Disclaimer: Sony lent me their best headphone, their best DAP, and their latest DAC for evaluation. All of it goes back Sunday.
RMAA: Sony NW-ZX2 24-bit
RMAA: GloveAudio A1 24-bit
RMAA: MST Audio Chord Mojo-Kai (balanced) 24-bit
RMAA: Onkyo DP-S1 rubato 24-bit
RMAA: Astell & Kern AK70 Kai (Ryuzoh mod) 24-bit
RMAA: iPhone SE 24-bit
RMAA: Apple iPhone 7 24-bit
RMAA: Apple iPhone 6 24-bit
RMAA: Chord Mojo 24-bit
RMAA: Onkyo DP-X1 24-bit single-ended and balanced
RMAA: MS-AK100 24-bit new
RMAA: Astell&Kern AK380 24-bit
Outside it's gold, inside it's a mix. On high gain, the NW-WM1Z's single-ended out measures better than an iPod nano 7G, but not by much. And, it doesn't appear to get much louder than an iPhone 6. On high gain and in balanced mode, it owns the nano, sounding crisper and clearer. Either out is the sort of sound that goes really well with JVC's HA-FW02 and Astell & Kern's AKT8iE MKII and less well with mid-bright earphones like the Grado GR8/e and Beyerdynamic Xelento.
It works well, gets more than 10 hours of playback, is built like a tank, and while it's almost as heavy as a Leica, its weight and bulk feel good in the hand. But not in the pocket. The NW-WM1Z pulls down your trousers, strains your belt, and gets warm against your hip. (And maybe that' what you want; I'm not here to judge you.)
I'm here to judge the Sony. And to be honest, while it sounds good, it's another in a growing line of high-resolution players that only barely bursts the non-dithered 16-bit ceiling, viz., it's not high-resolution in anything but its ability to play 24-bit files. What it does is hold current under load better than most high-end players, suffering imperceptible from unloaded scores. The other thing it does - which it absolutely should not - is hiss. It's a bit less hissy than a 1st-gen AK100, but that player is from 2013, and cost something like 600$. The NW-WM1Z is 3200$.
It's got nice buttons though, and its sound signature is peachy.
Source: Premium Hi-Res Portable Audio Player | NW-WM1Z | Sony US
ADC: Lynx Studio HILO LT-TB
Computer: 2012 27" iMac
Cables: 1,5m Hosa Pro 3,5mm stereo to dual 3-pin XLR (around 8$); bespoke y-split 2,5 TRRS to dual 3-pin XLR made by Musashi Sound Technology.
NOTE: RMAA shows a volume setting of 100. That is an input mistake on my part. The volume was set to 120 or 100% of the NW-WM1Z's volume scale.
NL - no load
SM2 - Earsonics SM2
ES7 - Audio Technica ES7
DT880 - Beyerdynamic DT880/600
24-bit single ended @+0dB
24-bit single ended @+0dB summary
24-bit balanced @+6dB
24-bit balanced @+6dB summary
I expected better for 3200$. I'd have expected better from a 350$ audiophile DAP. Sony nailed design and the interface is nice, smooth, and the screen is decent for a DAP (though nowhere near the quality of a smartphone, though). But it's not a hi-res player.