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Equipment Review
September 2008

Lamm Industries ML3 Signature Mono Amplifiers

by Marc Mickelson

"More than a different breed -- a new species."

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Review Summary
Sound "Super-charged SET amplifiers" -- bass "depth and power for sure, but also an unerring transition to the midbass and above" along with a "wonderfully animated" midrange and "refinement to the extreme." "There is an intricate dance between resolution and naturalness, the sense that the amps are laying bare all musical detail in a very graceful way. This can make solid-state amps, even very good ones, sound crude and uninvolving by comparison, and it advances even further what SET amps traditionally do best."
Features "A two-chassis 'no-compromise' single-ended amplifier that uses an esoteric direct-heated triode output tube. The separate power supply has six 12AX3 tubes as rectifiers and a custom-designed and -built transformer…. The circuit outputs 32 watts -- a healthy amount of power for a SET amp…. Input is either single-ended RCA or pseudo-balanced XLR, and speaker connections are included for 4-, 8- and 16-ohm loads. The ML3 Signature is said to deliver its full rated power into any of these loads."
Use The ML3 Signature is proudly a no-feedback design, which makes the inclusion of the feedback switches curious…. While adding feedback will lower output impedance, seemingly making the amps suitable for use with tougher loads, Vladimir doesn't advocate this…. Indeed, either feedback level softened the sound of the amps and foreshortened the soundstage. Try it and then forget it's there is my advice.
Value "One person who visited and heard the ML3 Signatures in my system put it best: 'I want them. I can't afford them, but I want them.'"

Depending on how you look at it, the American economy is either in recession or heading toward it, but there's no question that the dollar has sunk to record lows against currencies all over the world. Why then am I reviewing an American-made amplifier that costs a shade under $140,000 per pair? Because it's there, and it's made by Vladimir Lamm, whose track record for making significant audio electronics is set in stone -- or at least in print and pixel. His hybrid and tube amplifiers have received universal critical acclaim, including a number of praise-filled reviews from me. I've put my money where my mouth is, using many Lamm products as references for over ten years.

But anyone who designs audio equipment has to prove himself every time out, and Vladimir Lamm has created some colossal expectations for his ML3 Signature, not only because of its high price but because of the story behind it. It was at the beginning of Y2k, in the cement corridors of the Alexis Park Hotel, erstwhile site of the CES's audio exhibits, that Vladimir first told me about his upcoming amplifier based on the Russian GM70 tube.

"Ah, Marc. This GM70 is a very serious tube," Vladimir told me in his characteristic way.

"Better than the 6C33C?" I asked. This was the tube Vladimir had been using in his ML1 and ML2 amplifiers, and it's also a Russian export.

"Oh, yes. It has huge plate dissipation, 125 watts, and it is perfect for audio."

The theoretical part of the design work for the ML3 Signature was completed in 1982, but Vladimir didn't have the capital to begin building the amps until 2006. The ML3 Signature debuted at CES 2007. Well, to be truthful, it didn't exactly "debut." While the amplifier was at CES that year -- one monoblock -- it was on static display until the final day, when Vladimir decided to play it through a single Wilson Audio WATT/Puppy 8 speaker.

Even in mono, it was obvious that Vladimir's words rang true. The GM70 was a very serious tube, and the ML3 Signature was a very serious implementation of it: a two-piece amplifier finished in basic black for an astounding $126,290 USD per pair. By the next year, when a pair of the amps was on active display, the price had risen to $139,290, which is what the amps cost right now.

What accounts for such an interstellar price? I suspect it's a combination of things. First, there is the thing itself -- a two-chassis "no-compromise" single-ended amplifier that uses an esoteric direct-heated triode output tube. The separate power supply has six 12AX3 tubes as rectifiers and a custom-designed and -built transformer. Other tubes include a single 12AX7 -- nothing out of the ordinary there -- four 6N30P-DRs for which no substitutes exist, and that GM70. The circuit outputs 32 watts -- a healthy amount of power for a SET amp. Both chassis measure 16"W x 8 1/4"H x 20 3/8"D and together they weigh 160 pounds. They connect with a six-pin umbilical. Input is either single-ended RCA or pseudo-balanced XLR, and speaker connections are included for 4-, 8- and 16-ohm loads. The ML3 Signature is said to deliver its full rated power into any of these loads.

Feature-wise, the ML3 Signature is Spartan -- as most amplifiers are. Out of the ordinary are special jacks for connecting to a Lamm preamp, which allows for remote turn on of the amps. Each monoblock requires a small amount of user-performed adjustment via contact points on top of the main chassis. Here you insert probes of a volt-ohm meter and turn small trim pots to adjust each amplifier's plate current. In my opinion, the meter should be included with the amplifiers, though I'm sure Lamm doesn't do this because they think most owners will already have one. If you are meter-less, pick a good one -- a Fluke or BK Tools, not some RadioShack cheapie.

Also on top is an interesting and somewhat controversial feature -- a pair of feedback switches. The ML3 Signature is proudly a no-feedback design, which makes the inclusion of the feedback switches curious. "They are there mostly for educational purposes," is Vladimir's reasoning, the switches allowing owners to add 1.2 or 2.4dB of local feedback, meaning in the output stage only. While adding feedback will lower output impedance, seemingly making the amps suitable for use with tougher loads, Vladimir doesn't advocate this. "I prefer to deal with a healthy child," was his aphoristic explanation. Translation: Pick speakers that will work with the amps; don't tailor the amps to the speakers, even if you are able to by adding feedback. Indeed, either feedback level softened the sound of the amps and foreshortened the soundstage. Try it and then forget it's there is my advice.

Another possible reason for the extreme cost of these amps is the amount of brainpower Vladimir Lamm expended designing them, his current pièce de résistance. As I found out more than a decade ago, Vladimir developed a mathematical model of human hearing that has correlations to the design of audio equipment. The most obvious of these is what he calls the "absolute linearity of a system" (ALS), which, he explained to me, is a byproduct of some measurable parameters. Ideal amplifiers, as Vladimir defines them, will exhibit uniformity in their measurements, displaying THD vs. frequency at various power levels, for instance, as a series of straight horizontal lines at each power level. THD vs. power will show a gradual but unvarying rise in THD as power increases, and harmonic residue will resemble a perfect sine wave, the peaks and valleys rising and falling in equal amounts.

Putting aside the technical discussion, the idea here is that one can design amplifiers strictly by measurements, something Vladimir Lamm has done with each of his amps, eschewing listening. Vladimir admitted to me that he didn't even hear the ML3 Signature until he played that single monoblock at CES. Each of the Lamm amplifiers we've measured has come through without issue, sometimes exceeding quoted specifications.

Attaining good measurements from finicky tube equipment is the domain of a talented engineer, and this is also something you pay for when you buy a pair of ML3 Signature amps: the expertise of Vladimir Lamm to design audio electronics. Few individuals in the audio industry have created products with as universal an appeal and great critical recognition as Lamm, who updates products infrequently, believing in the idea of doing it right from the beginning rather than changing on the fly as new ideas come to him. Ultimately with the ML3 Signature you're paying for the time it took to finish the design -- a 20-year piece of Vladimir Lamm's working life, a significant part of his existence on this planet. How much is that worth?

Besides, amps like the ML3 Signature are not meant to be mass-market products any more than a Ferrari or Learjet is. The ML3 Signatures are luxury items that are financially out of the reach of most people, and that's just the way it is. Cynics will see gouging in their six-figure price, while believers will hear something that enlivens the slice of their lives it occupies. My first house cost $96,500; obviously I'm not the target buyer for these Lamm amps, but there are other people who are. "Quantity," Vladimir admits, "would bring the price down, but I am unable to make them in quantity." Indeed, each ML3 is a bespoke item, not something Lamm stocks. You pay your money and then you wait while Lamm builds your amps.

Finally, there is the highly subjective matter of the value of a set of sonic characteristics -- the "worth of sound," as it's often referred to. While some will dismiss the notion that any amplifier could be worth almost $140,000, Vladimir Lamm would say that's what it costs to make a significant jump in sound quality over his ML2.1 monoblocks, which are a sawbuck under $30,000 per pair. Of course, this explanation doesn't reveal what nearly $140,000 sounds like, but that's just where I can weigh in.

Used with…

Shortly after the Lamm ML3s arrived -- in four wooden crates -- a pair of Wilson Audio X-2 Alexandria Series 2 speakers arrived -- in seven bigger wooden crates. All of this was followed by Silent Running Audio Virginia Class platforms for the ML3s -- and four more wooden crates. Where would you store 15 wooden crates? In my case, on our back deck, which is thankfully covered, keeping the monsoon rains off all that plywood. Altogether, the crates take up about as much room as a mid-sized Buick, and with their contents inside they weigh about as much too.

Preamps used with the amps included a Luxman C-1000f, an Audio Research Reference 3, and an Aurum Acoustics CDP, which has a top-flight CD player built in. Other digital sources were an Ayre C-5xe universal player and Zanden Audio's wonderful Model 2000P transport and Model 5000S DAC -- which come in more big boxes! The analog source was a TW-Acustic Raven AC turntable with two tonearms: a Graham Phantom B-44 and Tri-Planar Mk VII U2. Dynavector DRT XV-1S stereo and mono cartridges were mounted on both 'arms at some point. Phono stages were the Aurum CDP's internal unit along with Audio Research PH7 and Lamm LP2 Deluxe outboard models. I used an AudioQuest LeoPard cable with the Graham tonearm, while the Tri-Planar has its own integral cable. Preamps, phono stages, universal player and turntable rested on a Silent Running Audio Craz Reference equipment rack, while the Lamm amps were used first on pieces of Corian and then on the Silent Running Virginia Class platforms, which were very worthwhile additions in sonic terms.

Interconnects and speaker cables were AudioQuest William E. Low Signature with a couple of pairs of Sky mixed in, or Shunyata Research's new Aeros-series Aurora-IC and Aurora-SP. Power cords were Essential Sound Products the Essence Reference or Shunyata Research Anaconda Helix and Python Helix in both Alpha and Vx variations. An ESP Essence Reference power distributor or Shunyata Hydra V-Ray cleansed power.

The Lamm amps that showed up here were a well-used demo pair that immediately displayed an unusual lateral shift of the soundstage. I flip-flopped the amps to make sure they were the cause, and the center image shifted in the other direction. Luckily it's easy to check the ML3 Signature's operating status (as long as you have a volt-ohm meter), and this revealed the problem: One of the GM70 tubes couldn't be adjusted to its normal plate current, so the amplifier in which that tube was used was noticeably lower in output. Lamm sent a replacement pair of tubes, and this solved the problem, reinvigorating the sound in the process. While the maintenance involved in owning tube amps gives some audiophiles cold sweats, the ML3 Signature and, indeed, all Lamm amps are about as easy to own as a tube amp can be.

You may be wondering why there are no measurements accompanying this review. It's not because Vladimir Lamm didn't want them -- quite the contrary, as we've measured many of his products in the past. No, the amps I received for review are serial numbers 1 and 2, and, due to a supplier issue, they have different output transformers than production units that followed. "The amps are sonically identical," Vladimir explained, "but their measurements will be slightly different from those of a production amplifier." Given this, we had a choice to make: publish the very first review of the amps or wait until Vladimir could send production models for review and measurements, which may never happen, given that Lamm doesn't have a stock of the amps. We went with the former -- and decided to divulge all of this for the sake of completeness. We hope to publish measurements of the ML3 Signature in the future (and I just might have to do some follow-up listening).

A very serious amplifier

One of the things that made the Lamm ML2 and ML2.1 such intriguing and unusual amplifiers was their ability to drive dynamic speakers that weren't particularly sensitive with just 18 watts. I still vividly remember connecting the ML2.1s to a pair of Wilson Audio Sophias, which we confirmed with our NRC measurements as a mere 86dB sensitive. Not expecting much, I was truly amazed at how easily the amps drove the speakers to loud levels -- louder than I would listen for more than a few minutes -- without clipping. SET amps are known for their low power and high output impedance, which makes them persnickety with speaker loads, but Vladimir Lamm had gone a long way toward overcoming this limitation, first with the ML2 and then with the ML2.1. Oh, and the amps sounded wonderful too.

The ML3 Signature pushes this inherent stability even further, nearly doubling the ML2.1's power output and making for a SET amp that can be used with an even wider variety of speakers. Ironically, however, the cost of amps will limit the pool in practical terms; you won't see owners pairing the ML3 Signatures with a pair of mid-line speakers, only the best of the best. And the sound will speak for itself, the Lamm amps showing no deficiencies in power or bandwidth and displaying midrange sophistication that pushes the music to graceful new heights. These are super-charged SET amplifiers.

A friend of mine who owns some very good hybrid and solid-state amplifiers maintains that the best bass he's ever heard came from Lamm ML2s. Having owned those amps, I have an idea of what he means -- low frequencies that are deftly integrated into the sonic spectrum, bass that sounds realistically rendered and paced, not calling attention to itself through pomp and bluster. The ML3 Signature underscored the notion that the bass region doesn't have to be a traditional weakness of SET amplifiers, offering depth and power for sure, but also an unerring transition to the midbass and above. This serves rock well, where throbbing and pounding convey the music's energy, and the rock I've been listening to lately has been on LP.

I bought Donald Fagen's classic The Nightfly (Warner Bros. 23696-1) at a garage sale years ago. It didn't cross my mind then that I would return to analog playback; I simply couldn't let the album sit there for 50 cents and not pick it up. The ML3s portrayed the bass line on "Ruby Baby" as a silken purr, not so much sounding guttural as accentuating the rhythmic jump of the song. Curious, I pulled out The Nightfly Trilogy (Reprise 9 43325), the exhaustive boxed set of Donald Fagen's remastered solo albums. On CD and especially DVD-A, the bass line of "Ruby Baby" took on a different character -- sounding almost synthesized. The liner notes credit Anthony Jackson as the bassist, and he plays electric bass. Still, the Lamm amps made this distinction plain, though its source -- whether a matter of digital vs. analog playback, or original mastering vs. remastering -- is a mystery to ponder. The LP's bass line was more "in the grain" than the CD's or DVD-A's, more in keeping with the music's rhythmic intent.

The midbass was enticing, possessing a dollop of fullness and warmth that never overstepped what's happening above or below. My first exposure to this came at CES in 2007, when I listened in mono -- one speaker, one amp -- to "Contrabajeando" from Daniel Barenboim's CD of Argentinean music Mi Buenos Aires querido (Teldec 0630-13474-2). The creamy texture kept me glued to my seat, as did the grunt the bowed bass displayed, much of whose energy on this cut resides in the midbass -- 200Hz and above. Some tube amps do the midbass well, getting points for their lowest frequencies because of it, and others don't; the Lamm ML3s set a new standard for realism in this often-overlooked (overheard?) range.

Nothing is overlooked in a tube amp's midrange, and the ML3 Signature's was wonderfully animated -- absolutely bursting with presence and life, conveying subtle nuance with, again, a deft touch. But it is the sheer amount of musical information conveyed and how it's presented that listeners will notice. There is an intricate dance between resolution and naturalness, the sense that the amps are laying bare all musical detail in a very graceful way. This can make solid-state amps, even very good ones, sound crude and uninvolving by comparison, and it advances even further what SET amps traditionally do best.

If you're thinking what I first thought when I discovered this skill of the ML3 Signature amps, you will head straight to your jazz-vocal section, as female vocal is a definitive midrange test. Hope Waits' name is a grammatically complete sentence, and her self-titled debut CD (Radarproof RPR1019) is an impressive statement on her contemporary jazzy music à la Norah Jones, to whom I'm sure she is compared (no one could hear "Drowning in my Own Tears" and not think it's Norah Jones). Perhaps because of her name, she covers a Tom Waits song, and an interesting choice it is: "Get Behind the Mule" from Mule Variations (Anti/Epitaph 86547), one of Waits' (Tom, that is) more fractured collections. She gives it a good stroking, stressing a sensuality that either Waits (Tom again) ignores in his growling version or she has forced on the music. Whatever the case may be, it works, and the Lamm ML3 Signatures bring out all of the steaminess amidst a drum-driven, funky arrangement. You'll want to repeat the a capella opening over and over. It's breathy and pure -- perfect musical fare for the ML3 Signatures.

The amps' transient response had leading-edge speed and definition equal to that of a light-on-its-feet solid-state amp, and when this was mixed with that bristling midrange, the effect on the music was thrilling -- refinement to the extreme. While attack in the treble region -- from instruments as diverse as electric guitar, trumpet and violin -- is most obvious to our ears, it also occurs much lower, in the midbass and even in the fat part of the bass region. The ML3s captured it up and down the frequency spectrum, firing out notes that were distinct through their entire duration. An album that brought it all together particularly well was the Wood Brothers' earthy Ways Not to Lose (Blue Note 0946 3 43120 2 8). This spare combination of guitar and upright bass with drums mixed in on a few tracks was recorded with utmost naturalness and space -- in other words, it sounds great. With seeming equal amounts of coherence and fidelity, the ML3s brought this music to life in my listening room, sounding delicate in the treble, and powerful in the bass -- with no spotlighting or recessed areas. This music flowed from the Wilson Audio X-2 Series 2 speakers, which created a soundfield that was wall to wall and, more significantly, from the floor to nearly the ceiling. This gave the upright bass truly lifelike stature, and each note of the guitar was carved out from the others by the amps' handling of transients.

In so many ways, in fact, the ML3 Signature amps are an ideal mate for the biggest Wilson Audio speakers, the two reinforcing what each does best. The latest iteration of the X-2s are midrange-detail machines, conveying whatever is fed to them with unerring honesty. They don't prettify, being closer to ruthless than forgiving, though not really being either one. The Lamm amps have more than enough power for the speakers -- the less powerful ML2.1s drive them easily too -- and when the amplifiers and speakers lock on to the signal, it's hard to believe that reproduced music can get any better.

And then it does get better. Amps like the ML3 Signatures, which use hard-to-find tubes that have no substitutes, don't really lend themselves to trips down the new-old-stock path. However, Vladimir Lamm has a small cache -- about six sets -- of some copper-plate GM70s. The amps come stock with carbon-plate GM70s, and it is with these tubes in use that my comments about the amps up to this point have been written. The copper-plate tubes are a different breed from the stock tubes, increasing the leading-edge speed and midrange detail just enough to make clear their superiority. They sound more spacious too, never a bad thing with a tube amp, and a very good thing when an amp is single ended. While Vladimir Lamm is reluctant to sell these tubes, ML3 Signature owners who won't accept anything short of the very best sound possible should contact him. I shudder to think what a pair of these tubes -- when Vladimir has only six -- will cost.

Comparison cornucopia

In case you were wondering, I didn't have another amplifier in the six-figure price range lying around with which I could compare and contrast the Lamm ML3 Signature, but if you've read my reviews, you know that I have written about many distinguished tube amplifiers, all of which cost a great deal less than the Lamm amps. The ones the stand out most -- for me and perhaps for you as well -- are two that we named our Edge of the Art products for 2007: the Atma-Sphere MA-2 Mk III monoblocks ($32,800 per pair) and Convergent Audio Technology JL2 Signature Mk 2 stereo amp ($16,995). And what comparison of the ML3 Signature would be complete without consideration of the Lamm ML2.1 monoblocks ($29,990 per pair), which used to be at the top of Vladimir Lamm's amplifier line?

If you're parsing these amps in your head, you already know that they are very different, even though they all use tubes. Like the ML3 Signature, the ML2.1 is a SET amplifier, but it outputs 18 watts from a pair of 6C33C tubes. The Atma-Sphere MA-2 Mk III is a fully balanced output-transformerless (OTL) design that delivers a whopping 220 watts from a forest of 6AS7 tubes. Finally the CAT JL2 Signature Mk 2 is a push-pull triode amplifier that delivers 100 watts per channel from eight 6550s, though its perceived power output is much greater.

In terms of sound, these amps are as different as their topologies and tube complements would suggest, except for the two Lamm amplifiers, which understandably share a family resemblance. While the ML2.1 is an uncommon SET amp because of its ability to be used with more speakers than its competition, the ML3 Signature takes this to another level. Except with insensitive exotic speakers -- ones without cones and domes -- the ML3 Signatures should work, though it's with speakers whose sensitivity is 90dB or above that they sing. The ML2.1 is similarly a full-range SET amp, one whose ample midrange glory doesn't come at the price of droopy performance at the frequency extremes. And it is through the midrange that the ML2.1s really show that they are worth consideration next to the ML3 Signature -- the trademark Lamm naturalness and copious detail are in full force. Down low, too, the ML2.1s impress, with a bass region that simply flows out into the speakers with no obvious issues.

But there are similarities and there are improvements, and the ML3 Signature amps are firmly rooted in the latter. They simply offer more -- more midrange detail, more bass depth and liquidity, more transient speed and definition. The change from a different company's amplifier to the ML3 Signature may be startling, but transition from the ML2.1s to the ML3 Signature will seem completely understandable; the former will get you ready for the latter -- like a fireworks display that leads to a grand finale that absolutely fills the sky with light.

The Atma-Sphere MA-2 Mk III also has an impressive midrange, but it's very different from that of the ML3 Signature. With the Atma-Sphere amp, it's transparency, the proverbial missing window between the equipment and the music, that will draw the "oooh's" and "ahhh's." This is even more attention-grabbing than the ML3 Signature's midrange detail. The tubes driving the speakers with no output transformer in the way is something you have to hear to appreciate. The Atma-Sphere amps are certainly more powerful than the ML3 Signatures, but not noticeably so unless you clip the Lamm amps. The Atma-Sphere amps also handle transient attack in a decisive manner -- without blur or rounding. The bass of both is good for tube amps, but the ML3 Signature's low frequencies are a little better integrated into the spectrum of sound the amp produces.

The CAT JL2 Signature Mk 2 is in the middle in terms of power -- 100Wpc -- and it's a stereo amp, but that one chassis can pound out the music with greater authority than most amps I've heard -- and better than any tube amp. But it's not about sheer power, providing finesse and a big, meaty midrange. The ML3 Signature doesn't keep up with the JL2 Signature Mk 2 in terms of output power, perceived or real; the CAT amp might be suitable for any speaker on the market. But the resolving midrange of the Lamm amps does make the mids of the CAT sound overly juicy, obscuring some of the detail the Lamm amps retrieve with seeming ease. The CAT amp has all of the earmarks of its triode nature and none of the limitations of that operating mode, while the Lamm amps build upon some of triodes strengths, especially the midrange, while ceding no ground at the frequency extremes.

The real winner in this lineup is the Lamm ML2.1, which stands on its own between the Atma-Sphere and CAT amps, has sonic resemblance to the ML3 Signature, and is in the middle of the pack in terms of price. If the ML3 Signature has you both crazy with lust and lamenting your financial state, the ML2.1 is a sane alternative, although in this case sanity is all in the mind of the beholder.

Back to "worth of sound"

Sonically, the ML3 Signature lives up to its towering position in Vladimir Lamm's amplifier line. I've heard no amp with a more detailed and graceful midrange. The fact that it comes in the company of truly extended and complete bass and treble, along with the ability to drive a wide array of speakers, points to this SET amp being more than a different breed -- a new species. Headbangers need not fear the ML3 Signature's mere 32 watts, especially if the amps are paired with Wilson Audio X-2 Alexandria Series 2 speakers or a speaker of similarly high sensitivity. With the latest Wilson Audio X-2s, these amps perform as a single unit, the speakers providing the ultimate conduit for the amps' sound.

However, especially in trying economic times, the Lamm ML3 Signature occupies a very small market -- even smaller than similarly priced speakers, whose sheer size helps them make a case for their high cost. In discussing the value quotient of a product with a price as high as that of the ML3 Signature, then, you have to take into consideration not only the product's cost but also what a potential owner gets in return. The cost of the ML3 Signatures is high, and the return is also high -- in important ways, higher than any amp I've heard. And let's be honest -- people buying these amps aren't part of the shrinking American middle class; they're funded and landed, able to absorb the cost of these amps as easily as I can the cost of a slice of pizza. That will make the ML3 Signature amps right for some very wealthy people and objects of fantasy to the rest of us. So it goes. Jealousy will get you nowhere.

One person who visited and heard the ML3 Signatures in my system put it best: "I want them. I can't afford them, but I want them."

...Marc Mickelson

Lamm Industries ML3 Signature Mono Amplifiers
$139,290 USD per pair.
Warranty: Five years parts and labor, two months for tubes.

Lamm Industries
2621 East 24th Street
Brooklyn, NY 11235
Phone: (718) 368-0181
Fax: (718) 368-0140

E-mail: lamm.industries@verizon.net
Website: www.lammindustries.com

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