Triangulations. Both Nord's interpretation of Ncore 500 and Auralic's—of uCD400 strategically modified to lower THD of the stock module beyond the 4th harmonic—were similarly warm to Purifi. Within such a shared climate however, the first two also presented lower magnification power. Both sounded thicker, less nimble and, on a whole, slower, cozier and by contrast somewhat opaque and micro-dynamically lazier. To my ears, they felt like a deliberate attempt to inject some 'tube' warmth with its usual companions of subtle fuzziness, lower separation, less articulate layering and sacrificed micro detail. Whilst an undeniably pleasant listen, a superior class AB amp like our direct-coupled ultra-bandwidth LinnenberG Liszt calls out that form of pleasantness as a coloration. It works like cotton batting or a soft suspension. Being no less pleasant but rather, more so, the Liszt are demonstrably more resolved, communicative, quick and lively. Plus, they express an undeniably superior top end.

I quickly stopped wondering whether Purifi's implementation was superior to my class D alternates—it clearly was—to start wondering how it might hold up against the best high-power transistor amps we can afford to own. For these sessions then, I reverted to our status quo, albeit with enhanced source resolution via Mutec's USB bridge aka D/D converter. This was additionally reclocked by their own reference external master clock to insert between our discrete R2R Denafrips Terminator and music iMac with locally hosted files. Preamp was our usual Wyred4Sound STP-SE II. At our SPL, that quasi passive operates with zero voltage gain but its active i/o buffers guarantee constant impedance and proper current drive.

This last juxtaposition of amplifiers, of Purifi vs. LinnenberG, proved far closer than expected. On tonality, soundstaging and resolution in fact, I thought these very disparate designs very much on par. Small remaining offsets were about textures, perceived speed and top-end energy. I'd recently combined the Liszt monos with Gryphon's Zena preamp. For the first time, this had married our power amps to a preamp of equally exploded bandwidth to maximally complement their advantages. This had further elevated the same aspects which now segregated LinnenberG from Purifi. It explains why I felt inclined to believe that ultrasonic bandwidth was in fact the primary cause. So what were these differences?

On textures, the DC-coupled class AB amps acted shinier and wetter. The Purifi amp played it more matte and dry. On transient keenness, the LinnenberGs played it quicker or steeper, thus with more incisiveness and startle factor. On treble sparkle and overtone spray, they went further. On exceptional recordings like a raw studio folder of a flamenco album by guitarist Adam del Monte prior to mastering—owning the commercial CD for contrast, the final mastering process diminished its dynamic range, bandwidth, jump factor and liveliness—these differences were meaningful. On more mainstream fare of lower production values, the delta shrunk closer to a sideways preference. Depending on listener, it could go either way to fundamentally elude a better/worse rating.

In my book on solid-state amps, the LinnenberG Liszt for high power and Bakoon's AMP-13R for low are prime examples for fast sonics which are lit up all over. That qualifier distinguishes the effect from the imbalance of just a forward treble. If you've heard a bright treble, apply its quality all over across the audible bandwidth. Now it becomes a linear or complete instead of partial so skewed aspect. That's the presentational difference which I heard between our more energetic shinier reference amps and the mellower softer Purifi demonstrator. At €8'500/pr, the German monos cost what they do. For what type coin should we expect Purifi amps to show up in high-street dealers if we envision LinnenberG-level chassis with a mainstream even boutique name badge? How much tuning leeway is there left for custom input buffers? How much performance enhancement might arise from integration with a built-in DAC-direct connection? I haven't the faintest. But it's tantalizing to think what sundry brands will decide to cook up with these advanced Purifi modules for next-gen reference sonics which just so happen to operate in efficient class D.

Purely on what they compete against aurally, there's good reason to expect that many will be priced well upward of €10K all the way into Bel Canto Black turf again. Where it could get spicy is if the business model of Apollon, Nord & Bros—direct sales from lean outfits using modest not bling chassis—boards the Purifi train to undermine trophy hifi for cents on the euro. That's where the attentive smart money will shop. [Shown, Apollon Ncore 1200 amps with discrete Weiss input buffers and linear power supplies for certain sub circuits.] None the wiser, cachet hunters will pursue identical guts in bank-vault boxes. Regardless, all should be pleased. Natural sound has the advantage of not wearing out its welcome with cheap tricks. When accompanied by very high resolution from superior S/N ratio as Purifi propose, it should readily scale up when partnering ancillaries and recorded resolution of their users polish up. That's what gives a hifi product legs. Now a Purifi amp won't find itself the weak link of even ambitious systems anytime soon.

Fundamentally, the only real issue I envision is that the Danes will have to continue fighting die-hard snobbery which opposes class D on principle; because it's based on far earlier lesser examples or simply poor demos; or because it's plain ignorant or misinformed. Here's to some gratuitous violence from our tech vikings then as they attack that perception barrier. With Eigentakt, Thor's hammer has certainly just gotten bigger. Smashing stuff…