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Wednesday, April 15, 2015

Audiophile Review!
Parasound zdac v.2
Stereo D/A Converter

Parasound zdac v.2 DAC
"Upgraded Headphone Amp Enhances The New Zdac"

Price: $549 retail
Likes: more HP oomph, first-rate build
Dislikes: give us 24/192 via USB please
Wow Factor: still way above its price

by John Gatski
 In 2013, I reviewed the Parasound zdac, a great value/performance 24/192 D/A that fit into numerous audio listening niches, including audiophile, home recording, and for use as a computer DAC (to 24/96). Never one to rest on its success, Parasound has made some key upgrades to the zdac, and made it better.
  Priced at $549, the zdac v.2 now offers front-panel quarter-inch and eight-inch headphone jack, separate line out and HP volume controls, digital audio connection to Lighting jack-equipped Apple devices (USB adapter required), increased headphone amp gain, fixed/variable line out switch and 12V input/output triggers.

  The new zdac maintains its solid feature set of USB, Coax/TOSlink SPDIF digital inputs, plus XLR balanced and unbalanced analog RCA line outputs. The most audible improvements are increased headphone gain and the fixed variable line out switch for those who want a fixed level for routing the output audio to other preamps.
  The zdac v.2 maintains its computer compatibility with USB input, though it is still limited to 24/96 using the USB 1.0 protocol, which requires no computer/device drivers. However, most DACs use the USB 2.0 protocol, which requires specific drivers, but allow up to 24/192 and higher sample rates. Today, most DACs, even inexpensive ones, can decode up to 24/192 and higher sample rate audio; some as high as 24/384. I would like to see Parasound add sample rate decoding to at least 192 via USB to remain competitive. With the increase use of computers as primary hi-fi players, a DAC needs that high-sample rate compatibility.
  Nonetheless, you can still play 24/192 via the optical input from a Mac computer to a zdac v.2. On 2013 and newer Macbook Pro Retina laptops, the  Mac's optical digital audio output maximum sample rate has been increased from 96 kHz to 192 kHz, which means the zdac v.2 (and many other DACs) will natively play 192 kHz audio hi-res from those Macs  Older Intel Macs have the ability to play out to 96 kHz only. Those computers take the 24/192 and downsample to 96 kHz, which means the zdac v.2 can still play music from 192 kHz sources.

Plenty of connectivity, including balanced XLR out

  The zdac v.2 maintains its excellent sound quality by using the Analog Devices AD1853 24-bit/192 kHz digital-to-analog converter chip, the same chip used in the Benchmark DAC1 series. All digital input signals are re-clocked and up-sampled to 422 kHz for improved sonics and improved jitter reduction. The Analog Devices AD1895 sample rate converter chip is used for the up conversion.
  The zdac's high-current headphone amp is claimed to drive virtually any headphones from 32 to 600 ohms. Unlike many low-cost DACs, the zdac v.2 is designed with a high-quality, toroidal transformer in its power supply circuit, ensuring plenty of voltage and current to drive most any headphone and line devices. The zdac v.2 factory specs are quite good with a 110-dB signal-to-noise ratio, and low distortion throughout the audio band at the various sample rates. The analog outputs, via unbalanced or balanced, have plenty of oomph — with 2.1 volts and 4.2 volts respectively.
  The half-rack zdac form factor makes it easy to install in a rack or to carry around in your bag for use as a stereo-recording monitor DAC wherever you go. The unit weighs about 5 pounds. It is available in silver or black finish.

The setup
  As with most DACs that I test (and I test a lot of them), a DAC needs a good listen to establish a sonic benchmark. I linked the zdac v.2 to an Oppo BDP-95 via SPDIF. For comparison, I had the original zdac, a Benchmark DAC2-D, and Mytek Stereo 192-DSD: much more expensive DACs, though with the similar form factor. I also listened to a couple of DACs closer to the price range of the zdac v.2: the  USB-connected Korg DS-DAC-100M ($350) and the USB/SPDIF Resonessence Concero-HP ($849); these two DACs do not have near the connectivity features and advanced analog circuit of the zdcac v.2  but do have good audio quality and compatibility with higher sample rate PCM and DSD.
  I know there are lower-cost DACs out there, but when you compare the build quality and parts selection and its well-above-its-price-range sound, the Parasound zdac v.2 is a steal at $549.

  For headphone amp comparisons, I listened to audio via the onboard headphone amps. For additional comparisons, I also routed the Parasound’s analog output to a Bryston BHA-1 HP amp/line out as well as to the analog input of the Oppo HA-1 HP Amp/DAC.
  Headphones included AKG K702 Anniversary, Shure SRH1840, Oppo PM-1 planar magnetic and Sony MDR-7510 headphones. Wireworld digital cables were used throughout the system. Essential Sound Products Essence II Reference power cords connected the components to the AC.
  I also integrated the zdac v.2 into my high-end playback system, consisting of, at the time, Pass Labs XP-10 preamp, Pass Labs XS-150 mono block, Class A amplifiers and my MartinLogan Montis speakers.

The audition
  When I reviewed the original zdac in 2013, I raved about its sound quality, considering the price. In fact, when I took it to the Capital AudioFest that year and put it in our stack of DACs A-B listening sessions, most people were hard pressed to differentiate it from other DACs, including the more expensive ones, in the demo.
  For the most part, the zdac v.2 is sonically identical to the original, but with increased headphone amp gain. In fact, i did not need to turn the volume control knob nearly as far with the low-impedance AKG headphones as I did the original zdac.
  During my testing, I played dozens of hi-res tracks from different genres, including Classical, Jazz and Pop. As with the original zdac, the zdac v.2 is a detailed, revealing DAC that performs considerably above its price point. I have always liked the analytical character of the Analog Devices DAC chip (Benchmark used it in its DAC1 Series), and the zdac v.2 gives me that quality in spades. Tight bass, a generous soundstage and crisp transient response on such instruments as cymbals and piano will please those who appreciate honest digital audio decoding.

Smart devices play just fine with zdac v.2

  When playing a DSD-to-PCM dub of the Warren Bernhardt So Real SACD — from the Oppo BDP-95 and monitoring via the AKG K702 headphones — the detailed presentation of drum cymbals piano and bass was well spaced. The kick drum was nice and tight. The line-output lets out more image and width when paired up with the gorgeous-sounding MartinLogan Montis electrostatics and the pair of $60,000 Pass XS150 amps that I recently reviewed.
  When comparing the zdac v.2 to the ESS Sabre chip units Benchmark DAC2-D, Mytek Stereo 192-DSD and Resonessence ConceroHP, the zdac's tight, tightly focused signature was more apparent in headphone amp A/B comparisons. The Benchmark and Mytek had more warmth to the mid and bass frequencies, and  a bit more space around the instruments, but again, I liked the analytical persona of the Parasound.
  When comparing the DACs through speaker listening, their sonic personas are harder to differentiate. They all sounded good. Picky headphone listening can spot the audio variables between these DACs, but a room often swallows up those differences. The zdac v.2 is definitely a competitive D/A.

Mobile-source audio
  With the 24/96 ceiling on zdac v.2's USB input, I carefully selected 96K download music to play from a Dell Venue 8 tablet via USB Audio Player Pro software. I linked the two via Wireworld Starlight USB cable, the software player recognized the DAC, and I commenced playing a variety of tunes.
  The first cut I played was "Tangerine," from the 24/96-remastered, hi-res Led Zeppelin III. The remaster has much greater separation and space between the instruments, which includes acoustic guitar and pedal steel guitar, mixed into a widely spaced stereo image. Through the headphones, the zdac v.2 projected the gracious instrument spacing of the mix, and its cool, quick transient character enhanced the detail. The line out into the amp/speaker system was even more immersive through the ML electrostatics.
  When playing a DSD-to-PCM dub of Warren Bernhardt’s So Real SACD — from the Oppo BDP-95 and monitoring via the AKG 702 headphones — the detailed presentation of drum cymbals piano and bass was well spaced. Kick drum was nice and tight. The line-output lets out more image and width when paired up with the gorgeous-sounding MartinLogan Montis electrostatics and the pair of $60,000 Pass XS150 amps

  On my PCM 24/96 dub of the Mercury Living Presence BachThe Complete Cello Suites by Janos Starker SACD, I really liked how well the organic tone of Mr. Starker’s cello — with the complex string harmonics, subtle room reverb —played through the zdac v.2. It may only be $549, but this is a really good DAC.
  As with the original zdac, the zdac v.2 is a smart choice to add new life to your old CD player or a cheap DVD player. I used the zdac v.2 as a high quality DAC/headphone amp for a RCA portable Blu-ray player with built-in 9-inch LCD that I took to my beach house. Playing through a connected HDMI de-embedder, I played CDs, 24/96 hi-res downloads and BD stereo soundtracks using a pair of Oppo PM-1 planar headphones. With the zdac v.2 this little A/V system kicked butt. I even watched The Who - Live at the Isle of Wight 1970 Concert Blue-ray, with the linear PCM stereo soundtrack blasting through the headphones.

A workstation D/A
  For those who have home recording suites (even pros), the zdcac v.2 can be smartly placed next to your editing computer or source deck, and used for monitoring your mixdown or direct stereo recordings. It would be better if it did 24/192 as well, but if you do CD quality or the more typical 24/96, the zdac v.2 works just fine. And as mentioned, it does decodes 24/192 from a Mac through the computer's optical output on the newest Macbook Pros, and outputs the 192  kHz audio at 96 kHz from older Intel Macs.

Per usual, Parasound uses good design and parts selection

  I pressed the zdac v.2 into duty for editing a Gibson jazz guitar track I was working on using a Macbook Pro and the Apple Logic recording/editing program. Via the Shure SRH-1840 open headphones during playback, I could clearly hear deep into the track, with the guitar’s pick attack and smooth Fender Deluxe Reverb harmonics, without any additional grit coming from the DAC. At twice the price, you will not do any better.

The verdict
  As with the original, Parasound zdac  I had few complaints about the zdac v.2, it has true hi-sound quality, the headphone gain gets a boost, we now have separate volume controls for line and headphone, and the a fixed/variable line-out circuit adds to its flexibility. It only lacks the ability to natively play 24/192 music via the USB, though you can play 24/192 via Mac using the optical jack. I know there are lower-cost DACS out there, but when you compare the build quality, parts selection and its "well above its price range" sound, the Parasound zdac v.2 is a steal at $549. A Stellar Sound Award for a stellar DAC.

John Gatski has been evaluating consumer, audiophile, home cinema and professional audio gear since 1992. In 1995, he created Pro Audio Review, and he has written for Audio, Laserviews, Enjoy The Music,The Audiophile Voice and High Performance Review. Everything Audio Network is based in Kensington, MDArticles on this site are the copyright of the ©Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited. He can be reached via

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