D1 & HPA. With ribbon tweeters weighing just 1/100th of a gram, I now employed treble excavators sans pareil. My attention felt like an expert grave robber who could track the lingering ghosts of the long dead. As expected, the Taiwanese deck converted this into an airier read of more exposed decay trails and venue halos around performers. Switching to the CanEver lowered the center of gravity into a meatier midband. It also widened dynamic range and, in direct opposition to the D1, changed its aerated pseudo dither embedded in the soundstage into a more damped presentation which felt even quieter because the same 'dither' was absent. This I laid at the feet of Mario's transformer coupling.

If we assign gloss values to tone textures as we would with paint skins, the D1 was the shinier and more reflective, the HPA the drier and more satin. With these Danish transducers groomed for ultimate speed, Mario's gains really magnified how high microdynamic ripples registered for more emphatic artistic inflections. Thinking about probable cause, I would point at his overbuilt power supplies of six versus two toroids. Lastly, the coordinates of the D1 emphasized soundstage depth whilst the HPA feathered things out wider.

I even had on hand the new Model One 4.7" two-way monitors from Cees Ruijtenberg's outfit Acelec. His new post-Metrum career also sees him helm Sonnet Digital whose next-gen R2R DAC cards will show up in active versions of these Acelec speakers as well as standalone converters. The Acelec I had was purely passive. Its rubber-bonded thick aluminium panels are lined with bitumen for very low mechanical noise. This prioritizes studio monitor linearity and high dynamics. Its transducers are Mundorf's folded 'ribbon' AMT previously seen in Gryphon's Mojo and Kaiser's Chiara; and a rear-ported ScanSpeak Revelator mid/woofer. On these compacts, Mario's extra dynamic headroom and greater meatiness dug deeper than the D1's starker more contained take. The obvious conclusion was that the faster and less voiced the speakers, the more preferred the HPA became.

Back to cans, Final's Sonorous X get often dissed for their high price, great weight and silver/gold bling. I just wonder how many dissenters have actually lived with them properly and with the appropriate fronting gear. Just because they're super sensitive doesn't mean any old portable player or ¼" receiver hole will fathom their true potential. To my ears and their undeniable weight notwithstanding, they're what Sennheiser's HD800 aspired to be but never were. With CanEver's digital volume, I had many precise small attenuation steps, so far better control and many more useful gradations than most analog pots which, on these headphones, tend to get too loud too quick. For self noise of Mario's circuit, I only had the very faintest steady-state hiss in the right channel. It was so low that I initially didn't even notice it.

Sonically the HPA continued its victory lap with flying colors rich and fleshy. Dynamics continued trigger happy. That caused more emphasis difference across melodic arcs, between rhythmic beats. In my book, these two qualities—higher dynamic contrast, more finely hued tone colors—are a must if one enjoys listening at lower levels. It's then that things naturally tend to flatten out and get paler. The keener a system is at keeping its finger on the 'dying pulse' of low-level dynamic flickers, the more it grips our interest. The longer it can maintain color density, the less we suffer the effects of intruding whitishness as though winter were coming. Particularly with headfi, long-term exposure to high SPL is fatiguing and dangerous. Listening lower will lengthen both our short- and long-term enjoyment of the hobby. Here Mario's weighting of the necessary qualities to make it so felt most apt.

Calculator time. For the very fair price asked, CanEver's Italian-built DAC/pre with transformer-coupled 'chip-direct' outputs plus amplified quad-transistor class A outputs with remote volume control plus high-output headphone sockets wins our award which accounts equally for fine build quality and lovely finishing. Informed by his love of old-school valve circuits with signal-path magnetics and big-iron power supplies, Mario CanEver's ZeroUno HPA contains no glowing filaments yet still manages to evoke refined core traits of such sonics for all the gain without any of the pain. If that's not a win/win, I don't know what is.

With Mario's permission, I'm hanging onto this review sample until the matching Olimpico stereo amp becomes available to then report on a complete CanEver system…