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Positive Feedback ISSUE 6
aria audio WT100 XL LS stereo amplifier
as reviewed by Art Shapiro
Though I lived with an Aria WT100 amplifier for a couple of months, it will be unusually difficult to properly convey my reactions to it, as the experience was quite complicated. For readers unfamiliar with the Aria name, it represents the latest work of Michael Elliot, well known in audio circles as the guru of the now-defunct Counterpoint brand. This hybrid amplifier looks different than any audio product I've previously encountered. It might be described as resembling an upscale air purifier. The roughly 16.5 by 8 by 12 inch tall unit is undeniably attractive, with silver louvered side panels bolted around a gold-tinted chassis. Removing the louvered front panel gives easy access to the two tubes. The WT100 is solidly constructed, giving an assurance of quality and stability. The reviewing sample had various premium high-quality passive parts installed in the circuit, an extra-cost option.
I had some quibbles with the ergonomics. There are two pairs of speaker binding posts for each channel to facilitate bi-wiring, and those eight jacks span the width of the rear panel. After seeing the user-friendly designs for speaker cable attachment in a number of amplifiers that have passed through my system, I am less and less enamored of closely spaced connectors, even those of as high quality as the gleaming gold-plated ones on the Aria. One nice touch, however, is that the jacks are mounted on a beveled panel which angles them toward the user. This greatly improved access to them, but the main power switch is directly behind the inner two pairs of connectors, and it was quite difficult to get a finger between my massive Cardas cables in order to activate the switch. If the amp were in a cabinet or a rack, it might be nearly impossible to reach it. RCA input jacks were conveniently positioned at the outer edges of the rear panel. XLR jacks (not appropriate for my system) were located just inside the RCAs.
The main power switch puts the amplifier into standby mode, indicated by an LED on the front. Unfortunately, the LED is obscured by the louvers unless the amplifier is at eye level. When the switch is depressed, the LED alternates between blue and red for close to a minute, and then glows blue to indicate that the unit is ready for use. Several orange lamps on the main circuit board give an attractive glow to the unit when it is in active mode, although the lamps are not very visible in daylight or in a brightly lit room. Four Zobel networks were supplied with the amplifier, and I was instructed to use two on each bi-wired speaker. I did not use my subwoofer during my time with the Aria, not wanting the sub's built-in amplifier to affect my evaluation. Several sets of tubes were supplied with the amplifier; some NOS Sylvanias provided the best musical balance.
My initial days with the amplifier were less than stellar, to put it politely. The sound was remarkably lifeless and unexciting. I communicated my concerns to the editor, suggesting that this obviously high-quality product seemed to be so incompatible with my speakers as to be unusable. The information was passed to Mr. Elliot, and we had a very pleasant exchange of e-mails. I explained how demanding the huge Concert Grands were of amplification. Despite their high efficiency, the more power one throws at them, the better they sound, and it might be a simple matter of inadequate wattage from the Aria. Michael suggested that things might not be as dire as I thought. Recent changes had been made to the circuitry of the Aria, having to do with its overall stability. He suggested that I might want to give the revised unit a chance, and that it would also involve discarding the Zobel networks. This did not require any great effort on my part, so I was happy to see what the improved amplifier might do. Sure enough, upon pedaling home from work one day, I was pleased to find Dai, an Aria engineer, waiting in my driveway. I played a couple of tracks from a Sony sampler I often use in my reviews, one of Dietrich Fischer-Dieskau singing music by Mahler and one of Vladimir Horowitz playing a Chopin polonaise. Playing the same music on both amplifiers, he could not deny that the Aria was being whomped by the Music Reference. Away went the Aria, and a couple of days later, a car pulled into the driveway and it was back. Not even staying to hear the revised product, Dai told me to pull the Zobel networks and enjoy the amplifier, and away he drove.
There was no question that the unit had been improved. The sound had substantially more body and impact, better dynamics, and a more realistic tonality. I still didn't find it as enjoyable as my RM9, but at least the situation was not as preposterous as before. A few more e-mails resulted in Michael Elliot himself coming to hear the system, with the understanding that sonic fine-tuning of the amplifier could be done on site by means of minor modifications to the circuitry. Michael agreed that the Aria wasn't sounding up to snuff, and started poking around my system. He quickly realized that I had both amplifiers hooked up at the same time, one to each of the CAT's two outputs, and suggested that this was Not a Good Thing. I explained that only one would be powered up at any time, and that there should be no effect from the amp that was turned off. He explained that impedance issues, even from a powered-down amplifier, could affect the sound, so I pulled the cables from the RM9.
We powered up the Aria to hear the effect of the RM9's removal, and were greeted with a huge amount of hum, primarily from one channel. The next hour was spent in a desperate attempt to figure out what was going on. We moved power cords amongst the dedicated outlets. We swapped interconnects. We pulled out my old Kora DAC. All for nought. We reconnected the RM9, still powered down, and the hum vanished. Then became clear that I had a grounding issue, and that the RM9 was somehow serving as the system ground. We pulled the RM9, and I got a length of ordinary hookup wire and attached one end to a banana plug that was sitting on the rug. The banana was jammed into the grounding hole of an unused electric outlet, and the other end attached to the grounding screw on my CAT preamp. Voila! The hum was gone, and we could concentrate on the revamped Aria.
Michael was correct. The sound of the Aria unquestionably improved. We played several selections, including the previously-mentioned Mahler and Chopin tracks. He concurred with my assessment that the sound was still a little lightweight, and suggested that it was time to make adjustments to the Aria's circuitry. The louvered panels and top were removed from the chassis, exposing the guts. The operation involved replacement of several pairs of resistors, which had the effect of altering the power going to the pre-driver and driver stages. Michael explained that the amplifier would measure the same but that its overall sonic characteristics would change. He decided on a specific set of resistor values that he felt would provide optimal sound, and Dai went to work. Interestingly, to facilitate the process, the resistors were suspended several inches above the circuit board on stiff wire risers. In a normal unit, they would be directly on the circuit board along with all the other componentry. A few minutes later, after a frustrating search for a screw that had disappeared into the nether regions of the amplifier, the changes were complete.
Sure enough, there were obvious changes to the sonic signature of the Aria. It was somewhat warmer and richer than before, a desirable improvement. The sense of power and sonic impact was better than before, if not stellar. The speed of the amplifier had been slightly sacrificed, but not to an obtrusive degree. It was as if a lightning-fast welterweight had moved up in class to a respectable middleweight. Michael agreed that the Aria now sounded a lot more appropriate for my system. He was slightly concerned that he had perhaps overdone the transition by a tiny bit, but believed that what I had was well within the bounds of reason. I also learned that this fine-tuning could be done at no charge at the time of construction, based on discussions with the individual customer and his or her sonic requirements. After the fact, the customization would be a purchased service. I would be hard-pressed to complain about such a customer-oriented company. The ability to diddle a product's sonic characteristics is not typical of the audio industry.
I had several weeks to listen to the custom-tailored amplifier in my system. My remaining observations are based on the modified unit. At the opening of this review, I mentioned that I expected to have difficulties conveying my impressions of the Aria amplifier. Why? Normally I try to describe my impressions of a product by describing what I hear on diverse, although primarily "classical" selections, noting how it differs from what I normally use, then try to sum up the observations with an overall assessment. For the Aria, however, this routine will be broken in an effort to emphasize a point, and if this point isn't stressed right off the bat, it will appear that I'm condemning what in reality is a very fine product.
My fellow PFO reviewer Mark Katz, a frequent visitor to my home, has already reviewed the Aria, and I've avoided looking at that review to avoid influencing my own thoughts. We usually chat on the phone each evening. The following conversation, slightly reworded for the sake of clarity, transpired several times in the last couple of weeks, and I think it will be more illustrative to the reader than any musical specific examples I could present:
Art: "I'm having a really tough time with the Aria review, and the Editor is starting to twist the thumbscrews."
Mark: "That's because you really prefer your RM-9, right?"
"Yes, but that almost automatically will make the reader think that the Aria is not a worthwhile amplifier, and that just isn't the impression I want to impart."
"Well, consider the specifics. Does the Aria have better tonality?"
"Better control in the bass?"
"Better extension at the frequency extremes?"
"Better bass slam?"
"Can you think of a single sonic attribute in which you would say that the Aria is as good or better than your RM9?"
"No, but the odd thing is that it's relatively close in every one. They really have similar sonic signatures. There are times where I've just wanted to enjoy some music without worrying about the review, and I've used the Aria and been completely happy. It's really a nice amplifier, and it isn't intimidated by the huge multi-driver Concert Grands."
"You're rightthey do sound remarkably similar, and here's the thing you refuse to admit to yourself. You keep looking at the RM9 as a marginally acceptable, stopgap amplifier until you can somehow scrape up the funds for some massive monoblocks. We both know that the more power your feed your Concert Grands, the more glorious the sound becomes, but you're talking huge bucks to better what you already have. You've had an awful lot of equipment pass through your system, and the RM9 has been the best you've heard for something that's affordable.' It sounds better in your system than you realize, and it's still quite an expensive amplifierit costs more than most folks spend on their entire systems. For the Aria to be merely edged out by the RM9 is still indicative of the WT100 being a superlative piece of equipment."
"I can't argue with you, but will the readers be able to discern just how good an amplifier it is?"
"We can only describe what we hear. Remember that the Aria is something like $6K. Your RM9 went out of production because Roger Modjeski's parts costs soared over the years, and if it were to be made today it would probably cost at least what the Aria costs, possibly more. If the reader realizes how we're talking relatively modest differences in an extremely demanding system, then it should be apparent that we're talking about two first-rate amplifiers."
"Death, where is thy sting?"
Mark is right, of course. In a different system, with different electronics and different speakers, I'd be willing to bet that the two amplifiers would continue to sound surprisingly similar, and that my preference might be different. The Aria is a terrific amplifier. Let's look at a few specifics. The great majority of my personal listening is to solo piano. I'd recently been playing a CD on Lyrinx of the unfamiliar pianist Vanessa Wagner playing music of Rachmaninoff. I concentrated on the third movement of the Second Sonata, which, for those of you unfamiliar with the work, has some brief lyrical sections, with the remainder being a torrent of sound, with so many notes that the publisher could save money by using black paper and merely printing the white spaces around the notes. The lowest notes of the piano seemed a touch more obvious on the Aria, but as the music got faster and more complex, the RM9 edged out the Aria. It was a little bit clearer without being brittle, and slightly more open or spacious. The grand piano seemed a touch grander through the RM9. When the piece entered slower, more melodic and less pyrotechnic passages, I could appreciate both amplifiers.
I then turned to an unusual Marco Polo disc of Daniel Bluenthal and Robert Groslot playing Debussy two-piano transcriptions of other composers' orchestral works. I selected a performance of the Saint-SaŽns Introduction and Rondo Cappricioso, a work less massive than the Rachmaninoff but similarly encompassing the entire breadth of pianistic technique, from the lyrically melodic to extreme runs over the entire keyboard. First connecting the Aria, I could appreciate the rich, warm, roundness of tone in the slow introduction. In the hair-raising sections of the work, the Aria presented the torrent of notes relatively cleanly, with an appropriate harmonic richness. There was an appropriate delicacy and "plinkiness" to the upper extremes of the keyboard. Through the RM9, I was better able to appreciate the separation between the two pianos, and also sensed that I had a little more insight into the complex piano waveforms. As with the Rachmaninoff sonata, the RM9 was a tad clearer in the fastest piano runs, with perhaps a little more percussive impact at the treble end. The music seemed to sing a little bit more.
I decided to try a big orchestral work, so I selected a Chandos CD of the music of Sir Edward Elgar with Alexander Gibson conducting the Scottish National Orchestra. I chose one of my favorite Elgar pieces, the 4th Pomp and Circumstance, not the famous one. The bass foundation seemed slightly less controlled through the Aria, although scarcely to a significant degree. As I went back and forth between the two amplifiers, the complex harmonic texture of the orchestra seemed to resolve itself just a little more appropriately through the RM9, perhaps due to its being a tiny bit clearer. Hearing the Pomp and Circumstance through the RM9 made me almost want to turn off the system and go out and purchase a big flagpole and Union Jack for the front yard.
Going to the opposite extreme, I pulled out a gorgeous viola recital entitled Beau Soir, with Hafrtmut Lindemann performing on the German audiophile Tacet label. I chose the title piece, by Debussy, a gentle and melodic piece with piano accompaniment. Differences were even less pronounced than with the more complex selections. The viola possessed a slightly better singing quality through the RM9, with superior ambience and openness of sound, but it was fairly subtle. I might not be aware of a difference if someone were to sneak in and switch amplifiers while I wasn't looking.
For a vocal selection, I selected the gospel CD, Standing in the Safety Zone by the Fairfield Four, on Warner Brothers. I played the song "Roll Jordan Roll" through both amplifiers, and didn't have much of a preference. The Aria was a tad warmer than the Music Reference, and blended the male voices in a particularly appealing manner. Through the RM9, the tenor vocalist may have been a touch sweeter, and the sound spread slightly further side to side. It would take a harsher critic than myself to fault either amplifier, and the engaging performance could be appreciated with either unit.
Further musical references will not be illustrative. Let me reiterate that the Aria is a solid performer, and gives the impression of being a high-quality, reliable product. After the onsite modifications, its sonic characteristics were surprisingly similar to those of my own amplifier, though just a smidgeon warmer. It couldn't better the RM9 in this particular system, but was close enough that listening was always a pleasure. From a pragmatic standpoint, getting such gratifying performance from a hybrid amplifier is a real plus, as the owner need only worry about two tubes rather than the even dozen in my RM9. It isn't an inexpensive product, but audiophiles able to play at that price point should be aware of the Aria. I've enjoyed my weeks with the Aria WT100, and will be sorry to see it depart. Art Shapiro
WT100 XL LS stereo amplifier