Lamm ML2.2 monoblock power amplifier
In truth, it wasn't the fault of fate or even God, but of my own doing: Having reviewed the Lamm ML2.1 monophonic amplifier ($29,290/pair) in Stereophile's October 2004 issue, and having been so impressed that I bought the review pair and kept them as my reference for a couple of years, I felt compelled to hear that amplifier's successor. My opportunity came with the announcement, last summer, of Lamm's ML2.2 monoblock ($37,290/pair); soon thereafter, a review pair was dispatched to my home via air freight. (It may seem extravagant to spend hundreds of dollars to get a pair of amps from Brooklyn to upstate New York, but designer Vladimir Lamm decries all but air when it comes to transporting his products, notwithstanding their robust crates; my Volkswagen and I made a tentative effort to collect them during a trip to the Borough at the Center of the Audio Universe, but fate and God intervened.)
Like its forebears, the 18W Lamm ML2.2 is a single-ended-triode amplifier built around a somewhat unusual choice of power tube: the Russian 6C33C indirectly heated triode. You've probably heard the suggestion that Russian fighter jets can remain airborne in the wake of the electromagnetic pulse from a nuclear explosion, owing to their tubed control electronics; this is the tube in question. The 6C33C, originally developed as a voltage regulator, has a number of appealing qualities, including very low impedance, concomitantly low plate voltage, excellent durability during war and peace alike, and abundance. I think they also look nice.
Also like its forebears, each ML2.2 has two 6C33Cs: One is the output tube, operated with a B+ rail of just 175V, while the other reverts to type and assumes the role of output-section voltage regulator. That's rather noble, when you think about it.
The five remaining tubes in each ML2.2 are all small-signal devices, two of whicha 6AK5 sharp-cutoff pentode and a 5651 cold-cathode diodework with the output-section regulator described above, and do not amplify the signal. The other three tubesone 12AX7 and two 6N6P (also Russian, also plentiful)are dual-triodes, used for voltage gain in a circuit derived from that of the Lamm ML3 ($139,490/pair), which endures as the company's flagship. The new input circuit is said to be one of the main differences between the ML2.1 and the ML2.2.
Another difference: As I described in a Follow-Up on the Lamm ML2.1 in the September 2005 issue, output-tube failures in that amplifier, though rare, were occasioned by the blowing of a 1.25 amp plate-current fuse. That doesn't sound like the worst thing in the world, except that the fuse was mounted internally, on a circuit board decorated with lightning bolts, exclamation points, and other outward signs of warning; to get at it, one had to unplug the amp, remove its tubes, turn the 81-lb chassis upside down, and remove a panel that's held in place with 18 machine bolts. For the ML2.2, that fuse and its holder have been relocated to the top panel, within easy reach. Nice.
The remaining refinements in the ML2.2, according to Vladimir Lamm: a new and reportedly better power transformer (the output transformer, custom-made to Vladimir Lamm's design, remains the same); five power-supply filter chokes instead of two; new circuitry that allows owners of Lamm preamplifiers to operate the ML2.2's power switch remotely; printed-circuit boards made of a higher-quality material; and upgrades of various parts.
Like its predecessor's, the ML2.2's chassis is cleanly designed and neatly and solidly built, giving an appearance that's serene, purposeful, and foursquarebut not at all exotic. The brushed-aluminum faceplate, which is anodized black, is appropriately thick but not excessively so, and the metalwork is clean, well finished, and very robust. Mounting bolts for various fasteners are integral to the inner surface of the chassisthere are no sad-looking globs of adhesive or silicone sealant inside this ampand the wiring and soldering are as neat and precise as I've ever seen. This is a staggeringly well-built amplifier, but also one without the slightest concession to luxury.
Installation and setup
Buying a pair of Lamm ML2.2 amplifiers is not like bringing home a toaster oven, discarding the carton and instructions, and settling in for a long, easy life of open-face sandwiches: Enthusiast products just don't work that way. And as bullish as I am on high value and common sense, it's also the duty of the enthusiast press to say that, if you believe ever-more-expensive products should naturally be ever more easy to use, then neither the ML2.2 nor this review is for you.
First of all, the Lamm ML2.2 is extraordinarily heavy: 107 lbs in its reliably sturdy and generously padded wooden crateand that's just one channel. If you don't have a good dealer (or male children, or servants), you're faced with a considerable challenge just to get the amps into your house or apartment, out of their packaging, and onto whatever surface will support them.