AIM NA9

REVIEW
Alan Sircom
Sep 25, 2025

Sometimes, we get cables from brands with a ‘limited’ heritage in manufacturing and design. That’s not the case with Japanese comms expert AIM. AIM has been manufacturing enterprise-grade digital cable systems since 1983 and has developed domestic digital cables for audio and video in Japan since 2006. It knows its way around an Ethernet cable because AIM has built network infrastructures for Universal Studios Japan, Osaka’s Kansai Airport and Nippon Telegraph and Telephone. The NA9 is AIM’s flagship domestic Ethernet cable.

Aside from the colour of the cable, AIM distinguishes its NA9 from its NA6 and entry-level NA2 cables by using what it calls ‘Hoplon’ construction. Its conductors are eight solid cores of AWG 22 oxygen-free copper, arranged in four twisted pairs. Hoplon features an inner layer of shielding that uses Aahi Kasei’s Pulshut^®MU electromagnetic insulation sheets around a twisted pair. The Pulshut^®MU layer is then screened by an aluminium shield, a copper shield, and an even higher-density copper braided shield. There is insulation between each layer using AIM’s proprietary sheathing material. These shielding layers contribute to a different part of the overall performance. The cable is terminated using the latest Telegartner connectors.

Extremely well made

This sounds impressive, but only when you get the cable in your hands do you realise what this means. It’s a highly well-made cable. NA9 is the kind of cable that will still work decades from now. This is also a cable unfazed by anything we audio enthusiasts can throw at it. It’s the Ethernet equivalent of bringing a gun to a knife fight.

In less violent terms, it’s the sense of infinite reserve you might feel from the back seat of a Rolls-Royce or a Maybach cruising at about 40mph. You could play anything from a stripped-down Audible AAX or MP3 file to the final bars of Mahler’s Eighth on the fattest files possible, and the AIM NA9 takes it all in its stride. If ‘it does precisely what it should’ sounds like faint praise, when you hear how many of its rivals fail to achieve this all-round goal, you begin to appreciate AIM’s ‘belt and braces’ approach.

Different demands

We’ve found that Ethernet’s packetised data places different demands on musical content than more traditional S/PDIF and AES digital cables. If anything, the cable’s imprint on music has more in common with USB. It seems to be about keeping noise in check. That noise is cross-conductor electromagnetic noise caused by upstream routers and switches, as well as RF interference that undermines specific parts of the frequency band. The former compresses image space and soundstage, while the latter affects both low and high frequencies. You become more aware of the sound quality limitations of Ethernet cables when you use a cable like AIM’s NA9. This is because it keeps those limitations to an absolute minimum. Staging is as good as the original file, while bass and treble extension are kept as wide as possible, pushing the sound’s limits onto the amp and speakers.

If there is a ‘blameless’ audio product, AIM’s NA9 Ethernet cable is closer than most. This is one of the cleanest-sounding Ethernet cables I’ve tried, not just in terms of improving the sound, but also in absolute fidelity to the original music. It’s not going back!