Hardware Reviews

Tellurium Q Ultra Black II: back in black

Tellurium Q Ultra Black II power cable review https://the-ear.net

Tellurium Q Ultra Black II power cable

In the past five years of reviewing audio products, I have had quite a few pieces of Tellurium Q cable through my system and I can say with hand on heart that not once have I been disappointed by what they have delivered. In fact it was almost exactly two years ago that my review of the less expensive Black II mains cable was published, so I thought it was more than about time to hear its bigger and more expensive sibling.

I have also visited company owner Geoff Merrigan at his development and testing suite, and have been always been impressed by his hospitality, his modesty and his incredibly meticulous attention to every detail from design concept to manufacturing technique and quality control. He is a materials scientist by training, so for him this venture is an opportunity to broaden his knowledge with every iteration of cable that is developed. In my own system I have several pairs of Tellurium Q interconnects, a pair of their Ultra Black II loudspeaker cables and a couple of mains leads bearing the Tellurium Q logo, so I started this mains cable review pretty confident that I knew what I might be letting myself in for.

Tellurium Q Ultra Black II power cable review https://the-ear.net

In terms of physical appearance, the Ultra Black II has Furutech hardware at either end, which is never a bad thing in my experience. There is a typically chunky UK plug at one end and a similarly hefty IEC connector at the other. At the plug end the black heat-shrink shroud bears the model name and at the other is the manufacturer’s name. In between the wire itself is covered in a closely woven black sheath. Unlike some higher end mains cable the Ultra Black II has a reasonable bend radius and is easy to work with in the confined space between the rear of my rack and the wall. For one review I actually had to physically move the rack forward several inches to prevent particularly unyielding mains cable pushing a component off the rack, so any cable that doesn’t put me through that hassle is a good thing.

The listening test

At the start of the review period I happened to have a relatively modestly priced NAD C3050 streaming amplifier in for a review. I installed it in the rack and initially let it warm up and play for the first few days using the stock mains lead supplied in the box. To be fair this is rare for me as I usually like to give any amplifier the best quality mains feed that I have on hand, in order to allow it to give of its best. But the C3050 sounded very good, delivering great sound through a pair of Dynaudio Contour 20i standmount loudspeakers.

Tellurium Q Ultra Black II power cable review https://the-ear.net

After a couple of days listening I swapped out the rather modest lead and plugged in the Ultra Black II. Now one has to bear in mind that this cable is about the same price as the amplifier into which it was plugged, so this was hardly a real world scenario, but the effect on the sound was very obvious from the outset. Streaming from a hi-res Qobuz file of Dave Alvin’s Eleven Eleven the sound took on an extra level of realism, with a noticeable improvement in three dimensional sound staging, with Alvin’s baritone gaining extra weight and realism. We are not talking a doubling in sound quality commensurate with the doubling of the price, but definitely a distinct improvement. Switching back and forth between the standard mains cable and the Ultra Black II over the next few days confirmed this impression.

When the C3050 review was over, I slipped my Lyngdorf TDAI3400 into the amplifier shelf and repeated my experiment, swapping between a standard mains cable and the Tellurium Q. In theory the all-digital 3400 really ought to be impervious to such a change, but even here playing the same litany of tunes as before, everything seemed to improve. Bass seemed a tad faster, the midrange took on extra realism and the higher frequencies gained air and lightness. Once again I switched the mains cables back and forth, but could hear the improvement every time the Ultra Black II  joined the party. It wasn’t a fluke.

Ultra Black II Power 2 1024x576 1

I then went through similar processes with the Ultra Black II into the power supply of my Gold Note PH10 phono-stage, with the standard mains lead back in the amplifier. There was an audible improvement in the sound but it was not as pronounced as it had been through the amplifier.

At that stage in the Ultra Black II ’s time here, the Dynaudios were removed from the scene and my own Harbeth Compact 7ES XDs took over loudspeaker duties. At the same time the Kleio K135 Class D integrated amplifier had arrived so that took over at the heart of the system. I ran this with its supplied mains lead from the wall socket initially, and was soon very appreciative of its music making through the Harbeths. Playing vinyl via the Gold Note two box phono-stage took things up a notch. The recently released half-speed remaster of the Who’s Who’s Next sounded absolutely compelling. I then switched in the Ultra Black II  and was almost pinned into my listening chair. Without changing the volume setting on the K135 the whole thing seemed to have got louder, with an additional level of heft to John Entwistle’s already thunderous bass and Keith Moon’s drum kit. For a record made more than half a century ago I felt that I was in a live concert setting, it was really that immersive. Needless to say this was pretty addictive, and album followed album, always with the same effect.

Most recently the Kleio has gone and been replaced with a less expensive Roksan Attessa, but now with a pair of GoldenEar T6s doing loudspeaker duty. Did I mention that it is seldom dull around here? Now the Attessa is a sub £2k Class AB amplifier with lots of digital and analogue options on the input side. It produces a very healthy 80 watts into 8 Ohms and 130 watts into 4 Ohms. By now you will be able to hazard a good guess at what happened. Switching from standard to Ultra Black II  cabling from the wall socket had the most dramatic effect of all. My goodness what a glorious sound burst forth from the T6s. I played Who’s Next again and kept advancing the volume, expecting that at some point the whole thing would collapse into unlistenability, but I was wrong. Every piece of music I played gave me the same visceral experience. Only when Mrs K returned home did I back off the volume, but it had been quite a day by then.

Tellurium Q Ultra Black II power cable review https://the-ear.net


If you are a paid-up member of the “cables don’t make a difference” club then I thank you for reading this far, because it must all grate rather horribly. I listen to various configurations of audio gear pretty much every day of the year and I am in the opposing club because I hear those differences every time I change a cable anywhere in the system. To be fair, while I have known for a very long time that interconnects and loudspeaker cables make an audible difference, it took me a while to realise that the one and half metres from the wall to the system are where I should have started in the first place, and then worried about the other cables. The amplifier sits at the heart of the system, just as an engine sits at the heart of a car. The quality of the fuel dictates how efficiently that engine runs, and that analogy carries through to our audio hobby. The better quality of power that flows into the power supply of the amplifier (or any other component for that matter), the better the amplifier will perform.

Once again Mr. Merrigan has proved to me that he is still at the peak of his considerable powers, so yes, he has succeeded. It is counter-intuitive to use such an expensive mains cable on a relatively modest amplifier, but I am now convinced that it is actually money well spent. If you have an amplifier in the hotly contested £5k region, you really should ask your local Tellurium Q dealer to let you hear one of these on your system. Save your ‘snake oil’ barbs, this cable is the real deal.


Type: UK 13A to IEC mains cable
IEC terminator: Furutech
13A mains plug: Furutech
Diameter: not specified
Conductor material: copper
Dielectric: not specified
Length: 1.5m

Price when tested:
Manufacturer Details:

Tellurium Q


power cable


Chris Kelly

Distributor Details:

Kog Audio
T 024 7722 0650

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