Reviewer: Srajan Ebaen
Financial interests: click here
Sources: Retina 5K 27" iMac (4GHz quad-core with Turbo boost, 32GB RAM, 3TB FusionDrive, OSX Yosemite. iTunes 12.2), PureMusic 3.02, Qobuz Hifi, Tidal Hifi, Fore Audio DAISY1, COS Engineering D1, Aqua Hifi La Scala MkII, AURALiC Vega, Aqua Hifi Formula [on review], Resonessence Veritas [on review]
Preamplifier: Nagra Jazz, Esoteric C-03, Vinnie Rossi LIO (DHT module)
Power & integrated amplifiers: Pass Labs XA30.8; FirstWatt SIT1, F5, F6; Crayon Audio CFA-1.2; Goldmund Job 225; Gato Audio DIA-250; Aura Note Premier; Wyred4Sound mINT; AURALiC Merak [on loan]
Loudspeakers: Albedo Audio Aptica; Sounddeco Sigma 2; EnigmAcoustics Mythology M1; soundkaos Wave 40; Boenicke Audio W5; Zu Audio Druid MkV & Submission; German Physiks HRS-120; Eversound Essence, Boenicke W11 [on review]
Cables: Complete loom of Zu Event; KingRex uArt, Zu and LightHarmonic LightSpeed double-header USB cables; Tombo Trøn S/PDIF; van den Hul AES/EBU; AudioQuest Diamond glass-fibre Toslink; Black Cat Cable redlevel Lupo; Arkana Research XLR/RCA and speaker cables [on loan]
Power delivery: Vibex Granada/Alhambra on all components
Equipment rack: Artesania Audio Exoteryc double-wide 3-tier with optional glass shelves, Krion amp stands
Sundry accessories: Acoustic System resonators, Verictum Silver X block on preamp and amplifier
Room: Rectangular 5.5 x 15m open floor plan with two-storey gabled ceiling, wood-sleeved steel trusses and stone-over-concrete flooring
Review component retail: €240 [incl.19% VAT] standard, €344 [incl. 19% VAT] industrial

Uncertain shaky biz. USB for short? Ha! That'd overreach. But it's certainly true that of late, the USB interface has been under heavy attack from a glut of black boxes whose users claim very audible improvements. What does that say about raw USB? Intona Technology GmbH from Germany would probably quip that it may be cleaned up. Their USB Isolator comes in standard and heavy-duty versions. It's meant for industrial automation systems, measurement devices, environments requiring safety insulation, machine protection, broadcast and studio and all applications that rely on clean and stable USB connections with separate grounds. If your inner hifi freak felt left out, here is the company's Sven Beck. "Our first real Hi-Speed Isolator for USB 2.0 gives huge benefits to audiophile-grade home systems." It's simplicity itself. In goes the USB feed from your computer, out comes the now galvanically isolated reclocked repacked DAC feed regardless of transmission speed.

If you've already read the tea leaves to think that our smartly called Intona was not originally developed for audio, spot on. It wasn't. It came about as an antidote to noise plaguing laboratory and industrial environments where clean measurements had to reach deep into the nanovolts domain. This mandate on required noise attenuation instantly nixed any external SMPS. Instead it led to a USB-powered design. The industrial version of the German isolator has higher-spec'd parts and at 2.5KV the higher isolation resistance (the standard box is rated for 1KV). Because Intona had previously worked on pro audio mixing consoles, they claim to have paid special attention to the frequency range which concerns our audiophile tribe. In short, the Intona operates as a receiver, isolator, reclocker and repacker. It uses buffers, a ULPI transceiver, field-programmable gate array logic on two Spartan chips, minimum-capacitance Silicon Labs Si8660 digital isolators, spread spectrum tech to eliminate 8kHz packet noise, a DC/DC converter and an Analog Devices linear regulator. If you want to get even nittier and grittier on the tech, download the firm's data sheet. And yes, you'll need two USB cables, one coming in, one going out. Whether the first one—between PC/Mac and Intona—can be a 'nasty' generic since the important stuff happens past it is a good question. It's something I'd have to try. Either way, drivers aren't required. Whilst USB of course claims to be plug'n'play yet is so susceptible to widely reported improvements from reclockers or ground isolators, the Intona means to really be plug'n'play. Which won't prevent the nuttiest of our tribe from slaving multiple Intonas (or their brothers from another mother) in series to get even mo betta. Fear not. Your scribe won't.