Media Server Reviews

Apple may not have been the first to market with a portable digital audio player, but its original iPod defined the genre: a device small enough to fit into a shirt pocket. When companies like Acoustic Research, Astell&Kern, Fiio, HiFiMan, and Questyle introduced portable players that could play high-resolution files, they echoed the iPod's form factor. The exception was the Toblerone-shaped PonoPlayer, but even that was small. The subject of this review is another exception: The DMP-Z1, from Sony's Signature Series, is comparatively enormous—almost the size and weight of a regular preamplifier. At $8500, it's also considerably more expensive than other players.

A Walkman?
The last high-resolution music player from Sony we reviewed was the HAP-Z1ES ($2000), which Kalman Rubinson wrote about favorably in May 2014; that player is intended to be used in a conventional system. The DMP-Z1 is described on Sony's website as a Walkman—though perhaps it's more of a SitInTheLimoMan. Either way, it's an elegant-looking piece of kit finished mostly in gloss black, with a color touchscreen in the center of its top panel.

Dominating the DMP-Z1's front panel is a large, mega-bling, gold-plated brass volume-control knob— a window in the top panel reveals even more of the knob. At the front edge of the top panel, between the volume control and the window, are three buttons: Track Backward, Play/Pause—this has a raised stud in the center so you can find it without looking—and Track Forward. To the Volume knob's right is another button; pressing and holding it for four seconds turns on the DMP-Z1. To the knob's left are two headphone outputs: conventional single-ended stereo on a 3.5mm jack, and balanced stereo on Sony's 0.17" Balanced-Standard jack. These can be set to Normal or High Gain (+6dB).

The rear panel has a USB-C port and a 19.5V DC jack for charging the DMP-Z1's internal battery. (The percentage of battery charge is shown at the top right of the touchscreen.) The player's 256GB of internal storage can be supplemented with two microSD cards, their mounting slots concealed under a hinged panel on the player's left side. When you connect the DMP-Z1 to a host computer with USB, the player asks if you want to turn on USB Mass Storage. Touching "OK" mounts the internal storage drive on your computer's screen. To copy music files to the DMPZ1, Sony recommends their Music Center for PC app, or drag'n'dropping content with Windows Explorer. Mac users can simply copy files using the Finder. When you turn off USB Mass Storage, the message "Creating Database" appears on the Sony's screen, followed by the player's Library screen.

Playing music
Other than the four physical buttons, everything is controlled with the DMP-Z1's touchscreen. The Library screen shows what music is stored on the player; the library can be sorted by "All Songs," "Album," "Artist," "Genre," "Release Year," "Composer," "Playlists," and "Hi-Res." This screen also allows the user to select the USB DAC and Bluetooth Receiver functions. When a song is playing, the screen in Standard mode shows the cover art and song info. Other modes are Spectrum Analyzer (octave bands plus a couple extra) and Analog Level Meter. The Library screen can be accessed when a song is playing by swiping down and exited by swiping up. Songs can be bookmarked or added to a playlist.

Inside the box
Following the DMP-Z1's premiere at the Hong Kong Advanced Audiovisual Exhibition in the summer of 2018, Rafe Arnott previewed it on our InnerFidelity website. According to Rafe, the DMP-Z1 uses a pair of Asahi Kasei Microdevices AK4497EQ DAC chips, a 32-bit part operating with PCM data at sample rates up to 768kHz, and DSD data sampled at up to 22.4MHz. The AK4497EQ features what AKM calls Velvet Sound technology, which appears to be high-current capability, and also offers six choices for the reconstruction filter, these operating with 32-bit precision. Sony labels these filters Sharp, Slow, Short Delay Sharp, Short Delay Slow, Super Slow, and Low Dispersion Short Delay. A filter is selected by pressing the toolbox icon in the bottom right of the touchscreen, then Output Settings and DAC Filtering Selection. When a different filter is chosen, the player mutes for a few seconds as the new filter coefficients are loaded, then resumes play.

The DMP-Z1 offers a variety of DSP functions: a 10-band graphic equalizer; bass, midrange, and treble tone controls; DSEE HX, which upsamples lossy-compressed and CD-definition data; DSD Remastering, which transcodes PCM data to 5.6MHz DSD; a Dynamic Normalizer, which minimizes loudness differences for different tracks; and a Vinyl Processor—this last said to produce "rich sound that is close to the playback from a vinyl record on a turntable." As well as a standard setting, Vinyl Processor can be customized with adjustments for surface noise, tonearm resonance, and turntable resonance. Purists like me can bypass all these options, other than DSD Remastering, by selecting "Direct Source (Direct)." For playback of DSD files there are two ultrasonic-rolloff filter options and gain settings of 0 and –3dB, the latter recommended to avoid clipping.

The headphone outputs use high-performance Texas Instruments TPA6120A2 chips, which I last saw in Music Hall's ph25.2 headphone amplifier, reviewed by Sam Tellig in May 2010. The internal wiring is all sourced from Kimber Kable.

Setup
I don't have headphones fitted with Sony's Balanced-Standard TRRS jack plug, so for my auditioning I used the 3.5mm stereo output jack. When you plug in a pair of headphones, the DMP-Z1 mutes and an orange light on its top panel illuminates. The player is unmuted by turning the Volume knob to its minimum position and back again, or by waiting a few seconds. I didn't need to use the player's High Gain mode with the low-impedance Audeze LCD-X and AudioQuest NightHawk headphones, though it did help with the high-impedance Sennheiser HD 650s.

As the Sony has two slots for microSD cards, I first tried to play familiar music files stored on two cards I'd been using with my PonoPlayer: a 16GB PNY and a 64GB SanDisk Ultra Plus. However, the DMP-Z1 couldn't find the files on these cards. When I looked at the manual to see what I was doing wrong, I found this: "Use a microSD card that has been formatted on the player. Sony does not guarantee the operation of other microSD cards." I reformatted the cards with the DMP-Z1—it uses the FAT32 file system—and recopied the music files to them from my laptop. Still no joy. Farther down the relevant page of the manual it says, "Sony does not guarantee the operation of all types of compatible microSD cards with the player." Perhaps that was the problem.

I unmounted the cards and began using both the music that had been included in the DMP-Z1's internal storage and files I copied to the DMP-Z1 from my Mac mini via USB. I also connected the Sony's USB port to a port on my Roon Nucleus+ server and selected "USB DAC" on the touchscreen. Roon 1.6 running on my iPad mini recognized the Sony as "Player (ALSA)," and once I'd enabled it as a playback zone, with DSD data transmitted as DoP, and defined the DMP-Z1 as an MQA decoder and/or renderer, I could stream music to it from the Nucleus's internal storage.