Luminous Audio Axiom II Walker-Mod version review

[jimtranr]

Executive Summary for Those Allergic to Prolix Reviews:

It’s magical.

Background:

Last June I posted a review of the $199 base version of the single-input/single-output Luminous Audio Technology Axiom II passive line stage, which replaced a conrad-johnson Sonographe SC25 active preamp in my bedroom audio system. In ordering the Axiom, I popped for an extra $25 to substitute a Caddock output resistor for the Holco included as standard in the unit. As the review noted, I was extremely pleased with the performance bump the Axiom provided, particularly in the areas of transparency and bottom-to-top as well as soundstage definition, with no sacrifice in bass response or dynamics, typically the weak spot of passives.

Over time the bedroom system has become the venue for serious listening, owing to time-sharing issues with video viewing in what’s supposed to be the “main” system. Accordingly, I’ve tweaked the bedroom system since the June 2017 review of the base-model Axiom by replacing the TEAC DAC’s stock power cord with an upgraded-connector Wireworld Electra 7 and the wall-to-power-conditioner Electra 5^2 with an identically-configured Electra 7, replacing the Uptone Audio Regen’s stock wall wart with an LPS-1 linear power supply, and mounting Stillpoints Ultra Minis under the source laptop, the DAC, and the LPS-1. (The Sonographe SA250 amp was already perched on three of them.)

Each tweak effected an improvement in causing the speakers to further “disappear”; in sharpening image definition and placement; in delineating soundstage breadth, depth, and palpability; and in deepening foundational impact and solidity as perceived from my position seated at the front edge of the bed with my ears at approximately at the apex of an equilateral triangle whose baseline is defined by the center-to-center distance between the speakers.

Could it get even better with an upgraded “Walker Mod” Axiom? For $499 I could get one with a 1%-precision-resistor-based 48-step attenuator (in place of the standard Alps Blue pot), Vampire CM2F/CB gold-flashed copper RCA input and output jacks (replacing the standard Axiom’s gold-over-brass jacks), 6/9’s silver internal wiring (versus 4/9’s), and vibration control in the form of internal case damping and four inverted-dome Sorbothane feet on the case bottom.



Curiosity is said to kill cats. Whether that’s true or not, it’s indisputable that it depletes audiophiles’ bank accounts. Mine, anyway. With the holiday credit plastic crunch behind me, I online-ordered a Walker Mod Axiom II, supplying the requested information on program-source voltage, amplifier input impedance (100KOhms in this instance), and manufacturer-spec’d speaker sensitivity to enable the unit to be configured for my system.

Listening:

When the new Axiom arrived early on a Monday afternoon, I installed it with the intention of letting it burn in for the recommended 72 hours with high-energy orchestral program on “repeat” in JRiver Media Center 22 before I gave it a serious listen. But upon noting that the final movement of Dmitri Shostakovich’s Piano Concerto #2 (Leonard Bernstein playing and conducting in a 24/352.8 Columbia remaster) was sitting in the JRiver queue from a listening session the day before with the standard Axiom, I said “what the heck” and clicked “Play” with the attenuator set at 11 o’clock.

“Piano tone.” My initial—and immediate--reaction. Lenny’s piano had sounded very good with the standard Axiom in place. Now I was hearing more body and timbral nuance. More on that later.

Since I have a life (read “yard maintenance, laundry, shopping errands, books to read, and a cat to feed, among other things”), I didn’t spend much time listening while the new Axiom burned in. But at around the 50-hour mark I decided to chill for the heck of it with a favorite piece—Randall Thompson’s Symphony #1 (James Sedares conducting the New Zealand Symphony Orchestra, Koch CD rip). I was just seconds into listening when I realized that all the superlatives I’d lavished on the Electra 7 upgrade to my DAC were, however justified, just prologue.

The already generous soundstage had broadened and deepened again. And its interior space had taken on an even more palpable, you-can-almost-swim-in-it presence. But while the visual illusion impressed me, it was the illumination and delineation of instrumental tonality and texture, the rendering of attack, sustain, and decay, the organic coherence of the ensemble, and the unmasking of inner-voicing microdynamics that had me shaking my head. Approvingly.

Fast forward to the 85-hour mark...and the piano again, this time in Leonard Bernstein’s Symphony #2, “The Age of Anxiety” (Bernstein conducting the New York Philharmonic, with Philippe Entremont at the piano in a 24/192 Columbia remaster). Impressed as I’d been with the rendering of the instrument via the base-version Axiom, I heard—as I had with the Shostakovich—an increased, spot-on fleshing out of keyboard tonality and hammer action.

To hear how the Walker-mod Axiom fares with female voice, I threw two tests at it: Sarah Vaughan’s live outing of Gershwin standards with Michael Tilson Thomas and the Los Angeles Philharmonic (“Gershwin Live”, CBS CD rip) and Frederica von Stade singing Lorenz Hart’s original unsanitized they’re-a-hoot lyrics for Richard Rodgers’ “Bewitched, Bothered, and Bewildered” (“My Funny Valentine”, with John McGlinn’s orchestra backing her up on an EMI CD rip).

The Vaughan was another case of an audition that bettered what I’d already considered an excellent presentation of Sarah’s vocal range and subtle nuance through the baseline Axiom. There was more gut-level “there” there down deep. And von Stade—an exception to the general perception that opera divas can’t “sell” pop tunes and may even struggle mightily with Broadway fare (some of you may recall that ill-considered DG “West Side Story”)—was point-sharp, in both image delineation and vocal articulation as she semi-coyly spun her saucy paean to “the laugh’s on me” pal Joey. In comparing the presentations of both recordings with the Walker-mod Axiom in place, the accompanying orchestra occupies a broader and deeper soundstage and a more persuasive spatial relationship to the vocalist, important in conveying the illusion of the listener “being there” at the performance.

I dipped into opera for the male-voice test, in this case Nicolai Ghiaurov singing Khan Konchak’s aria in Alexander Borodin’s “Prince Igor” (Emil Tchakarov conducting the Sofia Festival Orchestra, Sony CD rip). The aria is sung in Russian, so clear articulation is essential, and it’s delivered in spades with the Walker-mod Axiom. As with the Vaughan and von Stade recordings, the spatial relationships are also more clearly defined and, in the bargain, persuasive.

Operating Characteristics:

The attenuator’s operation is smooth, and the resistor values selected to populate it provide fine-gradation-from-step-to-step volume adjustments, with no need to hunt for something “in between”. I did my critical listening with the attenuator set between the 11 and 1:30 o’clock positions, depending on the level at which a given program source was recorded.

As I noted with the baseline Axiom, there is no perceived loss of either bass or dynamics with the Walker-mod unit. What goes in comes out. Channel tracking is precise, with soloists who belong at dead center rooted firmly there.

A remote version is available, and you’d think that a septuagenarian with an arthritic hip would snap it up. But I can use whatever exercise I can get, so that settles that.

Conclusion:

It stays.

Oh, what did I do with the baseline Axiom? It’s now in the home-office system, where it, too, constitutes an upgrade.