Let’s get the difficult part of this review out of the way. Tellurium Q doesn’t publish specifications – in part because it doesn’t want to hand over its trade secrets to its rivals, and in part because there’s a tendency for people to make odd proclamations about sound based on materials alone (“it’s a silver cable, and as such it sounds shiny”). While this is entirely understandable from a commercial proposition (Tellurium Q is not alone in this; Kubala Sosna is also reluctant to disclose details of its designs), it does make it difficult to explain ‘how’ Tellurium Q cables sound as they do, and ‘why’ one cable might perform better than the next in line. The nearest we get is that the cables are designed to eliminate phase distortions in general and the digital cables are good at removing the demon problem for all things onesy-noughtsy... jitter!

Worse, there is an increasing rejection of the need for aftermarket cables, and that rejection is focused in particular on digital cables, and most especially USB. In a way, that isn’t important; ‘how’ and ‘why’ a thing makes a difference becomes academic when you are ideologically opposed to it making a difference in the first place. The growing ‘bits-is-bits’ chorus would likely reject any description of the concepts underlying Tellurium Q’s cables as so much snake oil anyway. So, maybe dispensing with the ‘why it does it’ is not such a bad idea, after all – for the manufacturer, at least.

We were given a range of Tellurium Q digital cables for test; five in total. Black and Graphite (in USB and 75-ohm coaxial S/PDIF configuration) and Black Diamond (available in USB only). The prices of these cables ranged from a smidgeon under £300 for the Black USB, right up to a frisky £740 for the Graphite coaxial. There are also digital XLR cables for AES/EBU installations in the Black and Graphite lines, priced identically to their S/PDIF brethren. They all have a common character to the performance, and that performance does improve as we move up the lines in fairly clear steps, so most of the test concentrated on extracting the most from the best; the aforementioned Graphite, and the £660 Black Diamond.

To do this, I simplified my system to its barest bones; a computer, a CD transport, a Wadia 121 DAC, which I used as headphone amplifier into a pair of Philips Fidelio X1 headphones. By way of comparison I used my usual Nordost Blue Heaven USB. The only hiccup here was the CD transport; although I’ve still got all my CDs, most of my digital listening is now through computer and I had to borrow that front end (the B.M.C. Audio BDCD1.1 tested by AS last issue) and acclimatise myself once more to spinning discs. I also borrowed a Nordost Blue Heaven S/PDIF for consistency.

This turned out to be an interesting and almost immediate overtuning of any ‘bits is bits’ mentality I might have still been harbouring. It’s actually irrelevant which Tellurium Q cable you select to compare against its Nordost opponent, it’s more that the difference in the nature of the performance of both ‘families’ is so huge as to render the ‘bits is bits’ idea laughable to any listener. Curiously, I had expected this difference to be less significant, because both Nordost and Tellurium Q have a reputation for leading the field in leading-edge resolution. This turned out to be correct, but after that things went in very different directions. Put simply, the Nordost had more energy, and the Tellurium Q cables were darker sounding.