Astell & Kern AK70 mkII vs Sony NW-ZX300 – which is better?

When Sony released its first Walkman almost four decades ago, the world stood up and listened.

Not only did it stand up, it walked around and listened. It listened on the way to pick up milk, it listened through school lunchtimes and on long train trips. In fact, it listened just about anywhere it could.

For years that's how it was was, but if the era of carrying around tapes and CDs was a kind of zenith for Sony, a bite of a certain Apple at the beginning of the digital age has irrevocably changed the portable landscape.

With on-the-move listening having taken a further shift toward smartphones, even the latter isn’t dominating the world of portable music players any more.

In recent years, Astell & Kern has experienced most joy in this area of the hi-fi market, winning two of the three What Hi-Fi? Awards in the personal music player category in 2017, for example, but the Walkman is pressing hard to regain its place at the top table.

It makes sense, then, when Sony’s latest hi-res Walkman reaches our testing rooms, we pit it against our rather sterling Product of the Year, Astell & Kern’s AK70 mkII.


For its part, Sony describes this latest Walkman as being “technically superior in every way” - and there can be little argument over the NW-ZX300’s impressive spec sheet.

Powered by the company’s S-Master HX digital amp, which Sony claims reduces distortion and noise across a wide range of frequencies, this personal music player can handle PCM files up to 32bit/384kHz and 11.2MHz DSD native, with MQA files also catered for and its DSEE HX enhancement engine on hand to upscale more lowly files to “near hi-resolution quality”.

MORE: High-resolution audio – everything you need to know

In that respect, it’s superior to the A&K (which can handle files just as high in resolution but downscales to 24bit and lacks the Sony’s MQA handling). Where the AK70 mkII does have an advantage is with its ability to stream via Tidal.

Given that Tidal accounts for the bulk of hi-res listening at the moment, alongside the ubiquity of free wi-fi on the move, being able to stream is extremely advantageous.

Where the pair meet is in their expandable 64GB of memory, in their catering for regular, balanced and (via inbuilt Bluetooth) wireless headphones, and their optional usage as portable USB DACs.

MORE: MQA audio – What is it? How can you get it?


The A&K is both an update on and upgrade to the AK70 we so loved. There are small aesthetic variances in the mkII, including the textured pattern on the volume dial now being waves rather than speckles, but the most telling is its marginal increase in heft.

That’s down to the need to accommodate new internals. It is now a dual-DAC design; the company also claims amplification has been enhanced and jitter reduced; battery life has been upped. That’s a smart move, as we find streaming Tidal over wi-fi a particular drain - as well as causing the AK70 mkII to run slightly warm.

That aside, it’s a nigh-on perfect portable companion. We’d prefer slightly rounded edges to its strictly straight ones, but we’re glad to see the reappearance of the shimmery back panel and bright, high-contrast 3.3in touchscreen. And the more definite clicking of the volume dial is undeniably satisfying.

On pure looks, though, we’d probably take home the Sony.

There’s no need to hanker after rounder edges here, though the NW-ZX300’s smooth and rigid aluminium milled frame (of which we are immediate fans) is not here purely as eye candy: it’s designed to provide strong resistance to electrical noise for clearer, more stable sound.

It frames a highly responsive touch-screen, intuitively serving all of your playback needs except volume, which is altered via buttons on the Walkman’s right flank. That’s also where you’ll find the power button, additional play/pause and track-skipping controls, and a 'hold' switch.

So no tactile volume dial, but your thumbs should have little trouble locating the controls - and ergonomically, the Walkman wins out overall.

MORE: Best music streaming services 2018

With testing underway, there’s little to choose between user experiences. Both screens are pleasingly responsive – though we’re at a loss as to why the Sony’s doesn’t stretch to its full length – with folders well set out and easily navigated.

Our only real bugbear is with the Walkman’s maximum volume level. We test with a range of headphones, even the least sensitive of which struggle to really sing - even when the NW-ZX300 was pushed to its limits.

It was generally fine, but certainly something worth considering when matching. It's not an issue we come across with the A&K.

MORE: Best portable music players 2018


Sonically, the first thing anyone making this comparison will notice is the level of detail and clarity on offer from each.

Playing Neil Young’s Harvest, for example, there’s such great space and texture to instruments and vocal that it could serve as example as to why hi-res is beginning to command digital hi-fi.

Each strand is clearly audible, set out in space by both players’ clarity, yet at the same time knitted so well musically as to never become isolated.

It’s an incredible talent, one that is shared - though the Sony comes out marginally on top. Nonetheless, the AK70 mkII is a demonstrable improvement over its predecessor in this regard.

It’s something we’re used to Sony getting right, as is the fine balance this Walkman offers.

Strings of acoustic guitars are allowed to ring with great richness, with ample bass to tether those highest frequencies. A full-bodied middle affords even Young’s cuttingly thin vocal the warmth it needs to sound human.

This Sony is very much in the manner of the company’s previous personal music players, but that also brings with it some of the same shortfalls.

If the NW-ZX300 could match its clarity with equally opulent dynamic expression, it would be going toe-to-toe with A&K. But this is where it misses the mark.

MORE: Best iPod alternatives 2018

Specifically, it’s a lack of punch and excitement, and an overly light touch when it comes to the grandest dynamic shifts, that leaves us wanting more – but in the wrong way. Though it is not entirely flat, it demonstrates a timidity that leaves the AK70 mkII a whole star in front for the same money.

The latter has sharper teeth and grippier bite. It’s clear when we play one and then the other, but being overly shy is something that hampers the Sony even in isolation.

The A&K's better timing is more obvious via direct comparison – the NW-ZX300 is certainly not disorganised, just a tad looser than its rival. But that the AK70 mkII handles rhythm more adeptly is an unarguable truth.


Though A&K emerges victorious overall – that wealthier dynamic range compounded by tighter rhythmic sensibility and its offer of streaming via Tidal – putting the pair head-to-head demonstrates the Sony's preferable levels of outright detail and clarity, not to mention its greater array of file options.

Undoubtedly this is not the Walkman to restore Sony's command of the personal music players market, but ultimately it is very capable and will garner many an admirer. We've been saying this for a little while now: if it could give us just a little more punch and excitement, there’s a five-star review waiting.

For the time being, however, that honour belongs very much to Astell & Kern. The AK70 mkII remains the most talented personal music player on the market at this price.

Astell & Kern AK70 mkII


FOR: Brings sonic improvements over AK70; class-leading transparency; Tidal access; can perform DAC duties; nice design

AGAINST: No MQA support

VERDICT: Setting the bar for transparency at this price, the AK70 mkII is not far off portable perfection

Sony NW-ZX300


FOR: Great clarity and detail; wealth of file options, including MQA support; fine build and intuitive UI

AGAINST: Lacks punch and struggles with more extreme dynamic shifts; not the streaming support offered by class leader

VERDICT: It isn’t quite a return to Sony’s heyday, but the NW-ZX300 offers mightily impressive levels of clarity and detail for the price

What Hi-Fi?

What Hi-Fi?, founded in 1976, is the world's leading independent guide to buying and owning hi-fi and home entertainment products. Our comprehensive tests help you buy the very best for your money, with our advice sections giving you step-by-step information on how to get even more from your music and movies. Everything is tested by our dedicated team of in-house reviewers in our custom-built test rooms in London, Reading and Bath. Our coveted five-star rating and Awards are recognised all over the world as the ultimate seal of approval, so you can buy with absolute confidence.

Read more about how we test