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, Bakoon DAC-21 [on review]
Preamplifier: Wyrd4Sound STP-SE Stage II, Nagra Jazz, Esoteric C-03, Vinnie Rossi LIO (AVC 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; Linnenberg Allegro [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, Audio Physic Codex [on review], Kii Audio Three [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 source stack, Vibex Three 11-R and DC filter on amps and subwoofer
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: €1'411 EU version, €1'555 UK/US versions, €273/€211 20A/16A Knack power cord

Gordian. Most of us remember it as a recalcitrant knot of antiquity slashed asunder by...well, some legendary hero no doubt. Actually, the story is credited to Alexander The Great. Whilst wintering at the Phrygian city of Gordium, he tried to untie an ox cart leashed to a post with an intricate knot of cornel bark. Said cart dated back to a time when the Phrygians had been without king. An oracle decreed that the next man to enter the city whilst driving an ox cart should be crowned. In remembrance, Midas tied up that cart which subsequently became a tourist attraction. When Alexander couldn't untie its knot upon his visit, a version of the tale has it that he cut it with a single stroke of his sword. Since then, cutting the knot has become synonymous with thinking outside the box. That of course means solving a problem by unconventional means; even if in popular cop shows, chain locks are invariably cracked open by gun shots, never by sword attacks.

In any event, contemporary hifi explorer Stratos Vichos of the small hifi boutique Lab 12 in Athens calls his compact AC conditioner Gordian for good reason. It features adaptable filters with auto diagnostics. So you may optimize various parameters like EMI/RF filtering, common filtration, differential filtration plus line phase aka power factor correction. Displayed analysis (which may be dimmed or turned off) includes FFT current/voltage measurements, DC, THD, power consumption, line frequency, polarity, proper earthing and AC voltage output. There are six outlets on EU, UK or US socketry. Two are high current/low filtered, four are low current/high filtered. The IEC inlet is of the 20A high-current sort. That requires a specially terminated power cord. Called Knack, Lab 12 has one for €273. One can manually run through the filter adjustments and select the best by ear. Or, 'auto mode' lets the Gordian configure itself. Its industrial analyzer constantly monitors eight different parameters at 256 samples per AC cycle. That sends 2048 measurements per interval to the main processor. Power factor correction switches in a capacitor bank but calculates the optimal value for the most effective power conversion. Over-voltage protection clamps down against catastrophic failure. In 'auto' mode, the Gordian constantly calibrates itself against its own real-time measurements. With its configurable circuits, the Gordian allows us to listen to specific actions of specific filter methods. Rather than promissory propaganda by various manufacturers, on what's best, we may compare and contrast a number of options in one unit.

Given the swath of possible AC issues, common sense predicts that an affordable one-for-all solution probably doesn't exist. Then there's moving house and kit changes. In such a context, the concept of adaptable AC filtration could be welcome. At the very least, it exposes us to the effects of different methods and their strengths. Now personal curiosity twitched. Whilst perfectly happy with my Spanish Vibex kit—double DC filtration plus AC filtering as a final choice after units by BPT, Walker, GigaWatt and Furutech—I never had a chance before to toggle through adjustable options within the same CE and RoHS certified unit. When Stratos asked for a review, I obliged.