Electrocompaniet Classic AW-400M 400w Mono block amps (ea)

One of my favorite parental duties is dispensing advice that's calculated to make me sound wiser than I am. Among those pearls: Every so often you should change your point of view—your philosophies—just to see if your opinions can stand the strain. In doing so, you may discover a few things that are better than you expected them to be! 

I admit that, when I made up that nonsense, I had certain vegetables in mind. But late one night, when an unpleasant bout of thinking kept me awake, I realized that there are a great many older people, such as myself, whose belief systems could also stand a bit of shaking up. Surely, if there's more to heaven and earth than is dreamed of in our philosophies, it's far easier to change the latter than the former.

And then it happened: Mere days later, I was offered the chance to write about a powerful solid-state amplifier, the likes of which I hadn't experienced in ages. How could I say no?

Electrocompaniet
Among the historically well-regarded makers of solid-state amplifiers—Mark Levinson, Krell, and Threshold come to mind—one of the most notable of all is from a nation with fewer inhabitants than the city of Baghdad: the Norwegian firm Electrocompaniet, whose 1973 premiere gained it recognition in virtually every hi-fi market around the globe.

That debut product, snappily named The 2-Channel Audio Power Amplifier (footnote 1) also heralded the arrival of Matti Otala, a Finnish college professor and electronics engineer whose work is also associated with Philips, Harman/Kardon, Nokia, and Robert Bosch GmbH. In 1973, Dr. Otala presented to the Audio Engineering Society a paper in which he described a distortion mechanism called transient intermodulation, or TIM, and which had otherwise gone undetected, apparently because the standard measurements of the day relied overmuch on steady-state test tones (footnote 2). Dr. Otala proved that the nonlinearities he described were audibly present in solid-state amplifiers that used global feedback to reduce other, more commonly known distortions.

For the technically minded, Otala's work influenced the way we look at feedback loops and amplifier slew rate; for those more interested in audio philosophies—there's that word again—Otala and, by extension, Electrocompaniet underscored the danger in suggesting that any existing suite of measurements can say all that needs to be said about an amplifier's musical performance, and reminded us that measuring without listening is of limited value. (So, too, is the opposite—for the designer, at least.)

Matti Otala never actually worked for Electrocompaniet; today he's a professor of Technology Management at the University of Technology in Tampere, Finland. But the Norwegian engineer Terje Sandstrom, who was instrumental in turning Otala's theories into a practical commercial amplifier, continues as mentor to Electrocompaniet's design team—whose recent fruits include the AW400 monophonic amplifiers ($12,500/pair). The AW in the model designation is a subtle reference to Electrocompaniet's Ampliwire models of bygone years, while the 400 signifies that this solid-state amp is capable of passing 400W, without clipping, across an 8-ohm load (not to mention 765W across 4 ohms and 1010W across 2 ohms).

The Electrocompaniet AW400 has the added distinction of being fully balanced: From its tidy input boards through the appropriately rugged banks of heatsunk output devices, each AW400 is as symmetrical an amp as I've seen—although I could see less of their innards than I'm used to, given the manner in which the circuit boards and RF shields are arranged. (A telltale bolt betrayed a toroidal mains transformer, but other parts of the puzzle remained unseen.) I was very impressed with the AW400's mechanical construction: The sheet-metal chassis, in tandem with a pair of metal straps between the two banks of heatsinks—not unlike the crossbars one sees in the engine compartments of certain high-performance cars—provide the requisite rigidity, without the kind of crazy-high mass that adds far more to the cost than to the performance (in my opinion). And the front panels are nicely finished sheets of clear acrylic, backlit in blue—beautiful, but not, in the manner of other high-end amps, pointlessly so.

I discussed that with Peder Beckman, CEO of Electrocompaniet North America, who offered the additional loan of an Electrocompaniet EC 4.8 preamplifier. Thus I allowed myself an extra couple of weeks to absorb the sound of only the fully balanced EC 4.8 in my system, accomplished with the help of some Shindo XLR-to-RCA interconnects borrowed from Tone Imports. After that, I moved the Electrocompaniet EC 4.8 to my (Quad ESL–based) living-room system; the AW400 amplifiers spent several weeks being driven in single-ended mode, by my Shindo preamp in my main system, before resuming balanced operation for a final week with the EC 4.8 and the Quads.
The reason for all that: An amplifier such as the Electrocompaniet AW400 can't perform its best in single-ended mode. For one thing, to use it with a nonbalanced preamp required that I plug an XLR-to-RCA adapter (supplied by Electrocompaniet) into each amp's input jack—itself a performance limiter. More significant, apart from the obvious mechanical chores, those adapters work by connecting the negative contact to ground, thus asking the output section to swing the whole of the audio signal in one direction, and leaving a goodly portion of the amp's capabilities untapped.

Apart from all that, the Electrocompaniet amps posed no extraordinary requirements. In both my systems, they operated while standing on hardwood floors—their size precluded the use of any of the accessory stands or bases I had on hand—and I used them with their stock AC cords rather than any aftermarket types. The AW400s never became more than moderately warm during use, even while driving the notoriously cranky Quads, nor did they behave badly in any other way, apart from a faintly audible trace of hum in single-ended mode.

One small caution: The Electrocompaniet AW400 is, in fact, a DC-coupled amp. And as I discovered when I first experimented with the OMA slate plinth for my Thorens turntable (see "Listening" elsewhere in this issue), the AW400 is capable of passing very-low-frequency signals through the speaker to which it's connected. In particular, if your turntable setup requires work, and/or your floor is unusually sensitive to footsteps, you will hear those problems through the AW400s.

Listening
The first really great solid-state amp I heard in a perfectionist system was an Electrocompaniet Ampliwire. I've carried around the memory of that remarkably sweet-sounding amp for 25 years or so. That may constitute a bias.

But let me back up just a little: In my experience, early hi-fi sound, especially mono, was noted—with pleasure—for reproducing the sounds of instruments and voices with presence and solidity. Its greatest failing, to some, was that early hi-fi made everything sound solid and present, such that there was no sense of the space that exists between notes, and sometimes seems to surround each performer. At its best, early hi-fi could sound convincingly tactile, but it was always more opaque than the real thing.

By the late 1970s and early '80s, the sound by which some hobbyists came to identify high-end audio took shape in the salon showrooms of New York City (and elsewhere, I guess): an airier, "puffier" sound than the old gear made, wherein the soundfield as a whole, and everything within it, became much more open, even "pellucid." But that sound, too, came to disappoint, for its fussiness and lack of substance. (I know: Some people are never satisfied!)

What I enjoy hearing is reproductions of music wherein instruments and voices are solid and colorful and real, and yet the space between those things isn't filled up with a lot of shit. Some tube gear nails that—low-power stuff, mostly, in my experience—but not all. I remember thinking some relatively inexpensive and similarly low-power transistor amps could do that, too. Maybe it's an overly rosied-up memory, but I think the Naim Nait 2—the early version, when it still had a phono preamp—could do it, as well as that fondly remembered Ampliwire.

Maybe it's a house sound: The AW400s played my favorite stereo recordings with that same solid yet open presentation. Solo voices were believably substantial, especially from the better-sounding opera recordings in my collection, such as Cavalli's L'Ormindo with the London Philharmonic under Raymond Leppard (LP, Argo ZNF 8-10), and Puccini's La Bohème with von Karajan and the Berlin Philharmonic (LP, Decca/Speakers Corner 565/6). Yet the presence of the performers—and their movements, when called for—was enhanced during playback by an equally real and engaging sense of the space around them. At no time was that more true than with Luciano Pavarotti's soaring "Che gelida manina," in La Bohème.

And that was just the sound. The Electrocompaniet amps were musically accomplished as well, with especially good momentum with all upbeat music, including classic rock: My favorite Blue Öyster Cult collection, Secret Treaties (LP, Columbia KC 32858), was especially fun through the combination of Electrocompaniet AW400s and Wilson Audio Sophia 2 speakers. With well-recorded bluegrass, Dawg music, and other acoustic fare, the musical flow was satisfying but not as good as it gets: Through the big AW400s, lines of notes didn't unravel with quite the crazy, organic, psychedelic ease as with the very best low-power tube amps.

But I'm getting ahead of myself: The first song I actually listened to through the AW400s was Procol Harum's "Strangers in Space," from the newly reissued (and exceptionally well done) Something Magic (CD, Salvo SALVOCD029). Unrepentant tube snob and digiphobe that I am, I listened through the opening bars of Pete Solley's analog synth sounds, bracing myself for steely highs that didn't come. But I was still unprepared when Gary Brooker's voice entered, dead-center and sounding more whole than I'd ever heard it in my room. I listened on: His breathing was apparent, but neither that nor the sense of air around his mike was audio-nerdily exaggerated. (In my listening notes I scribbled the admittedly unoriginal observation, "It's like he was there," and emphasized it with a juvenile profanity.) No, Something Magic wasn't Procol at their best, but to hear it played back that well was to fervently wish that that particular lineup had made more than one album.
After several weeks with the AW400s—and, again, with the Electrocompaniet-Wilson combination in particular—I'm here to tell you: There is, quite simply, no earthly substitute for listening to the last 90 seconds of Mahler's Symphony 3 with a very powerful amplifier and a full-range loudspeaker. The version recorded in 2002 by Michael Tilson Thomas and the San Francisco Symphony Orchestra (AIFF/CD, San Francisco Symphony 821936-0003-2) is the one that actually precipitated that observation, but you might also try the very good Bernstein/New York Philharmonic (LP, Columbia M2S 675) and, for my money, the best of all, by Jascha Horenstein and the London Symphony (LP, Nonesuch HB-73023). As Hud says near the end of Cloverfield: "Yeah, that's the shit!"

So, too, might fans of classic rock believe that few combinations are more capable of putting across the force in their favorite music. Never mind that most of the genre's classic recordings are wildly overcompressed and exhibit a dynamic range that never strays far from 85–100mph—there are some wildly fine exceptions, and that's where the Electrocompaniet shone. Among them is a wonderful gem by the Who, Live at the Isle of Wight Festival 1970, containing a complete performance of Tommy (AIFF/CD, Columbia/Legacy C2K 65084). My usual combination of low-power Shindo tube amps and high-efficiency Audio Note loudspeakers is dramatic and fun on that and similar recordings, but there's a quality to the attack of each of those power chords and electric-bass notes—some facet of their overall sense of impact—that my reference combination misses. The Electrocompaniet amps driving the Wilson Sophia 2s nailed that impact, that punch, and the music was more enjoyable for it. But the AW400s did more well than just that: Their openness and clarity were a joy throughout that recording, from the subtlest stage banter through the downright sweet, singing tone of some of John Entwistle's bass lines—what a flexible, inventive performer he was!—to the wonderfully uncompressed sound (at least on this recording) of Keith Moon's drumming. Absolutely riveting stuff.

That brings to mind a final performance note: I spent a fair amount of time listening to the Electrocompaniets through my old Quad ESLs, and, as so often happens when the subject turns to Quads, the results were often surprising. To revisit a description I offered a moment ago, the combination didn't have the same easy, organic sense of note-flow as with a good tube amp, especially the 20Wpc Shindo Haut-Brion. Nor did the AW400s reproduce all of the deep textures of various reed and string instruments, such as Julie Price's beautifully played bassoon in Elgar's Romance for Bassoon and Orchestra, Op.62, with Paul Goodwin and the English Chamber Orchestra (CD, Harmonia Mundi HMU 907258). That said—and you can accept this or not, as you wish—the combination of high-power solid-state amp and Quad ESL sounded tighter and punchier than I imagined would be possible. Perhaps obviously, the sound wasn't nearly as forceful as with the Wilsons—but it was fun nonetheless! (NB: I wouldn't dream of trying the combination without a voltage-limiting protection circuit on my Quads;

Conclusions
In a perfect world there would be enough room, enough time, and enough money that we could sample everything under the sun, anytime we liked. To an audio enthusiast, that's no small matter: There are thousands of different products available to us—special emphasis on different—and yet we're allowed to change our philosophies only once or twice in a lifetime, lest we run afoul of The Rules.

What the hell: Do it anyway.

I know a good place to start: The Electrocompaniet AW400 is a sweet, fun, and unabashedly powerful-sounding amp. It's an easy recommendation for listeners who need this combination of force and musicality, and a potential ear-opener for those who haven't tried such a thing in a while. Surprised though I was in a philosophical way, the AW400 is an expectedly great amp from a company with a remarkable history.