Input: USB (24/96), Coax S/PDIF and Toslink (24/192), IEC inlet
Output: 1 pair RCA, 1 pair XLR, 1/8" headphone jack
Dimensions (W x D x H): 9.5" (black); 8.5" (silver) x 10" x 2"
Weight: 5 lbs (2.3kg)
Availability: online and through Authorized Dealers
Z Ultra-Compact Component
The Zdac hails from Parasound's Z-line of "ultra-compact components" that includes the Zamp V.3, Zphono, Zphono-USB, Zcd, Ztuner, Zpre2, Zbreeze cooling fan, and the Zselect five-pair speaker selector. The Z-line comes in silver or rack-mountable black and all of the Z components share the same chassis so one could have a complete matching Z-system (sans speakers). For some, matching components are a plus while for others, mainly for certain kinds of audiophiles, matching components take all of the fun out system mixing and matching. Thankfully you can have the Zdac either a la carte or prix fixe.
The Zdac can function as a 24/96-capable USB DAC, a 24/192-capable S/PDIF DAC, and a headphone amp. Handling the USB input in Isochronous Adaptive mode is the TI TAS1020B USB receiver and the Zdac re-clocks and upsamples all incoming data to 24-bit/422kHz via the Analog Devices AD1895 sample rate converter before handing off the upsampled signal to the Analog Devices AD1853 DAC. That Texas Instruments USB receiver only supports USB 1.1 which is one reason for the USB input's 24/96 limit and I'd imagine Parasound, and Holm Acoustics who helped design the Zdac, decided to go this route to provide a driverless plug and play USB device for all, even Windows users.
The back side of the Zdac is simple and straight forward with pairs of RCA and XLR outputs, and USB, Coax, and Toslink inputs and an IEC socket for connecting the included power cord. The front panel is equally simple with a push button on/off switch, volume control for the neighboring 1/8" headphone jack, input display, and the input selector knob. I reviewed the Zdac in USB mode using both the XLR and RCA outputs into my Pass Labs INT-30A. Connection was simple and all I had to do was point Pure Music to the Zdac and we were off to the races.
Adaptive-mode USB has become a sort of pariah these days with the flourishing of asynchronous USB DACs. And for good reason, seeing as asynchronous mode USB allows the DAC to control the all important flow of data with its own internal clock whereas with adaptive USB the DAC is at the mercy of the computer. As such, and in theory, adaptive mode USB is more prone to system-induced jitter. In practice can be another matter and listening to the Parasound Zdac did not offer any sonic hints as to its USB persuasion. I found the Zdac to be one heckofa-fun DAC to play music through and I must admit to being somewhat surprised by how much enjoyment it offered.
After all, it had two strikes going in, adaptive USB and that 24/96 limit for USB, but listening to all manner of music proved engrossing and involving. The Zdac offers a muscular and concise-sounding presentation with a very nice amount of attention paid to pace and edge without being edgy. Bass response is on the tight but full side, there's plenty of dynamic snap, and tone colors are painted with a fairly broad brush although I've heard deeper, richer presentations. Again think concise and resolute with a very clear sense of attack and edge. A real toe tapper.
While there's a pleasant amount of air in and around instruments, the overall sound picture is somewhat foreshortened, a tad cramped. This becomes apparent with complex music where the sense of place is denser and more compact than I've heard from other DACs. Oddly, I believe this helps with the Zdac's sense of drive so a potential minus can be a plus for certain listeners. Again if music with a driving beat spends a lot of time playing through your system, you may very well enjoy the Zdacs firm grip on musical movement. With vocals I noticed a slight lean toward the sibilant with less of the singer's body on display. But overall, the Zdac was plain fun to listen to regardless of the music's pedigree.
So CD-quality was served up in a musically satisfying manner as were higher resolutions. Of course the 24/96 limit meant that higher sample rates were first downsampled but they were still fine-sounding although Zdac owners would have no reason to buy files greater than 24/96. The headphone output drove my Audio Technica ATH-W1000s without a problem but I would say this combo leaned toward the lean, dry-sounding side of things. The headphone output impedance is rated at 40 ohms so ideally you'll want to mate the Zdac with high impedance 'phones.
[Note: Parasound has since modified the headphone output impedance of the Zdac to 10 ohms. This change will be included in the second production batch which is just going out to dealers - 3.21.2013. Ed.]
Because of its small form factor, the Zdac can live comfortably on a desktop including mine. Connected to my ADAM A3xs with Kimber Kable Select KS 1126 Balanced ICs, the pair offered up a pulse-pounding display of sonic fireworks. Big, bad (in a good way), and ballsy.
The Parasound Zdac took me by surprise as I wasn't expecting to enjoy it nearly as much as I did. If you can live with its 24/96 limit for the USB input and high output impedance for headphones, the Zdac offers up a tightly knit musical package that can get you up and out of your listening seat, moved by the music.
Also on hand and in use during the Parasound Zdac review: Mytek Stereo 192-DSD DAC, Teac UD-501, Emotiva XDA-2 Differential Reference DAC, Metrum Hex