Introduction

When you see the words Astell&Kern, or even head over to the company website, you are likely thinking it is a western brand, and perhaps even a fancy luxurious one at that. If so, then the re-branding exercise from its parent company Dreamus, which itself was previously known as ReignCom, has worked well. Astell&Kern, often simply referred to as A&K, is a South Korean brand that was established in 2013 and is most known for its line of digital audio players (DAPs), as well as making the 2.5 mm TRRS balanced connectors popular. Over the years, it has also worked with other audio brands to bring out headphones and earphones as collaborations under the A&K name, of which none could truly be called its own—until now, anyway.


Today, we are taking a closer look at the AK ZERO1, which A&K claims to be its first set of IEMs that hasn't involved another major brand in the R&D. The AK ZERO1 is a tribrid set using three different types of drivers, which is a bold choice for a brand not generally associated with earphones. But a single look at them shows there is plenty to talk about, including the unique aesthetics and use of what A&K calls a micro-rectangular planar driver that is quite unlike anything else I have seen before. The AK ZERO1 is hand-crafted in Japan and aims to be a new start for the brand when it comes to reinvigorating the world of IEMs, so let's see how these bold words hold up in our review which begins with a look at the product specifications in the table below. Thanks again to Astell&Kern for arranging a review sample for TechPowerUp!

Specifications

Packaging and Accessories

A&K may be a premium brand in the world of personal audio, but the AK ZERO1 aims to be a new starting point for its IEMs. As such, and because this happens to be my first experience with the brand, I had no idea what to expect for the unboxing section. The product box for the AK ZERO1 is about average in size and comes sealed in plastic. Remove the plastic and we are greeted by a predominantly black box with the company logo and product name, which is where I realized the product name is just ZERO1; however everywhere else, it is still referred to as the AK ZERO1 anyway! There is a render of the IEMs on the front too, with another on the back showing the composition and internal layout in more detail. Salient marketing features and specifications, including more information about the drivers themselves, are found on the back and sides, where "Made in Japan" is no doubt interesting from a Korean brand that calls this product wholly its own.


A&K is using a two-piece packaging with the inner box easily sliding off the outer sleeve from either the top or bottom. This inner box is simpler in design with the A&K logo in a darker black on the front of a lighter black base, and opens up from the side akin to a book. A pocket on the inner side of the lid contains relevant paperwork, and a thick piece of machined foam with precise cutouts snugly holds the IEMs in place on the other side.


We find a warranty guide and handy multi-language instruction book in the aforementioned pocket (online copies should eventually show up here). The instruction book is worth glancing through, especially if you are new to the world of IEMs; that said, head back to the other side and lift up the cardboard cover under the IEMs to find the cable that comes pre-attached out of the box. The other accessories are placed in a separate layer underneath, with the case and ear tips in their own individual compartments.


A&K shares very little information about the carry/storage case included with the AK ZERO1, although it does look and feel nice in person. It's predominantly black, including on the stitching of what might well be genuine leather or a very good imitation, and adopts a cylindrical puck shape for all but a straight cut at the back where the internal hinge connects the top and bottom pieces. The A&K logo is embossed on the top, and the case is soft on the outside and inside alike, with plenty of room for the IEMs with the cable to fit internally—you will just have to coil the cable in smaller loops to do so.


What A&K does do well is the ear tips that come with the AK ZERO1. There are five differently sized silicone tips (XS, S, M, L and XL), which is nice to see. These are single-flanged, wide-bore tips that should increase the sound volume and sense of space, and A&K follows up with a set of medium-sized memory foam ear tips for those who prefer a more isolating fit with a better seal and potentially damped treble response.


Given the cable comes pre-installed, a closer examination of the individual components necessitates disconnecting it. A&K is using MMCX connectors, so the cable housing on the IEM side will freely rotate 360° while locked in place. Hold the housing firmly in one hand and the connected IEM shell in the other before carefully pulling the cable out to unlock the MMCX connector without wiggling it around much to avoid any damages. I would like A&K to throw in an MMCX removal tool as with the likes of FiiO and IKKO, although these are not the hardest MMCX connectors to connect and disconnect either.