Remembrance. When quite a while back I'd settled on PlatiMon's baby brother SuperMon Mini as the new upstairs speakers completed below 80Hz with the Dynaudio sub, I'd moved out my icOn Pro4. What replaced it was my older Vinnie Rossi L2 Signature active linestage. Its two direct-heated triodes run in a grounded-grid circuit which omits coupling caps and output transformers for a far more direct path. That also really explodes the bandwidth. The Mini's compound/isobaric 4" mid/woofers from Ted Jordan in their tiny rear-ported aluminium extrusion are very quick and open. In combination with a small AMT and my electronics, they erred ever so slightly on the side of brightness. I find that to benefit whisper sessions which won't white out due to the active sub in play. My favorite tubes for the L2 are Elrog ER50, a kind of 'super' 45. They injected minor tube textures to mellow the speakers just right. Now the bigger MTM array of PlatiMon equated to a 7-inch virtual coax. Returning to a Pál passive improved the sound over the premium valve preamp. I'd of course heard this before. But then speakers changed, the 4Pro benched and I forgot. Comparing my ultra-quiet ER50 to switched autoformers over these bigger monitor speakers, the magnetics were quicker on the transient uptake as though rise times had improved. They were more dynamic (!), more direct/open and more exciting yet stayed well clear of any wiriness or stridency. As Pál's client with the Allnic push/pull 300B transformer-coupled preamp had found a few pages ago, an icOn can hit the ball farther out of the park than you'd think. With that record set straight and reinstated, it was time to stir up some sibling rivalry.
That played out as PCM x DSD. My iFi iDSD Pro Signature can process PCM as PCM native or oversampled up to 768kHz; or it can resample PCM to DSD512/1'024. The above Cen.Grand DSDAC 1.0 Deluxe only resamples up to DSD1'024. Whilst my collection of native SACD/DSD is meagre, I do have some such .dff files compliments of a reader who gifted me with an SSD packed with his stack from which I copied my favorites. Against this background I conclude that PCM sounds more resolved, more treble lit, crisp, damped and spatially more separated/teased out. DSD presents softer and rounder, more muted in the treble—this aspect improves sharply past DSD256 but even at 1'024 still doesn't quite equal PCM—then spatially more billowy as though subtly reverb-enhanced. In different terminology, PCM's signature strikes me as more nearfield so all about direct sound's steep transients and related articulation; DSD more farfield so about reflected sound's enhanced textures, tonal sweetness and associated relaxation. That talks generalities for the purpose of being relatable. In those terms the icOn 4Pro played the PCM hand, the Pure the DSD ace.
Be it the brilliant guitar arpeggios of my favorite flamenco guitarist Antonio Rey or the slightly hoarse vocals of El Cigala on this gorgeous bolero, the Pure didn't seem to place its virtual microphone quite as close to either. That created a DSD-type slightly more decay-filled sound. New tones seemed to blend a bit more with prior tones still fading. Textures filled out a bit, separation toned down. Though not a large step change compared to what speaker or amplifier changes can cause, it was easily heard. Having for all of my audiophile life listened to PCM, I refer to myself as conditioned by it. As such, DSD strikes me as 'other' or 'colored' by contrast; a bit like the proverbial gilded patina of vintage photos. By implication, had I grown up in Japan around large classical/Jazz libraries of SACD discs, they'd have ear/brain-washed me instead. Now PCM/CD would out itself as the more prickly format by contrast. These aren't value judgements, just reactions based on being used to a particular sonic gestalt. If it's true that SACD gets far closer to vinyl than CD—I don't do vinyl so wouldn't know but the recent MoFi Gate plays to it—it factors that turntable amigos would prefer the Pure. As homo digitalus, my immediate allegiances were with the impure 4Pro. Equally true, I'd adjust to the Pure in a hurry and thereafter would forget all about the difference. I had a far harder time distinguishing between battery and switching power. If there was a difference, I'd peg it following the same distinction, albeit seriously more faded or faint so battery for DSD, SMPS for PCM. Imagine the possible bumper stickers; and how the vast majority of drivers behind you wouldn't have a clue what they meant. But I trust that to you, they make sense.
Functionally the only main offset I spotted was that the Pure reached mute in one skip from current volume to -99 whilst the 4Pro rapidly attenuated down to -99. True to Pál form, at the SPL I massaged, his Reed relays really did switch without any audible clicks. Pál for president? There goes another bumper sticker too obscure for general consumption. Back to sonics, ears more golden than mine could find the above differences more decisive because their hearing and/or system operates at higher magnification powers. Perhaps then even battery power might step forward to be counted? As for me, I'll happily keep using my 4Pro with its stock wall wart. Passive preamps inspire admirers, detractors and generic assumptions. Some believe that they do nothing so really get out of the way. Others believe that compared to actives they don't do enough to lose out on dynamics and tone weight. Magnetic passives differ from resistive types in their voltage-to-current conversion. They dispatch ever more current as voltages shrink. That seems to benefit low-level listening by avoiding or at least significantly delaying typical white-out. That's my word for how colors desaturate, gumption weakens and dynamic contrasts thin out as SPL drop. Magnetic passives are hifi whisperers. In my experience with various icOn models, they beat active circuits on speed, lucidity, dynamics especially in the all-important micro domain and general directness and startle factor. I call them the single-driver widebanders of the preamp domain. Like a Cube, Rethm or Voxativ, the rest of our tight-knit kit must welcome their immediacy to not require elsewhere blemish fixes. Now it could surprise that different autoformer passives still carry subtle signatures. I don't believe that they do absolutely nothing. The signal still travels down coils of wire and terminates in connectors. Choice of materials and the electrical behaviors they trigger remain influential. To my ears they simply editorialize less than circuits with active voltage-gain stages. Yet the remaining something they do still exhibits faintly different flavors.
About which: "Usually I like my products but this time I'm in love with the 5 and MatchMaker, even a bit proud. I think the 5 is a great step up from the popular 4Pro. I love the real-life presentation of the buffer with lower-inductance Slagleformers and ½dB steps across 83dB with tilt. I don't think I'll be able to better this control unit in the future. Later will still come a Balanced 5 with optional icOn Selector (extra 2 XLR + 3 RCA inputs with unbalanced-to-balanced conversion). And after seven years of my passive preamp period, then it will be time for something new and different."
