Solid State Power Amp Reviews

The Logic MC20 arrived on a disagreeable day, so I was glad to see that Halcro double-boxes their amps, and that their packing materials and other ancillaries are of apparently high quality. One curious thing I did notice during setup was that the MC20 has the most resonant enclosure of any contemporary amp I've tried. If you run your finger along the cooling vents on its top surface, the way a child might pass a stick over the tines of a wrought-iron fence, you'll hear quite a loud sound. The first time I produced the noise by accident, I thought the phone was ringing elsewhere in the house.

The chassis is a mix of castings, stampings, and machine work, most portions of which are reasonably light. (The prospective owner is not, in other words, being forced to pay for a foolishly massive, sculpted faceplate.) It's worth noting that the Halcro Logic MC20 was more difficult to take apart than most amps that come my way—you'd almost think they don't want me to electrocute myself. I persevered nonetheless, and my stubbornness was rewarded with a glimpse of several components whose function I couldn't even begin to identify, save for a large, mostly sealed-off power-supply module.

Even though the manual says that the MC20's break-in period is completed at the factory, I let it run in for about a week before taking any serious listening notes. For the most part, I used the MC20 with my Quad ESL-989 loudspeakers—the idea of a 400Wpc amplifier driving my Lowther horns was just too nutty to try—playing a variety of LPs and CDs at the generally sane listening levels I prefer.

And I must say
The Halcro Logic MC20 really did sound immediately, and significantly, different from most other amplifiers that I've experienced. I didn't have to strain at all to tell the MC20 apart from anything else in the house.

Its most obvious performance characteristic was something that I can describe only as an enormous sense of clarity. The sound of the MC20 was exceptionally, conspicuously uncolored and unsoiled by noise or textures that didn't belong there. On record after record, it placed musical sounds in front of me with a physically big but, at the same time, simple and unspectacular hear-through quality—transparency, if you prefer. It made a big, agreeable, convincingly whole mass of sound between the speakers, every time out.

Those qualities were all in good supply when I tried out André Previn and the London Symphony Orchestra's recording of Rachmaninoff's Symphony 1 (LP, EMI ASD3137), which is itself one of the very best, most transparent-sounding orchestral recordings to be made in the 1970s. The Halcro, while remaining tuneful throughout, with no detectable distortions of pitch relationships, made the timbral colors and spatial realism captured in that recording even more beautiful and impressive than I remembered. By comparison, my Lamm ML2.1 monoblocks provided more in the way of tactile qualities and overall presence and spatial depth, but exhibited less poise and calm in the loudest, most frenetic bits—as in the somewhat obvious (but nonetheless satisfying, and presciently cinematic) final movement.

Hearing the Rachmaninoff reminded me to pull out another of my favorite classical records, the Adrian Boult–New Philharmonia recording of Elgar's Dream of Gerontius (LP, EMI SLS 987), which was made not long thereafter by the same team of producer Christopher Bishop and engineer Christopher Parker (although the two recordings don't sound all that much like one another). The Halcro was poised and forceful—no signs of strain that I could hear—on the loudest passages, such as the insistent drumbeats in the demons' chorus and the tam-tam crash at the moment of judgment.

The Halcro was very good, too, at capturing sonic subtleties, such as the return of the clock motif in the harps late in the work—and musical subtleties as well, such as the (deliberately perverse, I think) bounciness of the fugue-like scoring for the choir that begins when the word dispossessed is passed around among different sections of the choir, and the return of the prayer motif halfway through tenor Nicolai Gedda's final, brilliant solo. There remained sonic differences between the Halcro and the Lamms, of the sort that will tip some listeners' preferences one way or the other—such as the Lamms' superior sense of spatial depth, especially inasmuch as the Lamms allow the choir to sound as if they're coming from an area several feet behind the soloists—but there was no mistaking the musical sense, and the consequent emotional satisfaction, that the Halcro delivered with that record.

After weeks of listening, while I found that the MC20 conveyed consistently less spatial depth than my reference amps, I became equally convinced that the Halcro nonetheless gave a very clear idea of spatial perspective between different sounds within the "stage." That became obvious during a furniture shuffle in my hi-fi room, when I found myself sitting closer to my Quads than usual. While listening to guitarist David Grier's brilliantly performed and equally well-recorded Panorama (CD, Rounder CD 0417), I was struck by how forthright, stable, and utterly believable the players' positions were on the stage relative to one another. Mike Compton's mandolin, in particular, was utterly there at stage right, and the quality of presence was so convincing that I could've sworn I sensed the interaction between Compton and Grier toward the end of the former's solo, when his single notes morph into syncopated chording and Grier's guitar echoes that from the background. Lovely.

Conclusions
The Halcro Logic MC20 impressed me in almost every way: It's a magnificent-sounding amp. It may indeed be more timbrally neutral than my Lamm tube amps, and it was equally good in the area of image stability and precision, as well as in its ability to put across very-low-level detail—to not only let me hear subtle things that were otherwise buried in a recording, but to present them in a way that made sense alongside everything else, and that, under the best conditions (good music, good mood, good health, etc.), could result in an emotional or even physical response. That's worth noting, given that those performance aspects are already among the Lamm's most notorious strengths. And when it came to poise and lack of strain at the loudest end of the scale, the Halcro's superiority was as obvious as it was welcome.

Where the MC20 fell short of my reference was where most other amps seem to, as well: While the Halcro didn't sound mechanical per se, the Lamms allowed music to sound that much more human and organic: Lines of notes had a more natural flow through the Lamms—which also retained their edge in preserving that last, eerily convincing sense of texture in the sounds of instruments and voices.

But for $25,000 less, and given that it plays music superbly well in its own right, you can be more than forgiven for keeping the Halcro nearer the top of your must-hear list for 2006: Consider yourself urged. And while I haven't the slightest idea how to appraise the worth of its parts, it seems that the sheer sophistication of the technology behind the Halcro Logic MC20, let alone its very good performance, qualifies it as a good value.

Beyond that, I suppose everything's relative. There's a sizable Amish population in this part of upstate New York, and passing their one-horse buggies in my car is more or less a weekly occurrence. To them, my vehicle would be almost unimaginably powerful; to a car enthusiast, my 120hp Subaru is the anemic bottom of that company's line. And so it goes.