So I got to visit Estron (makers of the Linum cable) HQ...
Nov 3, 2014 at 4:08 AM Thread Starter Post #1 of 10


Headphoneus Supremus
Dec 11, 2008
When I first saw the Linum cable review here on Head-Fi, I knew I had to get my hands on that cable. I wear my CIEMs for 6-8 hours a day, so as much as I like the look of big, fat cables, I need something super flexible that just disappears. Wireless would be perfect, if it wasn’t for the quality loss, signal interference and battery hassle. The Noble cable (and the Magnus before it) had long been my benchmark cable when it came to flexibility, but this new skinny cable seemed to be in a league of its own.

Linum Bax w. T2 connector, next to my Noble cable w. angled 2-pin connector.
Imagine my surprise when I found out that this new cable came from a Danish company located only half an hour away from my house! I shot them an email asking about a Danish reseller and the possibility of ordering an unterminated cable, but got a reply from some dude named Allan that they didn’t sell unterminated cables. It turned out that “Allan” was Allan Sørrig, founder and co-owner of Estron, the company behind the Linum cables. I somehow managed to talk him into loaning me a Linum Bax cable - which I promptly re-terminated from 2.5mm TRRS to 6-pin Hirose:

(Don’t worry, I got Allan’s permission before taking my soldering iron to the loaner cable)
I immediately liked the ultra low weight of the Linum Bax and the way it simply felt like I wasn’t even using a cable at all - but I also noticed a change in the sound. The Linum Bax cable has an impedance of 1.5Ω, which doesn’t sound like a lot, but it was enough for me to notice the change. The overall volume dropped a bit but it also changed the tonality, making everything sound ever so very slightly warmer and reducing the soundstage a bit. I wrote back and forth a bit with Allan and we had a good talk about the cable, what it did right and what I believed needed improvement. One thing lead to another and he ended up inviting me to visit Estron HQ to have a chat, see how they make their (rather unique) products and have a listen to some of the prototypes straight out of the Linum skunkworks.

Left: Carit, Global Product Manager, Right: Allan Sørrig, Sales Director and Co-owner
I got to hang out with these two guys for the better part of 3 hours and to play around with the new version of the Linum Bax cable as well as some unreleased prototypes. I also had my first encounter with the positively tiny Linum T2 connector. It’s been available with Cosmic Ears ciems for some time but Allan & Carit are in talks with other players in the industry, hoping for a wider adaptation. After seeing and trying it IRL, I really hope the T2 becomes the new standard. Aside from being super compact, it locks in place much better than the old 2-pin could ever hope to do and unlike the clunky MMCX, the T2 maintains a rock solid connection.

Meet the gang: Angled T2, my DIY angled 2-pin (not connected), the tiny Linum 2-pin, Linum T2 (not connected) and a recessed T2

Linum 2-pin, T2 and MMCX.

The new angled T2, for those of you who can’t decide if you want the cable to go over your ears or down the front
For all you Roxanne owners out there, don’t worry: There’s a balanced T2 connector/socket in the works, giving you 4 connections per side along with a matching 8-conductor Linum cable. I don’t have the Roxanne myself, but I’ve seen some muttering here on Head-Fi about less than optimal connections with the proprietary cable from JH. Good to see that some manufacturers are listening to the community! This new balanced version should be available at the beginning of next year.
Speaking of listening to the community: I got to try the new Linum Bax cable. It’s now longer overall AND with a longer y-split, a direct result of Head-Fi feedback! Apart from the length, others (myself included) had remarked on the cable impedance and wished for a lower impedance version. I understand that using such insanely thin wires will result in higher impedance, but I was hoping that it would somehow be possible to make something that was still flexible, but didn’t alter the sound….


Say hello to the 0,75Ω Linum prototype. Carit had just finished building it the day before my visit. It’s thicker than the 1.5Ω version, but still very, very light and flexible. Due to the termination (2.5mm TRRS at one end, T2 at the other) I couldn’t try it on my own gear but it sure sounded delicious on the AK240 and universals. I’ve begged Carit and Allan for a loaner cable and I’ll keep pestering them for one until they give in. I need to try that cable on my own rig for at least a few days. It could very well be the perfect balance between weight, flexibility and sound, but it’s too early for me to say anything definitive. Sadly, it looks like the low-ohm version won’t be in production until 2016 but there might be an option to have one of them hand built in Denmark on request sooner than that - but at a higher price.

Meet the A/B/C/D box!
One thing was clear when I visited Estron: These guys are serious and methodical. No offense to other cable makers, but we’re way past gut feelings, vague promises and snake oil here. I got to try A/B testing between a 1.5Ω cable and a 4Ω version and the differences were clear - I could also easily hear how one might actually prefer 4Ω to 1.5Ω, depending of the rest of ones gear and the music being played. Most Head-Fi’ers have heard the argument that our sonic memory is so short that by the time we’ve swapped headphones or cables, we will have forgotten the fine details of how that other cable sounded. Well, here’s a solution to that issue:

Universal IEMs with two sockets each, allowing Estron to hook up two cables to one set of IEMs at the same time. Then it was simply a matter of switching back and forth on the box while my DX90 fed Allison Krauss through all the cables.

I ended up preferring the 1.5Ω cable but I could definitely see the appeal of the 4Ω version too. Sadly I didn’t get to try this with the 0.75Ω up against the 1.5Ω, but perhaps I’ll get that chance another day.
After playing with the end products, Carit gave me a short tour of the heart of the operation - manufacturing the mind-bogglingly tiny wires used internally in CIEMs and hearing aids.

Quality control requires a microscope, steady hands and skilled workers

150 kilometers of wire, going at 2600rpm
To give you an idea of exactly how thin these wires are, these spools were about the size of a beer can and each of them holds 150 kilometers (93 miles) of wire. Oh and the machine was winding them at 2600RPM - we had to use a special strobe light to see the arm moving up and down, carefully ensuring that all 150 kilometers were wound without a snag or tangle.

A perfectly calibrated machine adds a perfectly calibrated amount of tin to 4 perfectly cut 30mm lengths of 0.05mm wire

It might look like a clown wig gone bad, but it’s actually a bunch of hair-thin wires in a variety of colors.
Visiting Estron was a great experience. I got to hang out with like-minded people and geek out over cables and connectors, while trying new prototypes AND getting a look behind the scenes. Thanks a ton to Carit and Allan - both for inviting me but especially for actually listening to feedback from our community.
Nov 3, 2014 at 5:37 AM Post #2 of 10
Nice review. I like my Linum (music) cable but I absolutely hate the fact that the Y-split is so very near my face. That will be the very one reason I will consider getting rid of it. It's an unforgivable design oversight in my view.
Nov 3, 2014 at 6:13 AM Post #3 of 10
  Nice review. I like my Linum (music) cable but I absolutely hate the fact that the Y-split is so very near my face. That will be the very one reason I will consider getting rid of it. It's an unforgivable design oversight in my view.

I never had that problem, but I've seen others complain about it too. I would have liked the cable to be longer overall though, so I'm happy they addressed that as well.
Nov 3, 2014 at 8:23 AM Post #4 of 10
Nicely done! I do like my cable although a bit more length wouldn't hurt. Every once in a while I do find it a bit short but I can see how many would prefer a longer cable.

Any idea when these new cables will be available?
Nov 3, 2014 at 8:52 AM Post #5 of 10
Nicely done! I do like my cable although a bit more length wouldn't hurt. Every once in a while I do find it a bit short but I can see how many would prefer a longer cable.

Any idea when these new cables will be available?

AFAIK, the new (longer) cables are shipping now, but best ask Estron about it :)
Dec 3, 2014 at 7:46 AM Post #7 of 10
Just updated all the pictures in the first post because I bought Photoshop this weekend and needed an album to practice on. 
In other, slightly more interesting news, Allan from Estron has sent me something very nice to play with:

(Sorry for the crummy phone pic)
It's the new Linum IC cables! 20cm up front, 40cm in the back. My Left K10 for scale. I have kindly informed Allan that there is no way I'm returning these. They're thicker than the Linum Bax, but much thinner than any other IC I've had. Here's the 20cm version with my DIY silver IC:

(Phone pic again, sorry)
For me, an angled connector would have been ideal, but the Linum connectors are so compact that they actually don't extrude much more from the amp or dap than my shortened Neutriks. Now if only they'd make an equally compact angled version...
Sonically it's too early for me to say anything, but I haven't noticed anything bad either. Connecting my DX90 to my PB2, everything just sounds right so far. I'm coming straight from the DIY IC in the picture above, a solid core pure silver contraption made from a CIEM cable that turned out to be just too damn stiff to actually use with CIEMs.
Feb 19, 2016 at 10:50 AM Post #8 of 10
A few years after your visit, I wonder how your Linum experience is now?
Mar 26, 2016 at 3:28 PM Post #10 of 10
  Still rocking my Linum cables, still loving them. Still haven't had any issues with them, so durability sure isn't a concern :)

I'm just waiting for the Super Bax to be released,
I have the Linum Balanced on my Shure SE535 but waiting for the Super Bax to go with my ACS customs (as these already come with Linums)

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