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Vladimir Lamm interviewed by Sergei Taranov, Editor, AUDIO magazine (Russia)
at the HI-FI'96 Show (Waldorf-Astoria, New York City, May 30-31, 1996)

Published in AUDIO magazine (Russia), Vol. 4 issue 9, 1996 (translation)

1

AM: In Russia, you are known to many by your articles in "Radio" magazine; you were also known as a Chief Designer of the Lvov Radio-Electronics Co. where "Amphiton" amplifiers, in particular, had been designed by you. Many know that you had emigrated to the U.S....

VS: For me, things had not turned out quite favorably. While waiting for the U.S. entry visa in Italy, I broke my ligament playing tennis (I was a professional table tennis player). A knee operation in America, where I arrived shortly afterwards, was not successful; two following years had not been too productive for me. But, as they say, there won't be fortune if not for misfortune: during that time I had been working on my English and began sending resumes to high-end audio companies. However, I discovered that those companies needed mostly technicians, as their own design philosophy had already been formed and crystallized. Eventually, I found one company, "Madison Fielding, Inc."

Originally, they invited me to work on simple designs but I offered to contribute high-end designs; they accepted. As a result, I became a partner in the company. My first implemented designs were power amplifiers model M1 and M2 which were exhibited for the first time at the Summer CES in Chicago, IL in 1993. For us, it was quite a sensational presentation (M1s were drivingWilson WATT/Puppy2); the tandem was labelled "the best sound at the Show" (you probably have this information from the materials I sent you).

However, my partners at Madison Fielding, Inc. were not the "high-end" material; in other words, they did not fully grasp what this business entailed. It was only after that Show that I realized that the company had no intention of starting production. Although I had practically no resources for doing so, I left "Madison Fielding, Inc." to establish my own company which began its operation two months afterwards.

That was in October, 1993. Now, this is my sixth Show. During the past three years I had completed and implemented into production a line-level preamplifier model L1 with a fully balanced circuitry. It is a very interesting model -- I use superlinear high voltage MOSFET transistors in the front end and +350V vacuum tube voltage regulator. Right now, I have a couple more preamplifier designs (not implemented into production yet) which are less expensive than the L1...

AM: What technical solutions characterize LAMM designs?

VS: I had been working for a long time on the question of why one piece of equipment makes good sound and the other does not. This question is as old as the world itself. I took the path of psychoacoustics and developed a number of mathematical models which manifested a more or less close approximation to reality (fortunately, back in Russia, I had a whole R&D department at my disposal). Those mathematical models were described by differential equations; specific correlation systems were developed. Using this information I obtained the electronic models of processes.

AM: In other words, you created something akin to the analog computer?

VS: Correct. As a result, I ended up with a very limited number of topologies which can be used in audio applications. Now I make audio equipment using those results. As a rule, I do not go through listening tests of the designs I create: when design is finished I make one listening test for control purposes...

AM: Simply speaking, you know the results beforehand?

VS: I do. Each model is designed absolutely deliberately with predetermined and predictable characteristics.

AM: Let's say, a Japanese reviewer N. comes to you and says that everything is great but he would like to have a deeper soundstage. Do you know what you will be doing?

VS: Yes, I know what I will be doing: making a soundstage deeper (laughing). I set certain requirements for each of my designs and implement them -- it is confimed by practice. In particular, the amplifier we are looking at -- model M1.1 -- is our flagship design in a solid-state line. It operates in pure class A mode and its topology features no feedback. We use high speed power MOSFET transistors.

I had spent a lot of time figuring out how to make the output stage work properly. It had been difficult because I use no feedback. As a result, even no servo system is employed and my amplifiers are thermally absolutely stable: output DC offset is no more than 10-15 mV in the temperature range between 10-45°C ambient--this is a very good result.

AM: Is there anything at the output, for instance, inductor?

VS: No inductors. The output impedance of an amplifier is about 0.18-0.2 Ohms, linear from 20Hz to 25KHz; in other words, the active component is overwhelmingly dominant in the output impedance. That is one of the reasons why the amplifier behaves as a magnifying glass with many types of speakers, making clear what is going on in a system as a whole because the amplifier is practically neutral itself. Besides, these amps can be used as welding machines (in other words, the amps can function even under short-circuit conditions). The input current is limited only by a line fuse, the value of which had been calculated to activate it, should the output power exceed about 400-500 Watts. The front end topology is quite interesting--if I were to simplify its description I would say that the input is a cascode differential long-tail pair utilizing matched p-channel FET transistors and the high voltage p-channel bipolar transistors; the so-called Wilson current mirror is used as a current source; 6922/ECC88 vacuum tube is used in the second stage; the third stage is a single-ended high-current buffer on n-p-n bipolar transistors utilizing a current source. At a first glance, it is quite simple; however, as I mentioned before, these circuitries have been developed according to the electronic models I had already created. Here I use a quite simple, from my point of view, biasing circuitry that also provides an excellent thermal stability of quiescent current of the output transistors. I do not know who else utilizes such circuitry. I had spent a lot of time solving this issue; of course, there exist standard solutions for resolving this problem, but these types of solutions are quite costly and not always very effective. Besides, my amplifier is expensive as it is.

Other features that add to the proper functioning of amplifiers include a soft-start circuitry. For the first 2.5 seconds voltage is not applied to the filter capacitors since the big caps would blow any power supply while in a transition mode (which leads to a short circuit); therefore, a soft-start circuitry is used; next, time relays kick into operation.

AM: Through the resistors?

VS: Three power resistors connected in parallel are, in turn, in series with the mains. I use a very serious protection circuitry, with the delay time of one minute, to allow the initial warm up of the amp. Should something go wrong inside, the amp turns off and waits to see what happens next. If nothing happens, it turns back on. Let me demonstrate how the delay works (demonstrates).

As has already been admitted by the experts in the U.S., England and Japan, these amplifiers, beside other qualities, have an absolutely unique capability to reproduce natural bass, although these are not the DC amplifiers: there are coupling capacitors between the front end and output stage...

AM: Which stage of your Soviet biography do you remember today from the position of a high-end American designer and LAMM President and Director of Engineering?

VS: In 1963, I got admitted to the Lvov Polytechnic University, Department of Electrophysics, where I majored in solid-state physics, semiconductors, etc. Graduated in 1968 with a research profession of an engineer/electrophysicist and designer of semiconductor devices. Conducted fieldwork and was working on an M.S. thesis at the Kiev Institute of Semiconductor Devices of the Academy of Sciences of the Ukrainian S.S.R. Did research on electro-luminescence and was involved in making electro-luminescent devices utilizing silicon carbide (SiC). Completed a write-up of an M.S. thesis about 4-5 months prior to the scheduled defense and was assured of a position at the Institute upon defending. I had already started sorting out ideas about my future Ph.D. dissertation, but in 1968 I got drafted to the Army and this process was interrupted. (Having been born in a miserable year of 1945, I belonged to a generation that was turned into a kind of an experimental scapegoat on which various social structures were being tested: first a 7-year primary schooling, then an 8-year schooling, special polytechnic education, 11-year primary schooling...When I was still in college, the Army service was not required for college graduates--upon receiving a degree, the graduates were also conferred a military officer rank which eliminated the need for them to serve in the Army. Then, just prior to my graduation, a newly implemented idiotic Soviet "law" went into effect making serving in the Army compulsory for all young graduates...)

When I came back to Kiev after a two-year military service I learned that the position I had been promised before my military service was already filled. I then returned to Lvov and started working at the Lvov TV factory "Electron". In reality, this factory was a major defense organization. My primary work there was concerned with closed-circuit TV systems. Later on we started working on high-definition TVs--have you ever watched on TV the Center for Space Flight Control in the town of Podlipky, seen all those desks with monitors? That was our design. We also worked on electronic equipment used for instruction and training of military and civil pilots and astronauts.

At one time the factory got a hold of a foreign TV-system with image scaling that was performed via optical methods utilizing highly complex optics. We had been assigned a task of creating the same system but with a scaling factor of 40 which had to be maintained on the display to keep up with changing of the television raster and with the characteristics that had to remain constant. I started checking around...

AM: This was also a military order?

VS: Yes. ...I had visited the Central Aero and Hydrodynamics Institute where the research was being conducted on a similar topic. The researchers there explained to me that such issues could not be resolved by electronic means (the computers had been a rarity in those days), only by optical ones. In the Moscow Television Research Institute, similar systems had been implemented with scaling of only 5 times, and I needed a 40-times scaling. I took on this task, maybe because I was too young and did not realize what was involved in it, but I finally solved this problem. I quit "Electron" a couple of years afterwards, just when various R&D companies for consumer electronics (and especially audio electronics) started opening up throughout the USSR. I turned to the topic I was most interested in--audio. Worked in the position of a Chief Design Engineer at the R&D Department of a large electronics company in the city of Lvov; The Department was involved in design of consumer electronics. Some of the projects I oversaw and participated in were: design and implementation of various power amplifiers, control and phono preamplifiers and equalizers for consumer and professional use; investigation and analysis of the world audio market; prognosis and formation of the promising avenues in the development of consumer audio equipment. "Amphiton" amplifiers that I had designed and implemented into production are just an external part of my job--it is of no interest. At the same time I had been "making myself" or, in other words, kept asking myself questions. When I was unable to answer them, I would embark on a learning crusade. Learning is a life-long process for me.

First, I kept asking the so-called simple and naive questions. For instance, we have three amplifiers: one with a 1-2% distortion, another with a 0.1% distortion and yet another with a 0.001% distortion. All three are heard through a speaker with, let's say, about 5% of its own distortion. Theoretically, we shouldn't hear the difference, just a "signature" of the speaker. But the paradox is that we hear the difference between these three amplifiers perfectly. The answer to this question is not that easy: it took me a few years to understand the nature of this effect. There is no place where you can learn how to make the sound--you can confirm this with any serious audio designer, or just any designer who has been able to create a reasonably wellsounding system. I repeat again that I have been learning all my life. I had an opportunity to conduct an enormous number of experiments or, in other words, check my theoretical hypotheses and calculations and narrow the number of topologies capable of producing good sound until I obtained the desired results. As strange as it may sound, a big help in getting the results was my eight-year-long wait in the Ukraine for an exit visa, although this period was full of problems related to my status of a "refusenik" (persecution by the police and other problems). I had time to sort out a lot of ideas and results. Based on the electronic modeling of a human hearing mechanism and having arrived at a limited number of electronic topologies that describe our hearing perception to a greater or lesser degree, I created a number of working prototypes. I purposefully created various systems: solid-state, hybrid, and vacuum tube ones. In the end, I came to certain conclusions which I have been able to implement only here, in the U.S. Of course, it would be impossible for me to do anything here without years of previous thorough research--R&D is very expensive here. There are no grants available for this type of research, the government is not involved, various financial groups that sponsor research are not interested in this type of venture--financially, this is not the kind of business they would be investing in. I was able to realize my ideas with the least amount of expenditures only because back in Russia I had tremendous experience in implementing my own designs into production and their maintenance. I am familiar with an entire cycle: from an idea to a finished product. (By the way, back in Russia I was in charge of a number of very serious research projects and my job involved finding specific solutions to a range of problems, from research ideas to their implementation.) Here, in the U.S., I do everything myself.

AM: By the way, what do you think about domestic vendors of parts you use in your designs? Was it long before you found vendors? What is the quality of parts?

VS: As I mentioned before, I became a partner at "Madison Fielding, Inc." and got to know certain vendors over time. People don't talk much here, no one teaches you: if you got yourself into something you have to handle the consequences on your own. The only thing that I received assistance with was the transfer of literature, catalogs, component data to my home, in order to give me an opportunity to work out of home when necessary. "Madison Fielding, Inc." was 50 miles away and I did not have a car at the time; I had to do all the commuting by train.

1


AM: Let's talk about equipment measurements. There are two points of view on the subject. First is that measurements do not mean anything other than (roughtly speaking) quality of the equipment--we need measurements only to make sure that everything works properly. Second is that, at this point, we don't even know what to measure. Do we need measurements at all?

VS: Of course. The measurements describe objective processes and phenomena. In a way, I solved this riddle: I achieved the correlation between the quality of sound and formal measurements, or at least those measurements which are formally present in every national standard and which are made public by designers. Of course, when one looks at the measurement results presented in a graphical way, one should have at least a basic understanding of a topology of the measured device and understanding of which formally measured parameters are critical to one or the other specific schematic solution. And it is absolutely necessary to know the types and values of feedback (if any) utilized in a given device. In other words, one should know what to measure. When a person sees formal measurements of a piece of equipment--even if he doesn't know anything about it--he can say a lot about it by looking at the measurements, as long as he has an understanding of a subject matter. Usually, electronic engineers think that audio electronics is a passing stage between an entry level and professional electronics, although in reality one should get into audio electronics after all other areas of electronics have been mastered.

As a rule (and I don't know of any exceptions) a person who is involved in design of at least high-end audio equipment either has to be a musician or at least know the sound of a real orchestra. This is a trivial observation but it is true.

AM: Let's talk about assessment of sound quality. In general, there exist just a few fundamental approaches in this respect. One of them is quite obvious and clear--it is when a person compares the reproduced sound to the one of real instruments in a natural setting. Another is the one popularized by Mr. Qvortrup who claims that we know nothing about a recording process and that the only way to understand anything is to listen to an enormous number of records, one after another, and watch how the difference between them is revealed. If the difference is three-dimensional, then the system is transparent; if it is not, then the system is not.

VS: What if it IS and IS NOT simultaneously, as so often happens in life? What are we to do then? (laughing)

AM: But, still, what is your opinion?

VS: I have already said that a person should either be a musician or listen to live music on a regular basis, and to also remember one thing: that we are the perceivers and that the mystery is beyond us. The only thing we can do (using a servo system for analogy) is to choose a reference point based on live music and compare everything else to this point...Then, this question does not even arise.

This is an old issue, an issue of inner culture and education. We live in this world, we have certain musical instruments, we know certain music by certain composers--and we are limited by this information. Why, then imagine supernatural problems and put a heavy burden on oneself? It is important to accumulate "baggage" first--that is, to know how the real orchestra sounds. The rest is a question of classification and creation of certain hierarchical gradations. The problem of sound quality assessment is almost completely solved in the first 10-15 seconds of listening at the intuitive level. Any experienced listener knows that the first minute of listening is the decisive one, and the rest is simply putting the perceptions of that one minute into words; it becomes a question of terminology and method of communication.

As human beings, we perceive sound on various levels: conscious as well as subconscious (or intuitive). We perceive sound not just with our ears, but with the whole body. I had been seriously involved in sound perception issues and developed a very specific criteria for myself in this regard.

We have to listen only to the music; the equipment should move into the background, disappear. We must listen to the music--I think, this is the only reasonable approach. Right now, I am not talking about the questions of objective knowledge and so forth.

From my point of view, the ideal review is when an audio reviewer has nothing to say. Quite naturally, such reviews do not get published(!), as the reviewers must earn their bread, and the readers must get their entertainment; but the ideal conclusion should be: "I have nothing to say..."

1

AM: What are your plans for the near future? What new equipment are you working on?

VS: In the of LAMM AUDIO LABORATORY® products (solid-state and hybrid line) I have completed the design of a dual-mono power amplifier model DM1, with a retail price of approx. $9,700. Aesthetically it will look very similar to the M1.1, with a wider front panel (19 inches in width) and two heatsinks on each side. This is a highly biased A/AB design; the topology and physical design are similar to that of the M2.1, with an exception of a tube stage with accompanying elements--filament voltage regulator and so forth that are quite expensive--which will be replaced with a high voltage MOSFET. In other words, the amplifier will be a pure solid-state design. As I said, the design has been completed, a prototype built, and what's left is to make the PCBs and start production. I might make a small preproduction run at some point in the near future. Based on the DM1, I will have a more affordable stereo amplifier, at about 60 Watts per channel; it will be the size of my preamplifier L1. This stereo amp will also feature high-speed MOSFET transistors in the output stage with no overall feedback, and topology and design philosophy similar to my other designs. It will have the same "recognizable" LAMM sound. This model will retail at approximately $4,000-4,500. I will also have a simplified version of the L1 that will retail at $2,900-3,100. With this, I will draw a line to my solid-state designs for the near future.

I am a "vacuum tube" man by nature. There is no limit to what can be done. I even established a new company LAMM INDUSTRIES, INC. which manufactures vacuum tube equipment. I have practically completed the design of a single-ended 8-Watt amplifier on 300B--this is more or less tribute to the latest fashion. I also have a design of a push-pull amplifier on 300B, operating in class A, but I would rather not start its production just yet, as I plan to start the production of an 18-Watt single-ended amplifier model ML2 shortly. And the crowning touch of all will be a single-ended amplifier on a Russian tube GM-70.

I have practically completed the design of two more models of more affordable power amps on vacuum tube 6550 (which is, by the way, from "Svetlana"); this tube has gained a fairly good reputation, especially its latest modifications. One design is a 70-75-Watt stereo amplifier, with two 6550 in each channel; and the other is a 150-Watt monoblock, with four or six 6550 tubes per channel. I will also have quite an original (probably even unique) model of a vacuum tube preamplifier.

To sum up, I will have three single-ended models: 8-Watt on 300B; 18-Watt model ML2, and 30-35-Watt one on GM-70. Right now, I have completed a design of quite a fascinating preamplifier which, I think, will become the reference (for some time to come) in terms of sound quality. By the way, it will have a Russian tube 6N6P that has certain interesting characteristics.

What I'm showing you now is a photo with a phono preamp--it is practtically ready, I'm just working out the details. It will be quite an expensive piece, and there is a relatively limited, although steady, market for such equipment. As strange as it may seem, in spite of the cornucopia of phono stage models available on the market (solid-state as well as vacuum tube ones), serious audiophiles still feel the lack of a real phono stage that would be practically neutral and satisfy all requirements. Many of my customers and dealers keep asking when I would have such a phono stage.

It is very difficult to do everything simultaneously. The key is in increasing our sales. Export is important, including Russia, although up until recently I have been very skeptical about trying that. However, I now begin to think that Russia might become an interesting market in terms of audio. One of my goals is to get to the Russian and Ukrainian markets and other regions which had become independent. It is only a question of time when all this outrageous money and foolishness that are characteristic of today's Russia transform into respectability. From the children of all those who had at one point been slaughteered, shot, put to prison and destroyed, there will emerge (of course, under a different guise) a new class of people. Natural sorting out always takes place. Equal civil rights do not presuppose equal individual capabilities; each individual is made in a certain way, each individual needs certain things--it has always been like that and will always stay like that.

I'm involved more in technical aspects than in political issues. When one leaves Russia, the unhealthy interest in the so-called politics goes away, and other aspects of existence come to the fore, those aspects which did not even touch our paranoidal mind at the time when all of us had been deprived of our individuality.

Many dealers and designers ask me what I think of digital technolgoy and whether my company will every go digital. My answer is very simple: this field is not a terra incognita for me but I consider myself quite an ordinary engineer in it. I always conform to my philosophy of not becoming involved in things which many people are able to do. In order for me to achieve a level of art in digital technology I have to live one more life. First of all, it is a little too late to get into this, and, second, my heart is not in a digital domain. I have always tried to do what I can do best and have paid a tremendous price to be left alone in order to do what I love.

I'm an "analog" man by nature and my mind is "analog." I would not want to exchange the best digital system for the best analog system. Simple listening tests of digital and analog systems of comparable level make clear that there is nothing to talk about (fortunately, there is a great number of high quality LPs, and CD reissues of those LPs that make such tests possible). Digital technology by itself is not so bad; it is convenient in terms of working with recorded material (remote control operation, ease of choosing any track on a CD, choice of various programs and so forth), but if you want to "fly away" and have serious listening, there are no two opinions about it.

The market situation here is very interesting: there are many worthwhile things, along with quite a number of cheap promotional tricks. Take, for instance, an amplifier of class A operation. The fact that the designer decides to create an amplifier operating in pure class A (especially high power class A amp: over 50 Watts) automatically presupposes that it will be fairly expensive just from the standpoint of physical implementation. I leave out the issues of sound quality--everything depends on who and how will be designing such an amplifier. Here, in the States, the fact that the audiophiles-at-large know only that class A is a good thing gets abused: all too often anything slighly warmer than liquid nitrogen is declared class A. Because the consumers know that class A operation is a good thing, certain manufacturers, in order to promote their products, use the term "class A" to describe amplifiers operating in class AB or even B. As a result, a problem arises with price formation for the amplifiers that actually work in class A. Take, for instance,my ML1 amplifier. Using audiophile terminology, its class of operation can be described as highly biased A/AB. However, I could quite comfortably label it an amplifier operating in pure class A. And, of course, it would be much easier to sell it then. However, this is plain cheating. In reality, should the ML1 be a pure class A amplifier (the same 80-90 watts of the output power with a frequency range of 20-20,000Hz) done honestly and properly, the cost of its building would rise significantly. But in this case, and it would be very, very difficult to sell it, although the jump in sound quality would be significant. And so, we are back at square one.

When a piece of equipment is designed properly, so to speak, then formal technical data describes and characterizes it quite comprehensively. You know, for instance, that single-ended amplifiers (especially those on vacuum triodes) have a weak spot: roll-off at the low and high frequencies because of an output transformer. For the absolute majority of single-ended tube amplifiers, frequency response characteristic is specified at the output power of 1 watt. What's going on with the frequency response at the nominal power is a "black hole"...-- and this is one of the most important parameters of any amplifier, and especially single-ended one. My single-ended amplifier model ML2 maintains a frequency response from approximately 16-20Hz to 60-80KHz (exact values will be specified when production begins) at the nominal power. And I guarantee the constancy of harmonic residue shape at all frequencies in the range of 20Hz-20KHz (again, at the nominal output power!). There hasn't been anything like that on the market among the single-ended amplifiers.

Images are courtesy of AudioMagazine (The Hi-Fi Journal) of
St. Petersburg, Russia. E-mail:
ampost@comset.net