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Srajan Ebaen
Financial Interests: click here
Source: April Music Stello 100 transport/DAC [on loan], Aura Neo & Groove [on review]
Preamp/Integrated: Peachtree Audio iDecco
Speakers: Anthony Gallo Acoustics Strada & TR3, Reference 3.5 [on review]
Cables: ALO Audio cryo links, Crystal Cable Reference & Ultra power cords
Stands: Ikea office desk
Powerline conditioning: 1 x Furutech e-TP80
Review Component Retail: 2.500 Swedish Kronen

Take it from me. Reviewers hate I²S cables. They must go into 'Special Characters' or 'Symbols' to properly spell them. Honest.

I was being facetious of course. It takes no bullshit reason to refuse such cables. The real reason is far more damning. Who needs 'em? Very few companies remain who still run with this standard for external digital signal transmission.

standard you say? The specification goes back to Philips and 1986. It originally was a low-jitter three-line bus for bit clock, word clock and multiplex data. Later iterations added one or two more lines. How about connectors? April Music uses S-Video plugs to terminate their I²S interface between the Stello 100 digital separates. Zanden Audio uses Ethernet sockets. PS Audio and Wyred4Sound use HDMI. Ancient Audio goes the full Monty with its three-box player below. That separates out the I²S multi-line bundle into eight discrete BNC-terminated wires. In the real world, what standard is there for I²S other than a 20-year+ old specification that's seen somewhat different implementations?

There must be more hifi companies who continue to run external I²S. Prudence alone dictates it. No matter, it's two handfuls at best. Any cable manufacture committing to an I²S cable today appeals to a tiny fraction inside an audiophile minority. And what termination should he offer? Entreq's Per Olof owns the Stello 100 separates. Being an inveterate tinker, he didn't resist an inquiry for a better cable than the S-Video terminated link April Music includes. His competing Entreq design caused such a 'stir' in Sweden that he told me about it*.

As it happened, I still had the April Music Stello review loaners on hand. They were patiently awaiting a bulk pickup once pending reviews of their bigger siblings had finalized. This made me one of the few reviewers on the planet who could even use the Entreq link. My immediate question was, how many readers would such a review address? Then I thought, why should it just be manufacturers who embark on the occasional labor of love? To not waste your time if such you'd consider it, stop reading now if you don't already own—or soon will—the Stello 100 units or others that run S-Video links for their I-squared-S connection. Is there anyone left reading? KBO I told myself. Keep buggering on.


*With this cable something happened that I will never forget. There is a 20-year old who works for us. He isn't deaf of course but sometimes you could think so. I actually thought he couldn't hear the difference between MP3 and vinyl. That's because he practices 'speaking is silver but silence is gold'. There are days that he only says 'morning' when he comes in and 'see ya tomorrow' when he leaves. My wife and I are chatty and go on and the only way you know that he pays any attention is that sometimes he can't help himself and smiles. I do worry about him but his parents say that he never has been as happy in his life until he started helping us.

"Whenever we had new product, I used to ask him what he thought. He used to look at me and say 'difficult to say, I don’t know'. In the rooms where we work, we have a Stello Dac and Stello U2 connected to the PC for background music. I used to have our Discover coaxial digital cable between the U2 and converter. I built three different I²S cables which were all identical except for the grounding.
To make sure they worked, I let each play for about 2 - 3 hours. Afterwards, this man came and said 'would you go back to that stuff you used this morning, it sounds so good'. I was really surprised and asked whether he could hear the difference. He answered that 'even Pontus the cat likes it better. We want it back'. It was the Swedish Stello distributor who asked me first if we could do a better cable than the standard I²S that's included. I think the I²S standard and what dCS and Mac use is similar. It works very well with dCS and Weiss so why not with Stello? This cable is built nearly the same way as our Discover FW cables. In the near future we will make an I²S Konstantin 2010 too."

Ones and zeros. There couldn't possibly be a difference with digital cables*. Yawn. Have you actually tried it to be sure? It still may make no sense to those who've performed such comparisons but it's not just about hoodwinking the gullible to sell designer-priced placebos. What could still cause upset is the foregone conclusion of parallel I²S transmission's superiority to series S/PDIF. Why expect additional differences between different I²S links? Or—cough—could a superior S/PDIF cable outclass an inferior I²S to really make the point that there's more to high-speed impedance-matched digital data transfer than meets common (superficial) sense?


*If audiophilia's obsessive-compulsive element has you draw a line to not worry about this particular matter, I'm with you. We all have our limits. With PC audio, some folks fret about which drive to use to rip their CDs to hard disk. I'm not one of them. I am, however, quite sensitive to WiFi radiation. So I use 'mysterious' devices to minimize the effects. Those who live with ear-clip Blutooth devices will find that bizarre. It's all quite personal. In the end, all this is supposed to be an enjoyable hobby. It's got to be about more than constant anxiety and endlessly chasing fractional percentage points. Whatever is good enough for you to relax and start enjoying yourself is where you should bloody well stop. Live a little.

But let's say you're still following this. The Stellos happily accommodate today's mad experiments with a front-panel selector which handily switches between I²S, coaxial, AES/EBU and optical. Having already done the deed in the big rig, I subsequently wanted to know whether and how the very obvious differences between these two I²S links would translate in the extreme nearfield. There soundstaging is scaled back. How about headphones? There soundstaging would undergo further modifications. Enter the desk top with the iDecco and Gallo Stradas; and ALO Audio-wired Sennheiser HD800s. The big-rig verdict held, albeit stepped down in impact as though to parallel the shrinkage of scale and scope here.

Either way, the stock cable was comparably opaque, energetically stepped down and less clearly or cleanly separated between images. This caused more diffuse focus. If you were to pay attention only to the 'muffler effect' in prolonged A/Bs, you should call it right each time. The stocker was thicker, heavier and fuzzier. Diagnosing why, I'd say that timing was less precise. Consequences on soundstaging—more rear-hall clarity for more lit-up spaciousness, higher image lock—were admittedly more dramatic in the big system. There A/B comparisons took no effort at all to pin and make for a very unambiguous cable swap for once. Knowing what to listen for, I could reliably track the effects on the above desktop system and notice them even on my Sennheisers. But on the latter, things were more subdued, shifting mostly between 'fresher' and 'duller', i.e. focused on transient acuity. Interestingly, low bass handled by Gallo's TR-3 sub fed line-level from the iDecco benefited a tad. It felt rhythmically more on - what Naimies call PRaT. It gave certain tunes greater bounce and boogie factor. On revealing vocal tracks, the Entreq also had somewhat greater sweetness particularly on emphatic peaks.

Per Olof's taciturn worker called it right then. Entreq's I²S link does make a nice and quite substantial difference. It's meaningful only for those of course who own the Stello CDT100/DA100 Signature. Then it should be most relevant on time-coherent speakers with a clean impulse response. On those it's far from "maybe yes, maybe no" as a friend's kid once spent an entire afternoon answering each and every question put to him. With Entreq's I²S Discovery, it's an unequivocal yes. Kudos to these Swedes for bothering with something so few prospective punters could even be interested in (which still doesn't mean they would). That I call a labor of love for sure.

Entreq website