Closer Examination

The cable A&K uses on the ZERO1, as well as the whole made in Japan part, is highly indicative of some help from Acoustune here, with the cable in particular certainly looking like a for A&K rebranded Acoustune product. This is a good thing since Acoustune cables are well-established for a good reason. This particular cable starts with a 3.5 mm TRS single-ended connector from the source going to an aluminium plug housing, and we see a plastic cover on the plug, as well as strain relief where the cable meets this 90° angled housing with its machined finish. The cable uses silver-plated oxygen-free copper conductors in four neatly braided cores, and it looks quite the part paired with the IEMs, too. There is a matching splitter with the A&K logo, as well as a cable cinch which not only functions very well, but does so while looking like a natural extension of the splitter itself. These are the details I want to see from a more premium brand, and it continues on the other end with the two MMCX plug housings. Notice the plastic sheathing on the cable that helps with the pre-formed ear hooks that have the cable go behind your ears naturally. The two connectors come with blue and red plastic inserts in addition to "L" or "R" markings for the respective channels. All three connectors are gold-plated for oxidation resistance, and I found this cable to be very good in terms of fit and finish, with no microphonics, kinks, and resistance to re-shaping.


I have seen a few of the other A&K collaboration IEMs in the past, and they all tend to have a different aesthetic involving the other participating brand. This time, given the AK ZERO1 is entirely an A&K product, we see a relatively clean aesthetic involving a fully CNC-machined aluminium composition. There are three separate aluminium sections including the black anodized shells, cover to close off the acoustic chamber that just peeks out of the black shells, and face plate that is screwed onto the cover internally. This results in two separate interfaces, and a gap on the outside of the face plate that I would have rather seen extended and bent over the sides of the shells to minimize dust or contaminants getting stuck in there. Otherwise, this two-tone color scheme works out well in terms of general build quality and aesthetics.


A closer look at the face plates reveals there is more going on here, with curves emanating from the middle and going in before curving back out at the edges. This is also a quite durable sand-blasted finish with plenty of grip to hold on to the IEMs. A truncated A&K logo is etched into the face plates for branding, which does the job without being obnoxious. The side view reveals a small vent that provides airflow to the drivers and helps with pressure equalization in use, with the gold-plated MMCX female connector flush with the sides of the shell. The shell design is somewhat ergonomic despite the highly angular nature of things, and an "L" or "R" marking for the respective channel has been put on the inner side. Given these do not come with ear tips pre-installed, we can examine the nozzle right away; it forms out of the unibody shell construction and juts out with a small notch on the end to retain the ear tips in use. This reduces the likelihood of damaging these IEMs when dropped, which is always nice to see. A metal mesh is placed on the end of the nozzle to prevent contaminants from entering the acoustic chamber, and there are three vent openings for the sound field to enter your ears.


As mentioned, two types of ear tips come with the AK ZERO1; silicone in five sizes and foam in one. Try them all out to get the best-possible fit, and consider tip-rolling if these don't seal well enough. Notice how the silicone tips are shorter on the nozzle, which makes for a deeper fit in the ears if your concha accommodates the shells. Regardless of which tips you go with, the next step is to re-connect the cable by carefully identifying the matching channels and orienting the ear hooks to go around your ears naturally when connected to the IEMs. Doing so is extremely simple since you just push the male ends of the MMCX connectors into the female ones on the IEMs, and the free rotation from these connectors means ear-hook positioning can be done at any time. Now, simply connect to the source using the right-angled 3.5 mm TRS connector on the other end of the cable. I know there are many who prefer using IEMs throughout, but I like to use over-ear headphones when sitting down and IEMs on the go. I paired the AK ZERO1 with all the tested portable DAC/amps to date and personally like the cleaner profile and handy EQ options of the Qudelix-5K as the source, in turn paired to my phone or laptop.