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Jürgen Straussman | D/AmP Audio GmbH
Teltower Straße 1 | D-14109 Berlin

tel.: +49 (0) 30 80 58 61 20
fax: +49 (0) 30 80 58 61 29


Country of origin: Germany

hat do we need audio shows for, I ask you? I hear the question over and over again from the manufacturers and distributors alike that - yet! - participate in them. I try to answer the question honestly and to the best of my knowledge. I also write about this in my show reports. I might as well talk to a brick wall. Nothing, niente, punto. And yet there is a definite answer that cannot be ignored: if they cannot see us, they won’t write about us. Those that are not written about usually slowly disappear. Unless they opt for alternative promotion strategy, which is not easy and does not guarantee success. It is all about promotion and about gaining product interest among as large a group of people as possible – both potential customers and the press, some of which may also become users of a given product.
If, for example, Straussman hadn’t showed up at the High End 2013 in Munich, I wouldn’t have heard of this manufacturer. It wouldn’t have received “High Fidelity” Best Sound 2013 award (see HERE). And I wouldn’t have met Jürgen Straussman, its founder, head and chief engineer. Nor would I have visited him in his Berlin home.


Trips to visit interesting companies, places, countries and meetings with interesting people are all part of journalism. The most pleasant part. Provided we like travelling and have time for it. Which is not necessarily my cup of tea. I do not really have time for such trips; I would have to take it away from my family and to give up a few reviews. And while I like travelling, it's only with my family. Hence I face the catch 22 situation, which is why for some last 10 years I haven’t accepted any invitations to conferences or to visit factories and companies. I know that it limits my knowledge and experience, but I accept it and I'm fine with it. How did it then happen that in the middle of August 2013 I accepted Jürgen’s invitation to Berlin, where I spent a few days? I have been looking for an answer myself and came up with a few ideas that can shed some light on this matter. First, Straussman components struck me as extremely interesting. In Munich the company presented a phono preamplifier and amplifier, or actually a system that consists of three parts – the central module with volume control and two amplifier modules. The units are tube-based and feature no single capacitor in the signal path. Yeah, that’s right. The second reason could be the designer himself. While we did not meet in Munich, shortly after the HF publication of my coverage from the show I received a nice email with an invitation to visit the company and listen to some vinyl, being Jürgen’s basic “diet”, in a better surrounding than that during the show. I declined politely, thanking for taking me into account; he could have chosen anyone else. So what happened that I came, I drank beer, I listened and discussed, and I met Oliver von Zedlitz, the owner of KlangwellenManufaktur (see the review of his Cantano turntable HERE )? Well, it just “happened”. Not only that, but I actually flew over to Berlin with my family and we had plenty of time for sightseeing and excursions. No, not at Jürgen’s expense, just to be clear.


The Straussman system has the already mentioned Cant turntable as the source. Hence, its main component is the MC-Phono 2010 phono preamplifier, which is equally expensive as the rest of the system (read: very, very expensive; final prices are not yet confirmed). But it is the amplifier, the idea behind it that seems most interesting to me.
The company, which part is Straussman, is called D/AmP Audio, which is a rather “telling” name. It was founded in 2009 as a branch of Laurens Organ Company, where Jürgen indulges his other passion for restoring the Hammond organ. He has two representatives of this genre at home, alongside a grand piano. But it is the Hammond organ and records featuring the Hammond that he is really excited about. He delved so deeply into the subject that he now offers upgraded amplifier modules that make the organ sound as they did while leaving the factory in the 1960s. His next idea was upgrading CD players, for which purpose he designed discrete D/A converters with an active output stage that was powerful enough to drive the speakers directly. The whole circuit was mounted on a characteristic polygonal circuit board. Hence the name D/AmP.

The results were very promising, but it was ultimately vacuum tubes that became the central component of the new amplifier, or actually a ‘system’ as it is referred to in the company literature: Holographic Music Reproduction System (HRMS). The control center unit handles all control functions and features an integrated proprietary D/A converter (not based on any ready-made DAC ICs). Interaction with the user is via a large touch screen user interface, duplicated on a tablet that is used for remote control. The analog signal is fed to the monoblocks that, while nominally being (together) an integrated stereo amplifier, do not work without the control center. If we use the DAC, there is another cable to connect to the amplifier modules; the whole circuit from input to output has a balanced topology. During DAC development the best result were achieved with direct signal coupling, without any capacitors. Applying this same principle to the tube-based amp proved to be rather difficult, but eventually successful. The E-50 amplifier operate in Class A and feature the 6C33C Soviet-era power triodes, sometimes referred to as “horny devils”, to deliver 50 watts into 8 ohms. Modular design is used throughout, which means that any section can be upgraded for a newer version, once it’s available. This promise can be found on the manufacturer’s website and it looks to be a serious approach to the subject matter, rather than a marketing gimmick. Both in- and post-warranty customer support is as important for Straussman as the sale itself and it’s reassuring that after buying such expensive products you can count on professional and dedicated support by the manufacturer. Although in the high-end this should be as natural as breathing, it often seems a truly endemic phenomenon.

That was the person at whose door I arrived one morning. Before we broke the ice during breakfast in the back garden of an Art Deco-style villa, I already met two pet cats, Mau-Mau and Timmy that bravely accompanied us during the auditions over the next few days. A villa in Berlin? In its historic western part? And with a large garden? Not to mention the Hammond organ in one room and a grand piano in another (I should actually call them “chambers”). In order to grasp what kind of person we are talking about, I suggest you read the story of Jürgen Straussman’s life and career, as told by himself. WP


I was born on December 22th, 1954, in Berlin. Although I do not believe in horoscopes, I learned that people’s character DOES depend on the date they are born. I am a Capricorn with Capricorn ascendant. I’m also a Horse in the Chinese zodiac, which describes a similar character to the Capricorn. So you can say I am a triple Capricorn with all its characteristic, both good and bad. Be that as it may, this helped me along the path of life.
My father, born in 1919 in Ornontowice, located in the Silesia region that is now part of Poland, was a typesetter by profession. He was wounded during the WWII and his lung was damaged. After the war, because of lead used in typesetting he was not able to work anymore in his profession and became a violinist in the Berlin orchestra. Playing the violin had been his hobby and he was very talented. He lived in West Berlin, but played in the Metropol-Theater in East Berlin. After Berlin Wall was built, the orchestra changed its name to “Symphonisches Orchester Berlin”.

My mother, born in 1930, grew up on a ship. Her parents owned the ship that transported cargo such as coal, etc., along the Elbe and the Oder to Hamburg or other port cities. As my grandfather wasn’t a Nazi nor did he sympathized with them, in the mid-1930s he did not receive any more shipping cargo, which left the family in financial ruin. They had to sell the ship for next to nothing and to live in a one-room flat. The flat had to accommodate a family of four as my mother also had a brother who was born in 1928.

fter they lost their ship, my grandfather, who was 55 at that time, had to work as a night guard at a factory, which had to be very frustrating after having been a ship owner. He died shortly after the end of war. My uncle, my mother’s brother, started to study electrical engineering in Dresden and shortly after graduating became an engineer working for Telefunken and later AEG-Telefunken. My mother had an office job in that company and married my father in 1952. They split up shortly in 1956 and my grandmother and I moved to Berlin, where we lived in a small two-room flat with my mother.
Early on in my life, I was discovered to be very talented musically. As far as I remember, my first instrument was a chime on which I played all kinds of songs I heard at the age of three. Soon enough I started missing the half tones and I got a better chromatic instrument, so I could play in other harmonies or play songs that required the half tones. My mother often told me that she was impressed when I played Petit fleur after hearing it only once on the radio (which was the only audio equipment at that time).

My next instrument was a Hohner Melodica, which had keys like a keyboard. My father had a very good sounding piano at his home but he didn’t let me play it for the fear of disturbing his neighbours.
At school I began learning to play the English flute, to soon give it up as playing just one tone at a time was too boring for me. After that we bought an old piano and I began learning to play the piano. I was lucky to have a very good teacher, a 75 years old lady.
During that time, between 1962 and 1969 I joined a boy choir, the “Schöneberger Sängerknaben”. There I received a proper musical education, including music theory, and also became familiar with many kinds of music. Our choir was hired by the West-Berlin opera house, the “Deutsche Oper”, whenever they needed children voices. This way I got to sing in various operas, from Bizet, Puccini, Mussorgsky to Hans-Werner Henze, just to name a few. The choir demanded a lot of time because of two rehearsals a weak and live performances. We all learned a lot of discipline and also gained independence, as I had to go back home from the opera at 23:30 by train. We also travelled a lot with our choir. Another positive effect was that we got a little money for every performance. I had little but regular money come in every weak, which I saved for my other projects.

My other interest was electronics. When my other friends played Cowboy and Indians, I would go to the library and fetch some books explaining the inner workings of radio and radio control, and the principles of building model airplanes. I always had the desire to understand how things work. Eventually, I would build up radios and model airplanes. Radio controlled equipment was very expensive at that time and it took me several years to save enough money from my job as a choir boy, but I did it in the end.
My musical interest changed during my youth. When I was 6 years old, my favourite were German singers, like Freddy Quinn, the singing sailor and some similar stuff. Later I listened to the radio stations that played top international music charts. I bought a tape recorder to record the music by the likes of Bee Gees, Beach Boys, Beatles, etc…

I had a friend who was 6 years older than me. He influenced me with two things. First, when I listened to the music he played from a cassette player in his car, I was impressed by one track titled “Brandenburger”, which was Keith Emerson and his band’s “The Nice” version of Bach’s third Brandenburg Concerto. The most exciting thing was the sound of the HAMMOND organ. The second impressive thing was that he built up his own electronic organ, although he couldn’t play one single note. I decided to do the same. This organ was sold as a kit by a company called “Dr. Böhm”. I took several jobs to save up the money I needed to buy the kit. The end result was very disappointing. With the Hammond sound as my ideal, the organ sounded nowhere close to that and not like the church organ, either. Later I sold this organ to my father who liked it, and bought my first Hammond M-3. My first upright piano was replaced by an old Bechstein grand piano, which filled my small room.

When I was 16, there was a decision to make regarding my future. There was the possibility to study sound engineering to become a “Tonmeister”, which would be a good combination for my music and electronics skills. I would first study music and later electrical engineering. But the chance of getting a job as a “Tonmeister” in Berlin was very small, so I decided to treat music as my hobby and after finishing the high school started studying Electrical Engineering at the “TU Berlin”.
My favourite music around that time was mainly that which featured keyboards, especially the Hammond: Keith Emerson (Nice, ELP), Brian Auger, Jimmy Smith, Yes, Colosseum, and Friedrich Gulda, to be joined later by King Crimson, Miles Davis and others.
I didn’t really like orchestral music back then, but I enjoyed the combination of rock and classical music.
During my study at the TU Berlin a new technology developed: microcomputer technology. Long before personal computers became available, I built my own computer system. I was also fascinated with writing software and compiling own programs written in assembler.
As I always needed money for my hobbies, I had to work while studying. Hence, it took longer to finish my studies. During the last semesters I managed to build a house together with my girlfriend, with very little money. After I got my degree in 1983, I started my first job as a development engineer. At the end of the year I got married to my girlfriend. The work in the first company was not enough of a challenge to me. After nine months I quit and joined another company that claimed to have the highest quality methods and tools for software development. I started to work as a microprocessor software developer. I was involved in several projects, mostly communication software for local array networks (LAN). One of my ideas led to a patent, which I gave over to SIEMENS. After a short time I became a software project manager for various software projects.

My work for the company did not fully satisfy my hunger for knowledge. I started developing my own projects and building microcomputer software at home. With the money, I could fulfil some of my longtime wishes: I could afford a new Steinway B grand piano to replace the old Bechstein and buy a Hammond B-3. Buying a new grand piano was a process that took a lot of time. I tried out all kinds of brands, including Bechstein and Bösendorfer. But I found out that Steinway was the one that inspired me most. Still, finding the “best” one for me was not easy. Over a period of twelve months I played all Steinways available in Germany. In the end I chose the one that I reserved right at the beginning.
During this time my wife, who worked in the financial department, started her own business as a tax advisor. When her business grew, I wanted to help and to become a tax advisor. One requirement was to have a degree in economics. So I quit my job and started a second degree at the age of 36. Shortly after graduating our first daughter, Stephanie, was born. This event changed my personal career. As the second requirement was a three-year work experience in a tax company before you could take an exam, which is one of the hardest exams in Germany, we decided that I’d take care of the baby while my wife continued to work. Two and a half years later we had our second daughter, Julia. My plans had to change again. Because of my age and the overall economic situation in Berlin at that time, there was no chance for me to find a job in a company. In this situation I needed to think hard what to do next.
I looked at my Hammond B-3 which I couldn’t play as it was in Julia’s room. When I bought the instrument in 1990 for 11.000 Deutsche Marks, it was real fun to play at first. However, after some time I was no longer satisfied with the sound. I could play Keith Emerson stuff, but it didn’t sound the way I heard it on his records. The same was with Jimmy Smith stuff. I decided to move the B-3 to another room and started a new project: to find out why the sound had changed and to develop procedures for restoring the sound of these instruments. There turned out to be many people in various Internet user groups who were facing the same problem. I studied their opinions, but had the impression that they were taking a wrong approach. After working over a year in a more scientific way, I found out the real reasons for the sound ageing and was able to restore it. Hurriedly, I managed to join the MUSIKMESSE 2005 in Frankfurt, where I presented my restored B-3. The visitors’ reaction was very positive. My goal became to restore the sound of organs and to sell restored organ.

Restoring the sound of the Hammond organ raises one question. I had people come to me and ask: How can you prove that your restored Hammond sounds the same as original? You couldn’t have played this instruments in the 1960s (the Hammond used to be a very exclusive and expensive instrument at that time and was often sold by Steinway). My answer was very simple: Everyone can hear, how the Hammond sounded originally; just listen to the records that have preserved its sound before it’s aged. You just need to have a good quality HiFi equipment. When you play the same track with the same proficiency as the original instrumentalist did and employ the same register, it should sound the same as on the record. Then I would say that this is a stock-like sounding organ.
To present the sound of my restored B-3 to other people, I had to record it. I used 3 microphones in the same arrangement as for miking the Leslie and the same digital recording stuff. I had the organ in one room and my stereo equipment, a Burmester 911 amp and 877 preamp together with B&W 801 S2 speakers, in the other. The end result was disappointing; all the fine details produced by the B-3 and the Leslie were gone.
I first thought about changing the microphone placement. Then, while on my way to my electronic distributor, I had an idea of building my own amplifier based on a totally different design concept, considering that future recording process would be mostly digital. The idea was to minimize the amount of components used, as each additional component can cause unwanted side effects, which degrades the sound. My idea was to integrate the D/A converter into the amplifier in order to eliminate a preamplifier stage. As I was convinced that vacuum tubes are the only way to go for the best sound, I decided to use the 6C33 triodes. I developed a D/A converter that was capable of driving the 6C33 directly, without any coupling capacitor. The development took me over a year and many, many semiconductors sacrificed their lives on the way…
D/A converter output stage has to be optimized for best noise through proper deglitching techniques. To minimize distortion, I used other methods than negative feedback, as negative feedback is one of the worst things you can do to an amplifier. It gives the lowest measurable distortion but the worst sound at the same time.

When I was finally able to listen to this new amplifier, which I called D/AmP as it integrated the D/A converter into the amp as a preamplifier, the sound was terrific compared to my Burmester system. I used the same speaker, my B&W 801. I tried to patent this amplifier design, together with some other new concepts, only to be told that many aspects of my inventions had already been patented. However, I was granted a patent on one thing: my D/A converter with a native approximation output, which I call 4-switch D/A-converter. It turned out that even the concept of D/A converter integration into the amplifier as a kind of preamplifier had been known before. In 2000, Wadia presented an amplifier design called “Power DAC”, but its signal to noise ratio was too low and the project was cancelled.
All along, there was just one minor issue. I always had the feeling that vinyl records sound better than digital recordings. Yet my new D/AmP only had digital inputs. When I wanted to play analog stuff like LPs, I needed a phono preamplifier connected to an A/D converter, feeding a digital signal into my D/AmP. I used a high quality A/D converter and the Burmester 877 build-in phono stage. The resulting sound quality was disappointing. That system was no proof that vinyl records are better than digital, even though my analog front-end was of high quality: The SME 20 turntable equipped with the SME V arm and Ortofon Venice cartridge.

The reason could be the quality of the A/D converter or of the phono stage. As I used the best available integrated A/D converter, I tried to change the phono stage. From an audio dealer I fetched a 2000 Euro phono preamp that had very good reviews. It sounded even worse than the Burmester 877 phono stage. This is when I decided to design my own phono preamplifier. I studied all other designers’ concepts trying to figure out a way to avoid their design errors. My main objective was to eliminate any capacitors in the signal path (except those in the RIAA equalization network) and to use vacuum tubes in a fully balanced circuit topology. Hence, the whole phono preamp was DC-coupled. When my design was finished, the measured S/N-ratio was fantastic, especially for a tube based phono preamp. But when I plugged it to the Burmester 877 line input, the sound was not as good as the measurements showed. After some time I found out that while the Burmester 877 had balanced inputs, there was no differential stage in the input, which is necessary to make any sense of balanced signal processing. Instead, only one phase was processed and in the end converted back to balanced output. And to think that Burmester is so proud of its balanced signal processing…

In order to hear the benefits of my phono preamp, I designed my own preamplifier with true balanced signal processing. As I did not want to spend much money on such a preamp, I decided to develop a conventional analogue amplification system. The requirements were: tube-based circuit, zero negative feedback, DC-coupled, and no OTL.
The result of this was my “Holographic Music Reproduction System”, which basic prototype was ready shortly before I joined the Norddeutsche Hifi_Tage 2013 in February. At last I could hear the benefits of my Phono Pre and the sonic advantages of vinyl over digital. At the High End 2013 I could still only present my prototypes. I will hopefully present my fully featured system at the Munich High End 2014.
I have many ideas for the future: improving the sound quality with additional special signal processing (I know which and it’s no DSP) in order to have a product series above the E-series, downsizing the whole concept into a more budget-oriented direction, eventually selling my patented 4-switch-D/A as a separate unit, and at the very end maybe thinking over if there is any progress possible in the field of speakers (as it happened in the amplifier sector and which no one expected). Last but not least, developing an amplifier based on the D/AmP-concept to complete this project that started all other things…

Reading all this, it might look as if it were a straightforward development process, but it wasn’t. There were many situations when I thought I had enough and wanted to give up because of the problems I did not yet have solutions for. But being a triple Capricorn, I never really gave up on my project. What has been driving me forward was not the money, which I will (hopefully) make in return for many years of my efforts, but the desire to hear my favorite music in the best possible way. As you’ve learned, my life has been filled with many activities. Looking back, I would say that all I’ve done and what has happened in the past brought me to where I am now and proved useful for my recent project. As I do not have two left hands, I can do all kind of work myself, which sometimes comes useful and saves time as I am not dependent on other people. Even my interest in and adventure with the Hammond were necessary as they were the reason for starting my amplifier project. I did not mention that I’d never built any amplifiers before, except for an amplifier for my organ, when I was 14. If you had asked me, before I started my amplifier project, about my opinion on what’s the most important part in the audio system, whether the amp or the speakers, I would have pointed to the speakers. I’m glad I didn’t swap my B&W 801 for “better” speakers because paired with my amps their sound improved in the way I would have never expected. I took piano lessons until the age of 30 and never gave up playing the piano, which has helped me in my design and development work. Neither did I give up the music of my youth, and I still like to play it. As a matter of fact, I am now practicing a very difficult piano piece from ELP’s debut album, which is titled Lachesis and is part of the Three Fates suite. Although Youtube is a platform where many people upload their covers of Emerson stuff, this piece is very rare due to its technical difficulties. I may upload my version to show some of my piano skills. Anyway, it surely helps me relax from my work.


It’s not the kind of story you manage to read during a cigarette break, is it? Reading it for the first time, I felt like I were holding a movie script in my hand. Even though I already knew most of the facts. But Jürgen himself is a very interesting and colorful person. I spent a few days with him, listening, eating and drinking beer (in that particular order, to convey the “volume” of each) and a few things seem certain to me. He is a man who knows what he’s doing and has a clearly defined goal which he is determined to achieve. He is never in a hurry and if something requires more time he will devote time to it. Jürgen loves music and has a large collection of vinyl records, mostly original releases, some of which I have seen and heard for the first time. And last but not least, he designed and built an absolute top high-end amplifier system. Is it the best in the world? Uh, there’s no such thing. This system also has its own character. However, there are things about it I have never heard anywhere else.

The system is dynamic to the extreme, exhibiting near-live event dynamics (or something like that). You must surely remember my remarks concerning the dynamics of sound played back at home, on audio systems. It is merely an approximation, not even exact, of what takes place during a music concert. There is no physical possibility to transfer one experience onto another. The limiting factors are room dimensions, speaker size and amplifier power output. The latter seems to be largely minimized on Jürgen’s equipment. Vinyl records played on the KlangwellenManufaktur turntable with the Ortofon Anna cartridge had forward momentum and drive, or air and breath I only know from very few systems, rather with very large loudspeakers and more often from pro audio stage systems. Although dynamics is often associated with power, it actually depends on resolution and transient response (slew rate), and only then on output current. The latter is more important as a ‘peak’ or ‘impulse’ response rather than a constant current output. The Straussman system exhibits all these characteristics in one outstanding package. On top of that, it maintains great tonal balance. The Bowers speakers, Jürgen’s favorite, tend to dry up the midrange and prefer speed over fullness. So they sounded here. Yet there was so much sonic information and it was conveyed in such delicious manner that I easily waved it aside. The thing that helps us lose our natural reserve towards a new product from a new company is soundstage and space. I listened for a while to the Burmester system, in itself very capable, and it sounded as if it were playing mono records. After some auditory accommodation, something would click in my brain and I could hear soundstage again, but it took a while. Going back to reality, in other words to what the Straussman system proposed, took only about 1/10,000 second.


In his heart and on his lips, Jürgen is a Berliner through and through, a West Berliner at that. Since I took a peek at what living in that city might be like, I think I understand him and for a moment I felt like I was its resident. The lakes surrounding Jürgen’s villa, superb transportation system, fantastic food and great beer – they all make you want to live there (although I had to get used to the very light Pilsner they drink in Berlin; those drinking Bavarian ale or wheat beer are looked upon with gentle understanding that everyone has to do something stupid from time to time, and to taste something exotic). What’s also important is the proximity of Potsdam and the Sanssouci Palace, built by the King of Prussia much loved by the Berliners, Frederick the Great, whose Kapellmeister was Carl Philipp Emanuel Bach, Johann Sebastian Bach’s son. There is a well-known picture (featured on the Straussman website), in which Carl Emanuel playing the piano is accompanied by Frederick himself, playing the flute. And just to think he’s the same ruler who took an active part in the partitions of Poland that made it disappear from the map of Europe for more than 100 years.
Regardless of everything, next year I will go back there with my family because for a moment we all felt Berliners. And we loved it. WP