSi75 digital platform, and advanced it significantly. Of note, is one piece of technology that will frustrate some people and excite others. 

There is a digital chip in the DAC 9 that is being used for purposes other than its intended design. This chip is not available in any other ARC DAC. Squeezing information about this chip from the Audio Research team is tougher than finding highly classified information online. This is the frustrating part for many people. As consumers we are just supposed to believe ARC and rely on the fact the company has a very stellar reputation. Fortunately, we can check their work in a different way, by listening to the final product. 

Secret design or not, if the DAC 9 sounds good, then most people will be excited about the product. Some control freaks won't rest, or even trust themselves that they like the sound, until this secret is unmasked. Oh well, keep waiting while everyone else enjoys thousands of hours worth of great music.

Before detailing some of the better features of the DAC 9's digital side, I must mention my biggest issue with this product. The USB interface used in the DAC 9 is less than great. It's the only part of this DAC that's not first class. The current DAC 9 USB interface is manufactured by Switzerland's RigiSystems. In and of itself this interface isn't all that bad, but in practice there are some serious issues. 

Most important to many computer audiophiles will be RigiSystems' lack of Linux support. Several years ago this wasn't really an issue because "nobody" used Linux computers for audio playback. Now however, many people are using Linux based products from Aurender, Auralic, Sonore, SOtM, etc... None of these devices work with the RigiSystems USB interface used in the DAC 9. I tried to get Sonore to support the DAC 9 on its microRendu, but without serious assistance from RigiSystems, it just won't happen. 

The USB interface also has some issues with Apple computers. In the recent past, after an OS update, Apple computers running OS X / macOS lost the ability to send audio to the DAC 9 at sample rates higher than 192 kHz. In addition to this current sample rate limitation, the DAC 9 is also limited to PCM playback when connected to a Mac. The DAC 9 uses macOS built-in Class 2 USB drivers, thus it has to accept DSD over PCM (DoP). Therein lies the issue. The RigiSystems USB chip doesn't use a version of DoP that works with Macs. 

I have a positive feeling about the long-term outlook for the DAC 9 and its USB interface. Audio Research has committed to a solution by the end of 2017. I'm unsure if this will involve a firmware update, software update, or hardware update. 

Some additional nuggets of information I picked up from my discussions with Audio Research are that the USB interface in the DAC 9 is internally powered. The DAC 9 doesn't accept power over the 5V VBUS wire in USB cables. The DAC doesn't feature galvanic isolation on the USB input, but this power configuration may serve to partially nullify this need. 

With respect to MQA, the DAC 9 doesn't currently support this technology, but Audio Research may provide an MQA upgrade in the future for the DAC. Any MQA upgrade for the DAC 9 would require an internal hardware change.

Briefly touching on some of the specs, the DAC 9 features two distinct digital audio paths, one for DSD and one for PCM. The DAC has two TCXO crystal master oscillators from Integrated Device Technology, one for 44.1 kHz base sample rates and the other for 48 kHz base sample rates. 

The DAC 9 has quad D to A converters onboard. Both the left and right channels use dual stereo DACs in a mono configuration. This is supposed to increase dynamic range, currently at 114 dB (AES17), and reduce the noise floor. 

Two other features that are user selectable are native rate upsampling and digital filters. The DAC 9's upsampling can be enabled for all PCM content. It will upsample this content to either 352.8 kHz or 384 kHz, depending on the base sample rate of the original music (44.1 or 48). The digital filter can be toggled between a fast or slow roll-off, directly from the remote control for easy user A/B'ing. Upsampling can also be enabled/disabled via the remote, with only a short one second pause in playback. 

Listening Through The DAC 9

I listened through the Audio Research DAC 9 with most of the same components that are in my system for all reviews. The TAD CR1 loudspeakers, Constellation Audio Inspiration Mono amps, and preamp, and Wire World cabling are all stalwarts of my system. One addition to the system was the dCS Network Bridge. I used the Bridge as an Ethernet to AES/EBU converter that sent audio signals to the AES input of the DAC 9. Given that the DAC 9 has no volume control, a preamplifier was required. 

Last weekend the Rock and Roll Hall of Fame inducted my favorite band, Pearl Jam. Given this, what kind of PJ fan would I be without one of its songs in the review? I dug deep for this one and it payed off. 

In 2004 ten members of the Walmer High School choir from Port Elizabeth, South Africa traveled to Seattle, Washington. During their stay, the choir recorded an album with Pearl Jam's Eddie vedder. The album is titled the Molo Sessions and it contains three Pearl Jam tracks. It's not a traditional audiophile recording, but it has a dynamic range score of 15 and the music beats out any Diana Krall piece of "muzak" any day of the week. 

My favorite track on the Molo Sessions is Betterman. Right from the opening chord of Eddie Vedder's acoustic guitar, the track sounds naked. I don't notice any DAC 9 flavor covering the music. The guitar sounds very natural as Eddie's fingers can be heard sliding back and forth over the frets and across the strings. Unedited and untouched describe the sound really well. 

The best part of the track is at the 2:42 mark, when the South African kids chime in singing the chorus. Through their thick accents, they sound like ten real kids singing in the room as they repeat:

She loved him, yeah, she don't want to leave this way
She feeds him, yeah, that's why she'll be back again
Can't find a better man

Of course they are real kids, but on so many recordings and through products with much less fidelity, real kids may not sound like real kids in one's room. There can be an artificial distance placed between the artist and the listener. Not so with this non-audiophile recording through the Audio Research DAC 9. Great stuff. 

Moving to a bit more complex material, I tapped play on a favorite of mine, Michael Stern conducting the Kansas City Symphony in Britten's Orchestra. This is an out of print recording by Keith Johnson and Reference Recordings. Due to the agreement with the Symphony's union, RR can't sell any additional copies of this album. 

Track nine, Passacaglia, is always fun and a good system test. As the music starts from a barely audible creep, the strings are very sweet sounding. One can almost smell the wood of the instruments, if the listening room lights and one's mind are turned off. As the horns slip in, they have great definition even at very low volume levels. This is always the mark of a good DAC. 

One area where the DAC 9 falls short of reference DACs may be with full scale symphonic transients. Around 5:00 minute mark of Passacaglia things start to heat up with major string, horn, cymbal, and drum action. 45 seconds later when everything comes together in a big bang, the DAC 9 sounds a little slow or perhaps less fantastic on the transients than it was with simpler music. I don't sense any shift in tone of the instruments or compression of the dynamic range, just a bit of rounding of the edges where I've previously heard them as razor sharp. If anything, this may make the case for the Audio Research Reference DAC, if one is very focused on music of this ilk. 

Before finishing up with another song from Prince, it's worth mentioning another sonic characteristic of the DAC 9. Keeping in mind that all components impart a sonic characteristic on the music, I can best explain this with a visual photography analogy. Whereas some DACs can be like glossy photos / reproductions, the ARC DAC 9 leans toward a matte finish. It's not a dull DAC, just right of center on the glossy - matte continuum. This sonic signature can be heard through Nat King Cole's music on the album The Very Thought of You (Analogue Productions remaster). 

On both the opening title track and But Beautiful, Nat's vocal can be gloriously glossy. The glossy effect of smoking KOOL menthol cigarettes right before entering the recording booth, was something Nat thought he needed to perform. Right or wrong, the gloss can and should be heard. That said, without being at the recording the first week of May, 1958, I have no idea if the recording should be as glossy as I am used to hearing it or if the DAC 9 presents a more accurate picture. Like all things in this wonderful hobby, it comes down to taste and preference.

Getting back to the Minneapolis magic that is Prince and Audio Research, I must also go back to the One Nite Alone album. Those unfamiliar with Prince's true artistry and musical genius, must find a copy of this album. One Nite Alone ... Solo Piano and Voice by Prince is the official title. This isn't the three disc live set from his 2002 One Nite Alone tour, it's an NPG Music Club limited release album never sold in stores. On the album, Prince's talent can be heard without any trouble or the wading through of overly sexual lyrics and a massive band. 

As only Prince can do, he delivers a cover of Joni Mitchell's A Case of You by skipping the first three verses and starting with "I am a lonely painter, I live in a box of paints." The backing music on this track is nothing to write reviews about, but I love Prince's elegant vocal performance on this one. The DAC 9 reproduces his high, low, loud, and soft vocal swings wonderfully. His voice sounds very smooth in both the highest and lowest registers. This is a tribute to his vocal ability and the DAC 9's ability to let this through without imparting too much warmth or enhancing the edges with unnatural noise. In typical Minneapolis fashion both Prince and the DAC 9 are, for the most part, understated and comfortable away from anything that causes the spotlight to shine in their direction on this track.

Conclusion

The quintessential sound of Minneapolis is an apropos description of Audio Research, the company that trademarked High Definition in 1977. Its DAC 9 digital to analog converter is the best DAC ARC has released to date, short of its reference series. The DAC 7 and DAC 8 have both been eclipsed by design, technology, and sound quality. In my extensive listening sessions with the DAC 9, I heard unaltered, raw, and natural sound on some of my favorite recordings. This DAC will of course reproduce audiophile standards and performances captured by Reference Recordings, but the most enjoyable experiences I had while listening through the DAC 9 were with standard definition, "regular" music. I frequently listened through the DAC 9 while sitting at my computer working all day and while sitting in my listening chair in front of two loudspeakers. Either way, listening fatigue didn't even enter my mind. The only thing I wanted from my system during the Audio Research DAC 9's residency, was more music. 

Product Information:

• Product - Audio Research DAC 9 ($7,500)
• Product Page - Link
• User Manual - Link

Where To Buy (CA Supporter):

Associated Music:

• Computer Audiophile 100 Playlist
• Computer Audiophile PJ4CA Playlist

Associated Equipment:

• Source: Roon
• DAC: Berkeley Audio Design Alpha DAC Series 2
• D-to-D Converter: dCS Network Bridge
• Amplifiers: Constellation Audio Mono 1.0 / Monoblock Power Amplifiers
• Preamplifier: Constellation Audio PreAmp 1.0
• Loudspeakers: TAD Labs CR1 Compact Reference
• Remote Control Software: Roon Remote
• Remote Control Hardware: iPad Air 2
• Playback Software: Roon
• Network Attached Storage (NAS): Synology DS1812+, CAPS v4 Cortes Server
• Audio Cables: Wire World Platinum Eclipse 7 Interconnects (XLR & RCA), Wire World Platinum Eclipse 7 Speaker Cables, Wire World Platinum Starlight 7 Digital Cables,
• USB Cables: Wire World Platinum Starlight 7 USB 2.0, AudioQuest Diamond USB 2.0, Nordost Purple Flare USB 2.0
• Power Cables: ALO Audio AC6 Power Cables
• Ethernet Cables: AudioQuest Vodka Ethernet Cables throughout system
• Network: Cisco SG200-26 Switch, Baaske MI-1005 Ethernet Isolator, Apple AirPort Extreme, Calix 716GE-I Optical Network Terminal, ZyXEL C1100Z modem / router, CenturyLink 1 Gbps download / upload