The Tube Sound on the Avantgardes
Does the Butler sound like a tube amp? In certain regards, absolutely. But it also does certain obvious things differently. Does it sound like any SET I'm familiar with? Not. Does it sound like a high-power push/pull valve amp? Close. Like the Baron I used to sell, helped market and owned as my first serious valve component, the Butler is massively powerful. This translates as mondo image density and drive. You'd know this amp has big horse power under its hood even from behind a curtain. No matter what you play, there's constant pressure behind the music that propels it into the room. A decent way of describing this action is the fantastic image of a race car at full RPMs, active wheels spinning inches suspended above the tarmac, ready to surge forward once it's released on the pavement. Imagine this without any sound attached to the car's engine - just the tacit knowledge that once it touches the ground, the beast will take off without gradual acceleration or any need to throw any gears. It's just instantaneous full-blast-outa-here massive-attack glory.

The reason the Butler doesn't sound like an SET? It's got a kind of muscular tension inside the slightly thickened musical fabric that I don't hear with single-endeds. Call it ballsiness, beefiness or a constant state of charged readiness if you will. The extended soundstage width and the unwavering impression of mass and rock-steady solidity all telegraph push/pull while the image density suggests balanced electrical power. The presence of valves is most obvious in the treble which completely lacks the usual telltale transistor signs. It's less overt in the vocal range when compared to zero NFB SETs that create that peculiar heightened 3-dimensional 'pop'. The sheer displacement and grip in the bass of the Butler is something that eludes most SETs nearly by definition but can be achieved with something like a big Rogue or VTL. Here too the presence of valves might elicit a knowing after-the-fact "I thought so" because the bass avoids the hyped leading-edge brutality of certain high-current high-power sand amps. However, that antidote isn't exclusive to tubes by any stretch.

Where things sound more unequivocally hollow than solid-state again is in the overall dimensionality and layering of the soundstage. In my limited experience at least, that seems to elude sand amps as a species. Overall, I'd call the Butler TDB 2250 a rare balance of attributes from the two old camps. It creates a certain middle-ground position which also holds true for the earlier-mentioned Bel Canto eVo 4 GenII, albeit differently. The BCD is exceptionally articulate and precise. It communicates a sensation of speed, with the treble crystalline and extended but without warmth there or in the midrange. Avoiding even the faintest notions of syrupy or ponderous, the Butler is warm and -- there is that word again -- massive and dense. It definitely doesn't operate in the lit-up, accelerated, incisive and lean realm of OTLs for which, conceptually, it could be mistaken if you were just thinking tubes and zero output transformer.

Ultra-low bass on ambient albums seemed to diverge just a bit from even well-endowed p/p tube amps in that there wasn't even a subliminal loosening of grip and knuckles, just grunt and moxy as low as my room and speakers would support. Based on the old head-in-the-horns test which noted no noise on the midrange horn at all and just a mild amount of tweeter hiss completely normal with 103dB speakers, I'd have to call the S/N ratio of the Butler better than that of most all comparably powered conventional tube amps with their concomitant 'dither' of output tube microphonics. The resultant slight fuzziness endemic to most multi-paralleled valve amps is completely MIA in the Butler. It's perhaps one of the reasons why it doesn't telegraph that certain lush romance which, let's call a spade a spade, is a combination of 2nd-order distortion plus noise and a reason why most such tube amps get seriously red faced on an honest test bench.

The Butler deliberately doesn't go into microphonlandia nor deep into 2nd-order THD either. While it's thus mostly and in general like a high-power push/pull valve amp for the sake of comparative argument, it diverges from the common recipe by being cleaner and more articulate than the overall breed. And might I add that to get 250 watts of ultra-quiet full-on tube power would usually set you back a lot deeper into hock than what Butler Audio wants for their amp? And that it would entail bias drift, tube replacements and centigrades of heat? And that by the time we're talking 800 watts into 8 ohms (of which the Butler is fully capable with the simple flick of the mono switch and which our own Chip Stern shall investigate when he gets my review loaner to augment the one he already has), the TDB 2250 is pretty much on its own and without competition?

Feeling confident that my hornspeaker interlude had revealed the essential sonic nature of our review subject when barely moved out of 'park', I now inserted the Gallo Reference 3s as examples of passive full-range speakers in the 88dB sensitivity range that would run the amp deeper into its power band and higher up its torque curve.

The Tube Sound on the Gallos
The essential "Butler Sound" transferred seamlessly to the Ref3s but changed in one important regard: The amp stripped pounds and sounded faster, like running in a lower gear and at higher RPMs. By itself, that perhaps wasn't entirely surprising. But another aspect did come as somewhat of a shock. I can already hear Vlad-the-Impaler aka Clip the Stern laugh the evil laugh of his "more power isn't always necessary but always welcome" bit. To wit, the raw heft and oomph the Gallos' 10" woofers pounded out from their puny housings was positively staggering. While running them with the optional bass amp those many moons ago had sharpened the leading edges besides adding extension and weight, I'd now estimate that the Butler by its lonesome got about 75% of the way to active Gallo drive in the heft if not attack department.

In fact, now that I'm thinking about it, even that shouldn't have come as a true surprise. Anthony Gallo had told me long ago that his Reference 3s love current. They don't need a lot of power per se -- even the 8-watt MiniMax amp can apply and surprise you -- but they really wake up when they receive a goodly dose of current such as tube amps can't deliver. Well, this tube amp can. Hearing it in action on speakers that thrive on this type of diet was a rare thing of booty to behold.

If I thought the Butler was a good amp on the Avantgardes, I now thought it positively brilliant on the Gallos. It still had mass and impact galore but had gotten truly fleet of foot with this pairing. It now had whomp and sting at the same time. If I thought the soundstaging on the Duos was good, the spooky holography central that is the Ref3s now kicked things up another notch. Examples of the former sting/whomp were in abundant supply on any of Renaud Garcia Fons' albums where the Frenchman with the monster bass growls and rumbles, saws and sings, rips and hammers. The spiccato interludes of bow flickering like a bouncing acid blur atop the strings had proper attack and bite for rapid machine-gun staccatos. The bowed descents into the depths were rich, sonorous and vibrant. The deep drums just dished out whoppie-ass and energized the room. In short, the amp's excitement factor had alighted when asked to put out a decent rather than barely-there amount of juice.

If asked to pigeon-hole it now in some category, I'd take one of its four feet out of the earlier push/pull drawer and stick it into the single-ended one due to the enhancement in openness, speed and textural relaxation. I hope you appreciate the foolhardiness of any such categorizations. Still, they can be helpful for an initial fix on a component. Delineate the overall map into sectors, draw the component's footprint such that it covers the various territories of which it contains elements. In this vein, I'd call the Butler Audio TDB 2250 3/4 push/pull for heft, density and soundstage size and 1/4 SET for immediacy and thereness. In the sand/glass equation, I'd call it closer to 50:50 but weighted such as to grab the good halves of either camp and reject their weaker ones. Because it avoids the lack of dimensionality and textural thinness of certain transistor amps, it doesn't say "solid-state" when you close your eyes. Because it avoids excessive bloom, midrange focus, hooded highs and bleary-eyed bass, it doesn't say "tube" either. At the end of the day and into a load like the Gallos, it's simply an amp that sounds very powerful but at the same time refined and warm without drag or any kind of rhythmic indecision. And though I don't suffer from tinnitus, the top end is definitely tube by avoiding glassiness, hardness and etchiness. Alas, it's not compromised in extension. Is it really "pure tube" then? See the conundrum?

Confession Time
If I could, I'd swear off tube amps in a heartbeat. I resent never knowing how far below par they may have gone since their aging is such a slow and insidious process. I resent all manner of things about tubes - but since they simply sound better, whatcha gonna do? You shut up and put up. The day Eduardo de Lima of Audiopax decides to try his hands on a solid-state amp, I'd be all ears since he's a friend of high-efficiency speakers and amps designed to get it up with them.

In the meantime, the Butler amp is here and primed and perhaps the closest friend yet for tubephobics who want all the gain but no pain. And yes, you should ultimately pair the 2250 with loudspeakers who can make at least partial use of its 250 watts on tap, either because your speaks or your hearing are inefficient; because your room is humongous; or all of the above for a happy party. And while I can't see a market for such an animal, I for one would be damn curious what a single-ended TDB amp of 15-35wpc would sound like. In fact, I'm hoping that despite its rarity and 100 watts, B.K. will eventually let me take his A100 for a spin should a loaner for clueless reviewers ever become available.

By way of explaining why my sonic descriptions are less itemized than usual, I promised Chip a tag-team effort on today's assignment. I want to leave room for the Chipster to fill in the blanks while spinning off parallels to the mighty McCormack DNA-500 and becoming one of -- if not the -- first US listener to groove to two Butler 2250s running in full-steam 800-watt mono glory. Those readers who've eyed Mr. Butler's technical explanations with ill-disguised I-ain't-buying-this rejection should know that I've run it past two audio engineers. They both felt that while certain details in the explanations were naturally missing for the obvious reasons, the science involved seems to be solid and unique in its implementation. The patent pretty much indicates as much, too. But that's for techno weenies to worry about. I can tell you without hesitation that this amp works like a charm. As far I'm concerned, that's really all that matters in the end. And
did I mention that tubes in cool blue really do look very - er, cool? Just imagine, a tube-sounding amp whose two small-signal tubes may never age for as long as you own it so that your sound doesn't go adrift over time. Just imagine, a tube-sounding amp with very high power and honest current delivery. Now that's something to write home about. Hear hear, here here! Perhaps B.K.'s White Paper is truly lily-white after all - and all of it? Chip, your turn...
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