One nit I have to pick with the xDSD: If there is no active source, the xDSD produced a low-level whine/hum that continued, unabated, until it locked onto an active source. Also, occasionally I noticed when going from an MQA track to a FLAC or DSD track the tune would begin with the first ½ second clipped off.
When compared to the ergonomics of a pair of Bluetooth-enabled earphones or a headphone connected directly to your smartphone with phone controls in its cabling, the primary disadvantage of the xDSD is that you can’t go smoothly from listening to music on your smartphone to answering phone calls with a touch of a button, as you can with these other two connection schemes.
As I said, the xDSD is remarkably unbiased in terms of favoring a certain pair of earphones or championing a particular sonic coloration. During my multiple listening sessions with many different headphones and sources, the most sonically prominent feature I noticed was the recording’s shortcomings rather than any issues created by the xDSD/headphone combination. In other words, the weakest sonic link in the source/xDSD/headphones system was the recorded source 99% of the time.
Compared with my current reference headphone amplifier, the Sony TA-ZH1ES ($2399), the xDSD’s output sounded similar with most headphones, but not identical. The Sony produced more bass energy than the xDSD with some earphones, such as the Earsonics EM-10 CIEM. While on a purely subjective pleasure level there is something special about listening to music through the Dennis Had-designed Dragon Inspire IHA-1, the xDSD delivered fuller, yet tighter and more incisive bass when connected to the HiFiMan HE1000 V2 headphones than the Dragon Inspire, especially on tracks with thick bass lines such Years & Years’ “Palo Santo.”
Speaking of bass, one feature on the xDSD that I did not find terribly useful was the X-Bass function. With the vast majority of headphones switching in the X-Bass didn’t seem to do much, if anything, to change bass response. When I switched on iFi’s 3D+ circuitry it did seem to s-t-r-e-t-c-h the soundstage wider, but the effect was also accompanied by a loss of image specificity and centerfill.
Compared to the sound directly from the headphone output of my iPhone SE, with the highly efficient Earsonics EM-9 universal in-ears, which the iPhones’ internal headphone amp had no problem driving to well past my max volume limit, the xDSD yielded a less brittle upper midrange, wider soundstage, and better image specificity on the same tracks. This was especially noticeable on the Tidal version of the Demi Lovato single “Sorry.”
I see two quite different “types” of audiophile as the primary customers for the xDSD. First, younger, more mobile-oriented audiophiles with smartphones and portable computers could find the xDSD to be the perfect “step-up” audio device to improve sound from all sources. Long-time audiophiles (the ones with the 25-year-old DACs that they still love for Red Book) could add an xDSD to their system as an auxiliary digital device that would give them access to all the newest high-resolution files, streams, and digital codecs for a pittance of the price they paid for their “main-squeeze” DAC. Both types of audiophile will be pleased and impressed by the xDSD’s flexibility, utility, performance level, and overall value. I know I was.
Specs & Pricing
Type: Portable/desktop DAC/headphone amplifier
Inputs: USB, coaxial SPDIF, TosLink, Bluetooth
Formats supported: PCM up to 768/24; DSD to DSD512
Output: Unbalanced, fixed and/or variable
Dimensions: 66.5 x 19 x 95mm
Weight: 127g (0.28 lbs.)