My menagerie of hardware culminated in these glass-clad Audio Physic 4-way Codex. It made for a context of well-sufficient gain to run Purifi's demonstrator with bypassed buffer. The Ncore 500 monos obviously wouldn't run 'nude'. Their sound would be greatly influenced by Nord's input buffer with discrete Sonic Imagery opamps.

Damping factor. With class D, very high damping factor from very low output impedance tends to be a loudly advertised fact despite inevitable resistance of interconnecting speaker cable and connectors piling on which shrinks those glossy numbers back by a decimal or more. Gush factor meanwhile isn't an accepted audio term. Hence it's nothing designers measure for. Meanwhile impulse response, slew rate, frequency response, total harmonic distortion…  these and others are standard terms, thus ways to measure and look at the behavior of audio circuits and transducers. It just leaves consumer to wonder. How do all of those figures and terms relate to goose bumps, to absentee listener fatigue, to emotional involvement, to PRaT, to vividness and any other subjective reason why consumers not recording professionals do upscale playback in the first place? If lowest measurable distortion were king, Halcro of yore should have been far more popular.

Only the two upper components on the sidewall rack were in the first signal path. The Aqua LaScala and Denafrips Terminator DACs sat idly by since they lacked onboard attenuation for the most direct connection.

In my listening impressions then, I couldn't cull from the tech vocabulary. Except for raw HF bandwidth, modern class D already tends to measure well. Purifi now add superior numbers atop that game. But again, what do those numbers actually tell us? As always, I'll have to use 'soft' terms and more poetic phrases to describe how the sound related to my own very subjective listening experience, not how an oscilloscope would look at it.

Reshuffle. The first session had the Purifi amplifier sound overly relaxed, mellow and a bit monochromatic. This behavior reminded me of the difference which insufficient or no gain can make between a pure passive and a superior active preamp like Gryphon's Zena just in for review. The interrelated qualities of drive, presence, robustness and materialism compromise. Now music's innate tension or energy fails to transmit and communicate. It presents as too languid. This wasn't at all shared by the Nord monos. To eliminate an unfair Danish handicap of no buffer versus what for home use are long interconnects—in pro terms they're still an absolute trifle—I repositioned the two source components onto a mono amp platform. This kept the Allnic balanced cable to 1m. But as it should have considering the D1's proper output stage, the improvement was mild at best. To compare apples, I really had to activate Purifi's buffer. Eight jumpers and six small hex bolts later, that case was closed and the real game afoot.

In theory, unnecessary gain that's burnt off resistively by your volume control is pure excess. You generate something only to throw it away again. If your loudest listening only hits 7:00 on the attenuator, that's the very definition of excess. But if more gain only backs off your attenuator from 16:00 to 11:30 yet sounds demonstrably better, I'd call that gain far from unnecessary. Following that logic, all of my sessions past the first thus used the extra 13dB introduced by activating Purifi's own buffer.

Second impressions. This sound was completely free from any exhibitionist explicitness of the detail-über-alles school. That slices and dices detail like a flamboyant TV chef who shows off his high-speed julienne technique in closeup. The bass was blessedly free of that cyborg gestalt which converts a redolent acoustic upright and percussion into hyper-damped synthetic bass and robotic drum machines. As such also the vital upper bass lacked that signature dry-yet-pinched feel to instead be properly rotund and texturally generous. The sound also missed any and all edge pixilation and surface gloss, the latter a routine artifact of excess airiness. Finally musical phrasing or flow wasn't hampered by even remnants of mechanical rigidity.

I deliberately placed my first descriptions in the negative. That shows what the sound was not to clearly isolate it from typical class D preconceptions. Many of those of aren't based on bad intel but actual albeit often earlier examples of the breed. Ticking off the 'anti' boxes now leads us straight to what the sound really was: exceptionally easy and easeful, very relaxed, subtly warm yet dry, naturally matte not shiny like an Apple retina display, nicely dense and properly fleshy. Those last two aspects scaled up to an unusual degree under higher SPL. The full measure of all that was a very natural balanced presentation without any sensationalist or flashy aspects which over time wear thin and stand out as artifice like collagen lips. Whatever advances Purifi's dream team had pursued relative to superior measured class D performance actually correlated with sounding more natural (and not just measuring better). That's key. Their tech wouldn't seem to pursue specmanship for its own sake even though promotional materials certainly should include some chest-thumping pride over better specs.

My first buffered sessions concluded that the Purifi tech was really in the service of a more natural sound. Though extremist 'philes will miss the message when phrased in such casual fashion, the Purifi amp demonstrated easy listening at a very high level. This meant that I could enjoy certain very personal guilty pleasures like Wael Jassar's Fi Hadret El Mahboub album. Its over-produced Pop gloss, excess reverb and compression all score entirely the wrong points on certain overly explicit gear. With the Purifi amp, this music was perfectly enjoyable despite its many technical flaws. To my mind, this amp then struck an ideal very practical balance. It didn't turn 90% of my music-first library into rejects because its production values aren't up to purist par.