Plasticity. Where Intona minimize annoyance over the inherent pimp-my-costly-DAC prospect is forgoing casing bling. Hifi can be notorious for style over substance. Last century's guts may repack in glam threads. Likely because Intona's first customers were laboratories and industrial safety apps, their plastic cases bypass all bling pretensions. Remembering that in hifi, the case is routinely the costliest part, Intona would seem to go straight for performance. Even posh hifi customers won't care. As a USB Isolator, this box should end up behind their DAC out of sight and mind. And unlike the wall-wart brigade with their cheesy Chinese switch-mode supplies which inject the power line with HF noise, the Intona neither creates such noise nor eats up yet another power socket. By the same token, it can't be upgraded with a linear power supply to drive up cost and complexity. Whilst its mere existence might still irk reasonable people because it wags a finger at our USB DACs, at least the degree of irk is contained including the price. Given the type of percentage-chasing hifi user who'll be most interested, at a fraction of the cost of their designer power cords, Intona's sticker is low. For a final intonal blessing by an imaginary hifi pope, consider Dennis Morecroft's research on the ill effects of metal casings on audio circuit performance. His DNM Design brand has long since championed acrylic boxes. Along his line of reasoning, today's USB Isolator might actually work better for sitting inside a cheap plastic box than costlier metal cage. Which about covers all the introductory angles I can think of. Time to audition!

Act One. My work desk emphasizes work. That's a multi-tasking circle jerk. At any one time, my HP Workstation Z230 will co-host Photoshop, DreamWeaver, Adobe PDF reader, Word, IpSwitch, Opera, Internet Explorer, Chrome, Outlook, the SD card reader, MalwareBytes and other security services plus Tidal or Qobuz. This runs massively paralleled threads and processes to load down the CPU. It's the antithesis of the music-only server/renderer which, whilst still a computer in disguise, runs nothing but playback-specific programs with hardware tweaked for just audio. In short, it's an infected breeding ground for compromised USB audio. Or so the propaganda claims. Of course if things did sound too swell, I might get no work done. But to test the Intona, work would mean critical listening on the desktop for a change. This made it the perfect real-world test bed. It runs the Swiss Eversound Essence active speakers which since were rebranded Feniks Audio to now sell direct. Their Polish designer commissioned his 24/96 USB DAC, preamp and headphone amp from PCfi's god father Gordon Rankin. ICEpower runs a custom 4.5" coaxial in a compact precision-cast aluminium enclosure whose port fires down into an integral plinth. Until KEF's launch of the LS50 Wireless—which I haven't heard yet—the Essence was the highest-performing dedicated desktop speaker I'd come across. At its original €2'760/pr price, it'd better have been. Think small, pretty and wow. The usual USB cable here is a 50cm Curious. For the second, enter not oxycodon but the oxymoron of an upscale generic: a clear plastic jobbie with braided silver shield and two small ferrite clamps. It's what local mass merchants hawking computers, printers, cellphones, hifi, TV, washers, dryers, shavers and kitchen appliances call their best option. It's two steps up from a freebie throwaway packed with a new printer. But propaganda still sees it as an amoeba to humans on the evolutionary ladder of proper audio USB cables. I'd swap cable positions to track impact. Music source was my Tidal subscription to stream 16/44.1 from a personal playlist; and a few RedBook-and-higher files stored on the HP and processed via J.River Media Centre for just these occasional desktop kit reviews.

Very demonstrably, the Intona removed splashiness, etch and glare. Think of those as constant spittle flying off a singer's lips rendered in macro closeup. You really don't want to see that. Yet with typical close-mic'd productions, that's quite routine. One hears this spittle-like effect coming off plucked strings, plosives, transients in general. It sizzles like an image oversharpened in Photoshop. Not only are edges in crisper relief, one begins to see 'noise' surrounding items as pixel flecks that shouldn't be there. By simply pausing Tidal and reseating cables—and when the Intona was in the loop, waiting for the signal lock lights to stop flashing—I could contrast with/without in seconds. Without doubt, the Intona removed that pixilated noise. This improved the quality of tone which no longer suffered the injection of whitish nervy hash. It became richer and calmer and a certain hollowness filled out. If you imagine it without loss of detail, it'd move a microphone away a bit from a string instrument's bridge or a singer's lips to not highlight the spitty metallic bits. This away-moving effect—really, the elimination of artificial glare—shifted tonal emphasis a bit more on the bloom than rise portion. Subjectively, the music felt weightier and more relaxed. An unnatural hype or striation which only newbies would mistake for higher resolution had been bled out.

A green square indicator on each end of the Intona confirms signal lock when steady; and no lock when blinking.

This effect became even more pronounced when the better Curious cable connected the Intona's output to the Essence DAC's input. If your two cables are of different quality, the better one should tap the DAC not computer. Don't know which the better cable is? This A/B might just settle it. So, Act One ended in a standing ovation. For €344, my inner hifi accountant called it a most worthwhile upgrade. Would the victory lap extend to the big rig?