Solid State Power Amp Reviews

Then, to reacquaint myself with the sound of my reference system in my room, I spent some time listening to my B&W 800 Diamond speakers and my other amps. Only after that did I put the M1s back to work. As when test driving a powerful sports car, my first impulse was to see what the M1s' power could do. I wasn't disappointed—as much as I tried , within and sometimes beyond the limits of propriety, the M1s drove the 800 Diamonds to clean and undistorted output. Whether it was the conclusion of Mahler's Symphony 2, with orchestra, chorus, and organ all at full tilt, or the conclusion of Pink Floyd's Dark Side of the Moon with the gain up to 13, the short stack of M1s spewed out power without complaining, or even getting noticeably warm, instead seeming to say, "This all you got?"

I responded with: "The Gates of D&3228;fos," from Mickey Hart's Däfos (CD, Rykodisc RCD 10108); Blue Man Group's "Piano Smasher" and their outrageous rendition of "I Feel Love," from The Complex (CD, DTS Entertainment WAX53138); and Jean Guillou performing his overwhelming transcription for pipe organ of Mussorgsky's Pictures at an Exhibition (CD, Dorian DOR-90117). Then I gave up. Even with two—or three—M1s plugged into the same dedicated 15A/120V line, the Anthem amplifiers seemed to be sources of infinite power as they drove the (essentially) 4 ohm B&Ws. I needed no more.

After a good night's sleep to refresh mind and ears, I began listening to music at more sensible levels. The sound was smooth and warm but lacked bite, and wasn't particularly engaging. Most notable was a lack of high-frequency energy, though what was there was quite elegant and detailed. In isolation, the treble was just fine, but it sounded rolled off. Bass was, as you might expect, powerful from the very bottom to the midbass, but seemed dominated by the range just around 100Hz. This tended to mask true low bass on normal recordings, although genuine low end could be impressively revealed by such percussion-heavy fare as "Yulunga (Spirit Dancer)," from Dead Can Dance's Into the Labyrinth (CD, 4AD 45384-2), or "Jazz Variants," from the O-Zone Percussion Group's La Bamba (CD, Klavier KD 77017).

With these spectral issues, it should be no surprise that I found the soundstage contained and congested. I suffered much consternation over this—the M1 is clearly the result of impressive engineering, and Anthem has such a great track record as a producer of good-sounding electronics. Experimenting with the A/V power arrangements made no improvement, nor did fiddling with the M1s' trigger and gain switches. Switching from balanced to single-ended operation was equally ineffective.

I asked Anthem whether the review samples might be early-production units. The response was "yes," and that minor changes had since been made and incorporated into current production. A new pair of M1s was dispatched to me and, after a few days of burn-in (footnote 1), I resumed my listening. I was assured that the changes would not affect the M1's specifications, which was confirmed by JA on the test bench (see his "Measurements" sidebar).

A Second Helping
Many years ago, I fell into a record store (remember those?) in Manhattan very late one evening and asked the young man behind the counter if he had anything by Jennifer Warnes—I'd just heard about her Famous Blue Raincoat. The clerk paused, then said, "That's regular music, isn't it?" He couldn't find that CD, nor, to this day, do I know what he thought was regular—but for most of us, it's what we regularly listen to. Now was the time for the M1s to play some regular music.

It was immediately apparent that the new amps provided the detail and treble extension the originals lacked. Brass instruments regained their squillante bite, and brushed cymbals sounded more like the real thing. High voices, too, took on a more natural ring, and the soundstage was wider and significantly deeper.

With orchestral recordings, the balance of the sound via the M1s and the 800 Diamonds was now full and rich—much what I've come to expect from my system. The new amps' improved treble was better balanced with the mid- to upper frequencies, one of the results of which was that the upper harmonics of instruments were in natural relation to their fundamentals. I particularly enjoyed Iván Fischer and the Budapest Festival Orchestra's recording of Stravinsky's Rite of Spring (SACD/CD, Channel Classics CCS SA 32112), with its detailed instrumental array and the woodwind voicing across a believable soundstage. The bass was very powerful-sounding, though this recording and performance is, unlike many, less a sonic blockbuster and more an exciting ballet score. Similarly, a new recording of Shostakovich's Symphony 11, with Peter Oundjian leading the Toronto Symphony (TSO Live, www.tso.ca), was thrilling. This little-known Shostakovich cycle goes from success to success; the brooding opening of 11 is a model of artful suggestion, and the M1s provided ample weight for the lower strings, even at low volume levels, while opening up to the startling climaxes hurled at us by Oundjian, the TSO, and the excellent recording team.

Smaller ensembles, as on the two-channel tracks of the Blu-ray remastering of Patricia Barber's Modern Cool (Premonition 90761-4, October's "Recording of the Month"), also benefited from the new samples of the M1. There were the punch and momentum that distinguish this version from its CD predecessors, as well as the striking presences of Barber's voice and piano. Solo violin, too, was all sleek delight, as exemplified by Julia Fischer's performance of Tchaikovsky's Souvenir d'un lieu cher (SACD/CD, Pentatone PTC 5186 095). In contrast to Fischer's silvery string tones, the piano accompaniment by the late conductor Yakov Kreizberg seemed of somewhat baser metal. This seemed not due to Kreizberg's playing or his piano or the recording, but to confirm that something was amiss in the way the M1 delivered bass.

We know that the ear/brain adapts well to sounds, coming to accept as normal what it's been exposed to for an extended period. This has survival value in permitting us to recognize behaviorally significant sounds—of those we love as well as of those we should fear—across a wide variety of acoustical environments, and it underlies our inability to make valid judgments of subtly different sounds unless they are presented in rapid succession. It also endows us with a bias, as to what is "natural," against new stimuli in favor of those that are or are becoming familiar (footnote 2).

Thus, I was able to enjoy the Anthem M1s while listening to them full-time over a period of weeks, until the accumulation of anomalies noticed in familiar recordings made it necessary for me to focus on what was going on in the bass. Patently, power and extension were not problems for these amps; but bass balance and clarity were. Piano, as noted above, was a problem because notes from the left side of the keyboard took on a somewhat leaden tone. Moreover, the overbalance and loss of focus in the upper bass at around 100Hz deprived the lowest bass of its incisiveness, and the soundstage of its open, airy dimensions.

A good example was Hans Theessink's classic recording of "Late Last Night," from Call Me (CD, Blue Groove BG-4020). What I and others find so attractive about this cut is the gritty texture of Theessink's deep voice. Through the M1s, the grit was swallowed by the fundamental tones and the singer's unique character was muffled. Leonard Cohen's voice suffered equally. Tenors sounded more baritonal. Other examples: electric bass guitar, acoustic double bass, and timpani had huge power and presence via the Anthems, but at the cost of much of their distinctive tonal qualities.

Since JA's measurements (which I didn't see until after this review had been written) show that the M1s have a flat frequency response, as well as low distortion and noise, how can I have confidence in my observations? First, I'm very familiar with my reference recordings, having heard them with varying review equipment as well as with my reference setup. However, I claim no superhuman capabilities, and acknowledge that I'm as susceptible as anyone to adaptation and expectation bias. But there's another reason I'm confident in my reporting: I have on hand three other more-than-decent power amps, and with some effort have learned to swap pairs of XLR and speaker cables between any two in less than 15 seconds. It's not quite A/B, but the M1's bass excess and poor bass definition were apparent in dozens of such comparisons using several different recordings. It also became apparent that this flaw, once my ears had become attuned to it, colored the overall tonal balance of almost every recording I played. In these comparisons the M1s always seemed warmer and less spacious than my other amps. I'm certain that the other amps can't all be wrong.

Finally, I tossed the M1s into a taxi and persuaded a friend to insert them in his system, which, though excellent in every way, has no components in common with my own. The verdict was the same.

Check, please
I have great respect for the team at Anthem Statement, and despite everything, I think the M1 has great potential. I spent many weeks enjoying "regular" music with it, and it impressed with its reliability, its power, its general clarity, and, with the high-frequency improvement in the current-production samples, its warm tonal balance. I have no doubt that there are those who will find the M1's balance to their taste, or useful as a complement to an otherwise bright-sounding system and/or room.

But in its present state I cannot recommend the M1. It imposed a tonal signature on the sound that was simply not neutral. Many successful audio products fail to meet this criterion, and some are perhaps designed to do so, but I don't believe that this was Anthem's goal. Perhaps, as they've done with the upper treble, Anthem will be able to further voice the M1 and let it sing at lower frequencies. I sure hope so.

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Footnote 1: I don't believe that burn-in plays a significant role in the sound of modern electronics. Nonetheless, to preclude the objections of those who believe it does, I subject all review samples to burn-in.

Footnote 2: Burn-in, Part 2: A significant part of the phenomenon of burn-in, especially in noncontrolled, observations, is that we adapt to stimuli as they become familiar and accept them as a reference. Ever notice how the effect of burn-in is always positive?