Build quality, like Rolls-Royce, is adequate for the task

No discussion of the WT100 XL Aria amplifier would be complete without commenting on its stellar construction. Even internally it flaunts distinctive architectural elements that are seemingly designed to withstand unthinkable structural stresses.

Where do we start ogling? How about those four massive Super-Through capacitors (to left) suspended inside a felt-collared aluminum brace that itself is bolted to the solid aluminum machined grated side panels and uses strategically placed through holes for the flying leads hookup wire?

Or the beautifully laid-out bipolar output stage to the right, with its localized chimney-style heat sinks and substantial circuit board buffered on rubberized standoffs?

Did I mention four pairs of top-line Cardas binding posts for discreet biwiring? XLR shortening plugs to prevent open circuit noise contamination if the single-ended inputs are used?

Or the threaded spike option to replace the five bottom panel rubber bumpers if so desired? How about cryogenic treatment to critical parts and the premium valves, precise selection of which is part of the XL package deal (more details below)?

From the pictures, you already have a solid impression of the WT's splendid outerwear in softly brushed champagne and silver, with a power LED ensconced by the front cover that lights up red for standby (main rear panel power switch on, frontal curved slice switch depressed), blinks purple while the main voltage ramps up (frontal switch engaged) and settles to blue once the internal relay clicks to signify that the input tubes are now fully fired up.

The modular construction of the WT reminded me only conceptually of the industrial Nelson Pass Aleph 3 of yore. It bolted together 45-degree mitered heatsinks with a predetermined gap on all four sides. Instead of bristling heatsinks, Aria Audio uses smooth champagne-colored quarter-height solid panels with a centrally recessed "pinstripe" channel for the concealed transformer base.

The signature grated panels above the base (save for the rear panel which is solid) make up the side walls on top of which floats a solid roof plate with rounded corners. The gold and silver side and front panels feature the same 45-degree miter cuts as the porcupine Pass, with an equally predetermined gap on the grated panels, and a smaller one on the solid ones.

Especially with low ambient lighting, this powered-up house of sound is a veritable stunner. It could take pride of place in a miniaturized cosmopolitan skyline of highrisers, lit up from within not only by the tubes but also a bank of orange diodes that cast a warm romantic glow through the amp's "opened blinds". Together with the tasteful blue power indicator, this additive radiance transforms the amp's tremendous sonic solidity into a visual counterpoint of ephemeral airiness.

Tea and crumpets, Sir?

As part of the $5,700 premium upcharge of the XL version ($10,199) versus the stock ($4,499 Internet-direct), Michael Elliott not only personally builds, tunes and play-tests the amps but also delivers, installs and voices them in US and European customers' homes (certain restrictions may apply). For $8,800, the XL amp is available factory-direct and -- minding "translational" errors of shared musical descriptors -- pre-voiced in concert with stated preferences. The amp's voicing can be factory adjusted for a labor fee of $280 thereafter, or Michael Elliott can perform it onsite for the original differential of $1,399.

Here, let me help ya - ligament-rippin' flexibility

Due to the noise-sensitive >103dB efficiency of my reference Avantgarde DUO hornspeakers, I had requested the LS low-sensitivity version that sports an impressive 96dB signal-to-noise spec. This amp requires a stout 4V RMS input for full output. To put into perspective how this translated with my reference Bel Canto Design PRe1: Aria Audio's 100wpc design occupied the 80 range on its 0.5dB-step volume readout while the puny 6wpc Art Audio PX-25 frolicked in the 50 range. (Btw, the PRe1 has been superseded by the PRe6, sporting added channels, upgraded volume control chip, onboard phono stage and a projected retail of ca. $3,800.)

The PRe1's unity gain is at 84, with 16dB of gain to 100 above and signal attenuation below. Though 16 times more powerful, the Aria amp's gain structure required 30dB more signal strength to achieve equivalent output levels with my micro-power though high-gain SETamp.

This is no mistake but fully deliberate. You see, most tube preamplifiers output 4 volts or more. With a standard-sensitivity amp, this allows frustratingly little useful volume range before things go from too quiet to too loud. Add high-efficiency speakers, and 7:30 o'clock on your dial could equate thunderous runway noise pollution. Hence, the 17dB low-gain LS version with 6SN7s.

The 26dB high-gain HS version needs only 0.6V RMS for full output, is optimized for the gain structure of most solid-state preamps and uses 6SL7s instead. Hi/lo conversion is not quite as simple as swapping tubes but requires resistor changes. If a change after purchase is desired, the factory can perform the modification.

Need more brawn rather than more sensitivity, you dinosaur brute you? Write another check, then pop the hood, flick the stereo/mono switch and pay attention to how you rewire the speaker leads (incidentally, the rear panel's comprehensive silk screen legend makes this a foolproof undertaking). Presto, 350w on tap, 500 into 4 ohms. Seeing that you're presently on-line, it seems redundant to copy further specs already comprehensively detailed on the manufacturer's website - click here for the lowdown on the WT100.

Painless conclusions

Michael Elliott's prior claim that his bipolar output stage remains utterly transparent to the particular sonic envelope of the preceding tube turned out to be stunningly accurate - what you hear are the tubes, not the transistors. This results in a device that sonically needs to be thought of as a zero feedback push-pull vacuum tube amplifier. It goes places precious few conventional tube amps could: Negligible output impedance, 1Hz to 120kHz bandwidth, high current delivery, unconditional 2-ohm stability, 100/350w of power that nearly doubles into 4 ohms - and all that without a sweating forest of valves and the (under high-power conditions likely) potential for sparkly power tube failures.

from left to right: Philips black-base JAN 6SN7WGTA; Sylvania VT-231; red-base RCA 5692 - just a few tantalizing choices.
In a very real sense then, this hybrid design truly does combine the best of both worlds. To be sure, best is here bandied about somewhat loosely, and in a more general than absolutely literal sense. It does leave room to disagree on particulars - such as optimized low-power SET/high-efficiency speaker combinations like the ones I fancy. They offer their own very real and special virtues that, when executed properly, go beyond even this amp at least for this listener.

However - the ebullient everyman advantages of Aria's novel and rare hybrid solution are dead obvious: Bass control and sheer drive regardless of load impedance. Call it a tube amp for all seasons - er, speakers. Add inexpensive tube fishing in the mainstream to tweak the sound to your preferences. Outside the stout club fee required to enter these rarefied leagues of made-to-order objects -- with a parts pedigree that reads like a deluxe laundry list at the Trump Towers -- I really can't find any faults.

Consider too the crated and personal delivery, the excellent owner's manual, the unconditional 30-day in-home trial guarantee of the standard version. It all adds up to one very classy operation. Based on my personal encounter, I'm happy to recommend this amp for an intimate tête-à-tête to all tube lovers who, thus far in vain, have searched for that satin-gloved tank that will, Goddammit, command the respect and obeisance of their stubborn solid-state diet speakers without fail.

Does that describe you? Give Michael Elliott a call about a stock WT 100. For $4,499, you get what via traditional retail routes is really an $8,000 piece. If -- as its maker claims -- it does offer 85% of the performance of today's blue-blooded XL sibling, it's a slam dunk in its class.

Now, is the premium hand-delivered version worth the steep 126% price increase?

An unexpected response

Above: Manual; speaker cable resonance damping network (to ameliorate potential amplifier heat or hiss, not an issue with any of the speakers I tried); XLR socket shortening plugs when RCA inputs are to be used - the proper kit for the well-seasoned audiophile.

Ah, fellow pilgrim, most excellent question. As is my custom, I sent Michael Elliott the above verbatim review copy for fact-checking. He came back with a proposition. After due consideration, I accepted. As mentioned, part of the XL premium package includes not only personal delivery and setup but a degree of sonic custom voicing and system matching that's possibly unmatched in the industry. Upon reading my findings, Michael agreed that what I had described more or less reflects his personal sonic hierarchy. It thus constitutes the standard tuning of his circuit. Based on his experience, it satisfies about 90% of his clientele.

However, his hybrid architecture was conceived from the start with tuning flexibility in mind that's a function of adjusted parts values in critical junctions. It allows him to shift the voicing all the way from chocolatety-rich to "as light and airy as sunlight dancing on Aspen leaves and anywhere in-between". This individual tailoring of tonal balance is something he performs in the home of every XL customer who purchases the personal delivery from him.

Could he pop out to Taos and demonstrate this? His amp was indeed very capable of emphasizing those certain performance traits I had favored in the Art Audio PX-25 and Bel Canto eVo 200.4 . By extension, he perceived them as negative criticisms against his own offspring that could easily be rectified.

I ruminated but briefly. Said I yes, I could document the entire experience available to the prospective XL Aria customer. I'd take photos of the designer performing open-heart surgery on his creation. You, the reader, would be able to look over his shoulder and get a potent whiff of this deluxe service that could be yours if you lived in the US or Europe.

Also, I was curious about how Elliott would translate my requests for "a bit more top-end illumination", "a smidgen more microdynamic movement", "a tad more inner detail" without affecting any of the already really strong suits of the WT100.

After all, an amp doesn't use a crossover like a speaker. You can't simply turn on the tweeter a bit harder or shift a crossover point to induce a subtle emphasis elsewhere. Truly, to pull this off, Michael would have to demonstrate a highly artistic touch. One that knew how to translate subjective performance subtleties into the how & where of parts substitution. It'd turn his amp into a musical instrument, him into a master tuner.

Heck, all this had the makings of audio history. I only had to insist on one thing. My review stood as written, not a single word amended. It describes the sound of the amp as originally delivered. The post-operative findings, of the amp custom-calibrated to my room, my components and my personal biases, would become an addendum, an additional page.

Agreed - Mike wouldn't have it any other way. Now we were in business and he announced his arrival for 10 days later. Click "next" once more for that last virtual page flip of today's report. I guarantee you'll find it most worthwhile and enlightening.