In the main system, comparators were a Vinnie Rossi L2 Signature + Kinki THR-1 combo of direct-heated/coupled Elrog ER50 + lateral Exicon Mosfets; and Cen.Grand's mighty Silver Fox. For cloudy files, this chain begins with cascaded network switches and fibre optics between them. Once inside the 27" iMac, Audirvana Studio massages such data just as it does local files stored on a USB 3.0 4TB SSD. Once they exit the iMac via USB, there's a Singxer SU-6 super-cap powered USB bridge. It dispatches S/PDIF to a Cen.Grand DSDAC 1.0 Deluxe which resamples all PCM to DSD1'024 on the fly. Set to variable out, I built in 10dB of attenuation on its Muses-based analog variable-gain chip. On HifiMan's Susvara, this had Amethyste in low-Ω mode at ~13:00. Comparator amps were live simultaneously since both the Cen.Grand and Vinnie Rossi accept XLR inputs, Amethyste only RCA. Click an album covers to hear tracks.

Thinking folks could expect pentodes + push/pull bipolars versus single-ended triodes + Mosfets to populate a story board with the ancient feud between 3rd and 2nd harmonic distortion. With no listening whatsoever, a creative writers' room armed with that notion alone could get busy with an entire review season's plot line. And some of it—though rather less than expected—did factor. But first my desktop skirmish against the Enleum. Here the difference delta was deeper. Let's call Amethyste a VB Studio release from Warner Brother's younger sibling where 'v' abbreviates virile, vital and vivid, 'b' big, bodacious and brawny. With those six moons in alignment, tunes over the French exhibited more pressure, saturation and swagger. Particularly the bass held a fantastic twin-ace combo of wallop and wiriness. This informed the musical engine room. At stouter levels, PRaT cooked at a boil against Enleum's gentler simmer. Whilst the latter's €6'250 metal work upstaged Kallyste's in screwless fanciness, the French turned tables with transmitting more musical energy aka pop, crackle and snap. It's when dynamic fortitude, colour intensity and timing precision tee up. Inject higher wetness into this cocktail and without sacrificing resolution from a higher noise floor, Amethyste emerged the sonic victor. The AMP-23 played it more damped, dry and energetically subdued. On its own, I'd never call it any of that. It's in this particular A/B and for well more than twice the coin that the SoCal/South-Korean bonsai amp found itself overshadowed and outshone. Of course it also drives my speakers and slips tidily beneath my lazily curved 34" monitor screen. In my office Kallyste's bigger kit however would be homeless and my loudspeakers powerless.

In the big system meanwhile, my top-shelf battle played out perfectly parallel without a clear leader. Tonally/texturally Amethyste evinced a bit more 'pentode pungency' than the L2 Sig's 'triode treacle'. That sideways shift did suggest a subtly different distribution of mild low-order THD. Relatedly, the Kallyste was slightly more damped, the Vinnie Rossi/Kinki combo a touch more billowy. Textural elasticity relates directly to my general perception of direct-heated triodes. Here Amethyste gripped harder. On dimensional voluptuousness for a stronger hint of quasi holography where the French had overtaken Enleum with a clear lead, now both contenders felt even. Considering that the Vinnie Rossi demanded $17K when I reviewed it four years back whilst the Kinki added €700 when first released, there were no shekel shenanigans. Fiscal parity was the order of this very fine day. It set up burning personal curiosity about Kallyste's preamplitude.

First, let's extract the above's primary takeaway. With its hybrid approach of valves preceding transistors plus tube rectifiers to avoid power-supply switching noise, Amethyste sits between the classic polarities of pure transistor and tube circuits though in 2023, those lines are often blurred so outdated. For discussion purposes, these old-fashioned notions are simply still useful. With them we'd say that from the thermionic camp Amethyste appropriates more spatially acute soundstaging and saturated colour intensity, from the transistor camp punchy control, crunchy bass transients and high separation. My personal biases lean toward rhythmic adrenaline, emotive communicativeness and evolved depth layering. Underpinning it all should be a solid base of subjective speed. That means clarity and control to banish blur, fuzz and rhythmic laziness. It's an area which I don't feel glowing glass serves best. It's why my own SET adventures have long since stopped. I mention this because Amethyste wasn't guilty of any of it. Rhythmic urgency was keen not kaput. Suddenness factored not sedateness. So we might say that Pascal's musical trail mix only packed tubular goodies. Prospective personal valve failings like undue thickness, time blur and a textural softness which feels like artificial reverb injection from excess decays were MIA. Here Amethyste was properly athletic and punctual. By my count that places its tube/transistor balance quite ideally in the mythical middle. In his review, Cameron came to much the same conclusion. He then opined that for this daunting tariff, he'd rather have a more tube-sounding valve amp as well as a more solid-state-ish transistor amp. Personally I'd not want to veer any deeper into Tubelandia. I call Pascal's dosage and his extract's constituents perfect. The Cen.Grand Silver Fox plays it a bit darker and meatier than the Enleum. It roughly split the distance between the latter and my two tube-endowed contenders. Now we're ready to inspect Amethyste as preamp fronting two different speaker rigs. Neither of mine needs a preamp. Each DAC packs variable outputs. The upstairs Sonnet Pasithea executes it by making the reference voltage of its R2R ladders variable. As stated already, the downstairs Cen.Grand applies precision resistor ladders on a PGA chip. Both DACs can be set to volume bypass. So that's what I did.