Lamm M1.2 Reference monoblock power amplifier Page 2
The speaker output is taken from a pair of brass binding posts; a third binding post allows for independent grounding of the chassis, if necessary. Very usefully, in light of the M1.2's weight of 68.5 lbs, there is a pair of handles on the rear panel as well as on the front. When the amplifier is turned on, the output is muted and the red front-panel LED flashes while the tube warms up and the circuitry stabilizes. When the M1.2 Reference is ready to handle some music, a relay clicks and this LED glows steadily.
I began my auditioning with the BBC LS3/5a's, which are definitely high-impedance loudspeakers. I therefore used the "816 ohms" bias setting. When I changed to the Quad ESL-2805 electrostatics (review to appear shortly), because these drop below 8 ohms in the upper midrange and treble I switched to the "16 ohms" setting. I also tried both bias settings with the Sonus Faber Amati Futuras and TAD Compact Reference CR1s. With all four speakers a consistent difference emerged: the low frequencies were too warm at the high-impedance bias setting. Even with the LS3/5a's, the low frequenciesor what there were of the low frequencieswere a bit better defined with the low-impedance setting.
For example, last May I celebrated my 25th anniversary at the helm of Stereophile by guesting, along with trumpet player Liam Sillery, with the core of Bob Reina's free-jazz band, Attention Screen, at Otto's Shrunken Head, in the East Village. I played my usual fretless bass guitar while the band's regular bassist, Chris Jones, played acoustic bass. (Having two bassists led to some interesting textures, as each of us tried to stay out of the other's way.) I captured the gig at 24-bit/96kHz with a Zoom H4n, which records audio to an SD memory card. Though it has inputs for two external microphones, the inexpensive Zoom recorder includes two reasonably neutral cardioid mikes; to save time in setup, I used those for the Otto's gig.
Back home, it was apparent that I needed to apply a small amount of midbass boost to the WAV files to compensate for these mikes' farfield rolloff below 150Hz or so. When I used the Lamms set to "816" and judged by ear the amount of EQ needed, using Pure Music's Audio Plug-Ins function and the Bias SuperFreq-4 VST equalizer, there wasn't quite enough boost when I reset the Lamms' bias to "16." I'm not talking about much boosta shelf of a few dB below 125Hzbut the point is that my judgment of how much boost was just enough depended on the M1.2's bias setting.
Bill Frisell's tribute to John Lennon, All We Are Saying . . . (CD, Savoy Jazz SVY17836), our December 2011 "Recording of the Month," was in heavy rotation while I prepared this review. Ultimately, the "816" bias setting made the double bass in Frisell's version of "Nowhere Man" sound too thick, so I ended up using the "16" setting for all the speakers I drove with the M1.2 References. I never felt I was running out of power with this setting, and it still gave a rich sound that benefited Kurt Sanderling's early-1970s performance of the Brahms Symphony 3 with the Dresden Staatskapelle (RCA CD, long out of print)I love that third movement, with its simple triple-time melody woven by the composer into a rich tapestry of lyrical longing.
Although I preferred the "16" bias setting overall, the Lamm M1.2 didn't quite have the low-frequency acuity of the Classé CT-M600. But neither did it sound as cool as the MBL 9007. The M1.2 Reference had a somewhat more robust, less delicate balance than either of the other amplifiers; in that respect it was similar to the Musical Fidelity AMS-100, which I reviewed last September, and which also has an output stage biased into class-A.
But what the Lamm did have was almost a glow to its presentation, which worked magic with mono recordings. As I write these words, Pure Music with iTunes set to Shuffle has found Ketty Lester's hit from 1962, "Love Letters"who knew that that sparse ostinato piano figure, so reminiscent of Floyd Cramer, was played by Sheffield Lab pianist Lincoln Mayorgaand the sound has a richness, a fullness, that belies both its vintage and the fact that it's a 320kbps AAC file.
And if the Lamm amplifiers gave a glow to a vintage mono recording, when fed true audiophile fare they created a solid, stable, and vast three-dimensional space. I recently purchased, from HDtracks, 24/88.2 files of trumpet player Jon Hassell's Fascinoma (FLAC files; CD, Water Lily Acoustics WLA-CS-70-CD). The spaciousness of the arrangements is matched by how producer Ry Cooder and engineer Kavi Alexander have placed the instruments within the apparently vast space of a Santa Barbara church. With the Lamm amps driving LS3/5a's, Hassell's treatment of that old big-band favorite "Caravan" lit up a huge space between and behind the speakers, with Jacky Terrasson's piano placed way behind the wall of my room.
Even when less space had been captured on a recording, the Lamms worked their spatial magic. Some years ago, Stereophile's webmaster, Jon Iverson, released a self-recorded CD, Alternesia (MA), in which he explored the cross-fertilization of traditional Balinese gamelan forms and Western grooves. Because the CD is out of print, Jon has made the album available as a free download from www.alternesia.com as high-quality FLAC, WAV, and AIFF files, covered by a Creative Commons license. With the exception of some bass samples, everything you hear banged or blown on Alternesia was recorded, one instrument at a time, to an MCI analog tape recorder using AKG C414 mikes, the mike preamps feeding the recorder with no intervening mixing desk.
There is thus a purity to the individual sounds on this album that the Lamm amplifiers reproduced in full measureand particularly when driving the Quad electrostatics, with which they formed a synergistic coupling. The contrast between the harmonically related fundamental tones that followed each metallophone's transient with the sometimes enharmonic overtones was almost fetishistic. But the Lamms' attention to detail and soundstaging was not achieved at the expense of the rhythmic flow that Jon achieves with the drums on each of Alternesia's eight tracks.
I deliberately didn't reread Paul Bolin's 2005 review of the M1.2 Reference until after I'd finished my listening and written the words above. Now that I have, I find it uncanny that he used the same word, glow, to describe its characterthe M1.2 "was bogglingly transparent and had state-of-the-art resolving capabilities," he wrote. "That resolution and transparency were combined with a harmonic completeness, timbral richness, and glow reminiscent of Conrad-Johnson electronics from the mid- to late 1980s, only without the slowness and caramel coloration." I don't think I can say it, and I haven't said it, better.
Even at a time when amplifiers costing upward of $50,000 are becoming, if not common, then at least not as rare as they used to be, $23,890/pair is still a substantial amount of money to lay out on a pair of hot-running monoblocks with a nominal 110W rating. But given that it has been in production unchanged for more than eight years and continues to offer the same superlative sound quality and measured performance, the Lamm M1.2 Reference would seem to be a wise investment. As Paul Bolin wrote, this is a great amplifier. Highly recommended.