have already written this a few times: 1973 was a good year. Apart from my birth, some other important events took place then and became part of the history of audio. Among them, a few deserve our special attention: Rega Research, Naim Audio and Accuphase Laboratory were established, the Linn company presented its Linn Sondek LP12 turntable, Pink Floyd released The Dark Side of the Moon and the “Stereo” magazine started to be published in Germany. What we are interested in this time is the establishment of the Swiss company FM Acoustics in May (the month in which I also celebrate my birthday). The company was set up by an acoustics engineer, Mr. Manuel Huber, and has been a family company ever since, managed by its founder.

History

The company started as a consultancy and served as a research facility for small companies and laboratories focused on audio and acoustics. As we read in the company literature, Mr. Huber owns many patents in these fields. He has also developed some solutions that have not been patented, but are now being used by other companies, such as the shape of a loudspeaker horn of low distortion, a woofer with a coil cooled by forced air flow, etc.

The company’s first own commercial product was created as a result of a coincidence. While Mr. Huber was doing research on room acoustics, an amplifier used for taking measurements damaged expensive speakers a few times, generating constant voltage of 70 V on the output – no converter would handle that. To avoid any further surprises, Mr. Huber designed and made his own well-secured amplifier characterized by high output power, a high damping factor and efficient (enforced) cooling of output transformers. Only four such devices were constructed. Te looked like products from a recording studio (a standard in the 1970s).

And everything might have remained the same, if it was not for one of Mr. Huber’s friends – a musician who borrowed one of the amplifiers and refused to give it back, claiming that it was the best device he had ever heard in his entire life. This is how the first amplifier offered by FM Acoustics was created – the FM 800A model. It was soon followed by its smaller version – the FM 600A. Although these amps were only occasionally used at homes, both were strictly professional devices designed for recording and sound engineering studios. The first device designed specifically to be used at home was the FM 212 phono preamp.

Company policy

Although the FM Acoustics company is already 43 years old, we can find few of its product tests online. Compared to other brands, there are virtually none. There are also few of its devices sold on the secondary market. I saw them for the first time in the Japanese magazine “Stereo Sound”, next to rarities such as Goldmund, U-Bros and others. There are a few reasons why it is so and all of them result from the company policy.

One of them is the production scale. The devices are entirely made in Switzerland, usually using components available there. The transformers used are also wound at the company. Each piece is created at its own pace – there is no production quota to be met. Since the company is small, production is not increased, so the number of units ready for shipment is limited – you have to wait for them for quite a long time, just like for devices produced by Spectral or Phasemation.

Another reason why the company products are not present in the press is a conscious choice – Mr. Huber does not need publicity and “allows” others to conduct tests of his products rather than makes endeavor towards them. Finally, there is the issue of reliability – FM Acoustics products operate flawlessly for many years and their prices on the secondary market are not much lower than on the primary market. Besides, no one wants to resell them

FM 268C | FM 711 MkII

Acoustics

When we are “introduced” to the company devices, we instantly notice many elements that are unique to the brand or shared by it with just a few other companies. This is mainly stylistics – these are products rooted in the 1970s and taking pride in that fact. The champagne front panel (see Accuphase, Leben, Phasemation, Koda or older Luxman models), gold-plated knobs and characteristically shaped buttons are proudly presented here.

On the front panel of the preamplifier, next to the volume control and balance knobs, there are also five smaller knobs that are used to change the tone. The company name for the FM 268C is the Line Level Linealizer, which implies its major role – preparation of signal for the power amplifier, including tone correction. Let us not forget that Mr. Huber is a specialist in the field of room acoustics. A similar tool is also offered by McIntosh in some of its amplifiers.

However, the rear panel features something that I have never seen before. There is a row of potentiometers labeled as Acoustic Resonance Compensation. There are two sets – Comp 1 and Comp 2 – activated using separate buttons, comprising parametric potentiometers known from recording studios. In short – these are analogue narrowband filters with adjustable center frequency and intensity. Their function is to eliminate colorings resulting from room acoustics, especially when it comes to resonances at low frequencies. The range is from 20 to 100 Hz. They are set separately for the left and right channel.

The presence of these two elements makes the present FM 268C model different from the previous FM 268. Having corrected something in a previous device model, which does not happen too often, FM Acoustics adds the extension MkII to the device name. In this case, only the letter “C” was added. In the company materials, it is an abbreviation of a “correction system”. Thanks to this, we get a powerful tool – a line preamplifier with an in-built analogue room acoustic correction system which can also be used to correct the tone of recordings. Let us add that the FM 268C model was created in 2013 to celebrate the company’s 40th anniversary.

Cables

The company also has its own unique approach to cables, resulting both from opinions known from the professional market, as well as the company’s own experiences and technical requirements. Let us take power cables as an example – they are permanently attached to FM Acoustics devices and cannot be replaced. The intention is to ensure current flow undisturbed by connectors and plugs, and to make it unnecessary for us to buy them.

It is similar in the case of speaker cables. If we want to buy an FM Acoustics amplifier, we also have to purchase original Forcelines speaker cables. They have a very large section, are really heavy and made of copper wiring, and have banana plugs of an exceptionally large diameter at the end which enters the amplifier. The company says that its amplifiers have low output impedance, which is worth maintaining up to the loudspeaker clamps. All the devices have a symmetrical design and also offer such connectors only. It is best if we use the company own XLR interconnects. Unsymmetrical signals are detected by the preamp and power amp, and instantly converted into balanced signal.

Classics

Apart from that, these are classic audio devices. The FM 268C is a balanced A-class line preamplifier, without feedback. It offers six line inputs, an adjustable and unadjustable line output that is buffered and designed for recording or for a headphone amplifier. The device is equipped with a nice wooden remote control with volume control, the “Mute” mode and the activation of the tone change section.

The stereophonic FM 711 MkII power amplifier is much simpler to use. There are two knobs on its rear panel, which we use to adjust input sensitivity. When selecting it, we need to make sure that the volume control knob in the preamp can operate between 10 o’clock and 2 o’clock (clock position). Signal is supplied only through balanced connectors, which resembles solutions used in Nagra, BAT and Audio Research devices. It is a high-power amplifier, also at a peak – it delivers 260 W RMS up to 8 Ω, 500 W RMS up to 4 Ω and as any as 1000 W up to 2 Ω, and at a peak (respectively) 520/100/1600 W.

HARI STRUKELJ
The owner of Natural Sound

WOJCIECH PACUŁA: Hari, tell us about your company – Natural Sound. You are a distributor of FM Acoustics, aren’t you?
HARI STRUKELJ: Yes, we are. The company was set up in 2014 out of love for music and high-end audio equipment at my and my Polish partner’s initiative. After many years of listening to different, most demanding devices and speakers, we decided to show others the absolutely best products representing two different aspects of the top high-end approach to design: FM Acoustics, semiconductor devices and products based on Audio Tekne tubes.

How do these companies differ from other firms on the audio market?
We are deeply convinced that FM Acoustics and Audio Tekne devices are the last ones that demanding music lovers will purchase in their lives, as they will not need anything else afterwards. When we are done with experimenting and we truly begin to listen to music, this journey also ends. It is something we should strive to achieve in our wonderful hobby – forget about the system and get carried away by the infinite pleasure of music reproduction while sitting in a comfortable chair with a bottle of good wine. The exclusiveness of our products is connected with more than just the fact that we own them. The majority of important elements, such as music itself, are hidden from our eyes. This is what exclusivity is or at least should be.

Tell me a few words about the most important features of FM Acoustics devices.
Manuel Huber’s fantastic ideas have been incorporated into many elements useful for any music lover. For example, into the “Linearizer”, which can be used in any audio system and ensures immediate and considerable sound improvement. The FM 133 & FM 233 Harmonic Linearizers allow us to enhance not-so-well-made recordings precisely. Although the almost perfect recordings do not require using the device too much, good ones can become outstanding, medium-quality ones – pleasant, whereas some that we have not been able to listen to are now possible to listen to. The sound corrections that these devices make are very interesting and you must experiment to fully use their potential.

Another FM Acoustics revolutionary solution is connected with vinyl discs, i.e. the so-called “de-clicker” and “de-cracker” that we will find in the 223 phono preamp. This brilliant invention is for those who collect vinyl discs and those who have always complained about the crackling sound generated by their rare and very expensive recordings of superb music. Using two little buttons, in real time, you can reduce or even completely eliminate the crackling sound and cracks. The “Crackle Removal Circuit” which does the task for us operates, of course, in the analogue domain.

The third unique solution is the “Acoustic Resonance Compensation” circuit introduced in the 268C and 266C preamps. The ARC minimizes room modes and unwanted resonances. Modes occur when one or more resonances are generated between two parallel surfaces, and then get added to the musical signal, resulting in rumble and a weak bass definition. The ARC also helps us reduce other kinds of resonances, for example those coming from air conditioning systems. Similarly to the two previous ones, the ARC is an entirely analogue circuit.

As regards the Inspiration speakers and speaker cables, their greatest advantage is that the user can adjust system settings to any room. Thanks to this, we can always obtain the best sound everywhere we are.

Finally, there is a solution which is not accepted by many other high-end companies: the possibility to change the absolute phase. It is said that about 80% of recorded music is with reversed absolute phase. All FM Acoustics preamps are equipped with a switch that makes it possible to change it. If you do not change phase with incorrectly recorded music, you will not hear it in the right way.

What is your ultimate goal when it comes to audio devices?
The ultimate goal is to create an illusion of a real event with its weight, size, body and instrument colors heard against a black background.

Tell me a few words about the music you listen to, please.
After all these years, rock and progressive music have remained my favourite genres – e.g. Pink Floyd, Genesis, Jethro Tull and Uriah Heep, as well as my latest discoveries: East of Eden, Patto, Love and others. I also like jazz and classical music. Venice, The Royal Ballet and Clair de Lune are my three favourite classical music albums.

Line Level

When we choose an FM Acoustics system, we do not only get equipment for reproducing music, but also a serious tool which may help us adjust sound to the room which we will use and to our speakers. A change of sensitivity in the power amp makes it possible for the preamp’s potentiometer within a range in which its input and output impedance are optimal for the amplifying circuit. In my case, the knobs on the rear panel of the amplifier were set at 12 o’clock, the right one being turned on a bit more. The latter results from my loudspeaker setup – the left one is located closer to the side wall, whereas the right one, as a matter of fact, operates without it. In order to obtain similar sound intensity from both, you need to amplify the right channel signal a bit.

I also used the Linealizer and Acoustic Resonance Compensation. I write about the former in a separate section below. The ARC allowed me to reduce the main resonance which occurs in my room. However, I carried out the main listening sessions as if the FM 268C was a classic line preamplifier. Its operation in this mode is most important all the other possibilities make sense only if it is a top-class device in itself.

Recognizing the high quality of the device was not difficult at all. Instantly, from the very first track that I played, I could hear that the system without compensation is one of the most neutral systems that I have ever had at home. I will make this comparison already now, since it is going to be recalled: in this respect, only the Naim Statement system represented the same league. As regards shaping the tone, sorting out what is more and less important in sound, it is in the same group of audio devices as the tested FM Acoustics system.

The Swiss system delivers exceptionally clear sound. It seems that there is nothing between the source and speakers. I did not notice any compression or slowing down, not to mention the rounding of the attack. My Soulution 710 power amp reacts to signal in a similar way. However, when my system works with the Ayon Audio Spheris III preamp, it is a bit warmer, more “cultured” and polite than the tested FM Acoustics system.
It is because Mr. Huber’s system is very honest. It does not attempt to correct or improve anything. It is one of the best examples of how to pursue the ideal of a “straight wire with gain”. Of course, the device has its own character, mostly determined by how it “understands” the tone, but it is its intuitive nature that is secondary to clarity.

However, there are quite a lot of such transparent and accurate systems. I will go a bit further – you can buy some of them for a few thousand Polish zlotys. It is one of the views on how sound should be reproduced by an audio system, well-grounded in theory and engineering. However, as for me, there would be nothing more to write about, as music is, perhaps (this is my opinion on this matter, not any revealed truth), something more than that. In this way we approach the key feature of the Swiss system: it is characterized by exceptionally high resolution.
It means that an enormous amount of information that we get with it is ordered, coherent and full of meaning. It can be heard especially well at the treble that is as rich in decays, harmonics and chords as the treble in the highest-class SET-type tube amplifiers – or at least it is close to them. Among semiconductor devices, only the Naim Statement took a step further towards perfection.

So, the musical message is rich and tangible. I very rarely hear old recordings that require special care and attention sound so natural and spectacular. The voices of Ella Fitzgerald and Louis Armstrong were close to me, but they were not “plasticized” in this respect, like in tube systems before, produced by e.g. Einstein and Ayon. Also Miles Davis’s band (nonet) from the album The Complete Birth of the Cool sounded credible. The nature of these early recordings was bright and clear, but it was hiding under music. Even a much worse quality recording of a concert from the year 1948 had drive and rhythm.

Both the clarity and naturalness of the FM Acoustics system were demonstrated equally strongly in the case of recently recorded or remastered material, such as Jean-Michel Jarre’s Essential Recollection prepared for the Japanese market on a Blu-spec CD2, or Smolik’s and Kev Fox’s album. The treble was exceptionally sophisticated in its tone, while the midrange was meaty and dense. I was incredibly impressed by the dynamics. It seemed that the sound reached me instantly, without any medium in between. However, it was deep and full of content.

Now, however, something more could be heard – that the bass is shown with a bit of restraint. It does not lack anything and the control over loudspeakers is perfect, but that was sound close to (I need to make the comparison again) the Statement system. I do not want to be misunderstood: there is enough bass, but it is delivered quickly and shortly, so it seems that there is less of it. Tube systems, but also my reference system, sound lower and the emphasis is shifted towards the low midrange; the FM Acoustics system does not have a clear emphasis..

Linealizer

This is what the author of the article entitled The diet of a rational human being writes:

Diets are becoming contemporary religion. What do all religions do? They divide the world into what is saint and what is bad, dirty and harmful. The human being of the past, called “irrational” today, believed in many things that the authorities told him to believe in. Today, a new religion is talking to us in the language of science. We believe it, although the “diet facts” are constantly changing and if bring them all together, they appear contradictory to one another. However, we do not want to analyze all this. We want to believe that we have a religion which, just like any religion, brings answers to all our questions.

Paweł Droździak, Dieta człowieka racjonalnego (‘The diet of a rational human being’), “Wysokie Obcasy Extra”, January 2016, No. 1 (44), pp. 74-75

Does that ring the bell? Does it remind you of anything? In audio we also have as many “churches” as there are followers. This is because there is no single conventional interpretation of the Scripture, so we do not know for sure how a given recording should be played at home. So, there is a considerable margin which allows us to interpret things in our own way.
Having said that, I need to point out the very strong conviction that a signal path should be as short and simple as possible. This is why SET amplifiers produce such incredible sound – there are only a few passive elements in them, two or three simple lamps, a transformer – and that’s all. I have to say that I am a fellow believer.

However, I also have some heretical inclinations. My work at a recording studio and in the field of concert sound engineering taught me that it is usually necessary to find a compromise and that simple things are often too simple and therefore worse, which needs to be changed. That is why tone adjustment in the FM 268C was not a religious offense for me – I am talking about the religion of a “straight wire with gain”, the more that clarity did not become much worse when I compared sound without using this section and after activating it, with potentiometers set to zero. There is no point in deceiving ourselves – treble resolution became a bit worse, as well the foregrounds became less tangible. There are no miracles. However, the differences were not big – they were much smaller than what I had got used to with professional devices.

However, this became insignificant after I had adjusted the tone in a way that seemed best to me. After a short period of time during which I switched the Linealizer on and off with every recording, I left it turned on and listened to the rest of the recordings in this way. The corrections that I made were small, which shows the good quality of my system and listening room. We need to be aware that corrections higher than, let us say, 3 dB in any direction will show some serious mistake on our part. The changes that I made, fell within the range of +/- 1 dB, with one exception:

50 Hz/+1,5 dB | 200 Hz/-0,7 dB | 800 Hz/+ 0,7 dB | 3,2 kHz/– 0,5 dB | 12,8 kH/+1 dB

There is a rule in acoustics that “better is the enemy of good” and it is worth following in the case of such corrections.

With such a correction, the system delivered smoother sound that was more balanced and even more sophisticated. This was especially useful in the case of rock and electronic music albums. Without corrections everything was also ok, until I heard the recordings with compensation. The sound was a bit less energetic and the foreground was a bit further from us, although still close. However, individual elements beautifully “settled” – it is something that is done during the mastering process with the use of tone correction.

Summary

The Swiss system made a big and good impression on me. It could be used in a mastering studio of a good company as a reference amplifier. I am not talking about “studio” sound, it is not the right category, but JVC Victor studios and XRCDs, or about Jacek Gawłowski and his JG Master Lab (e.g. the Niemen’s album remaster). This means that at home it will give you source signal fidelity and variety which is usually sacrificed in the case of professional systems in the name of selectivity.

Room acoustics compensation is very useful and applying it is justified. The price we pay is slight deterioration of clarity and tangibility, but we get a message that is much richer when it comes to meaning. It is a case in which advantages outweigh disadvantages. Anyway, this is what people do in a recording studio. I have already mentioned Davis’s album and I did it on purpose. The version that I listen to was remastered with the help of Mark Levinson (yes, THE Levinson), using an analogue tone corrector called the Cello Audio Suite Palette. It sounds brilliant. We will obtain equally brilliant sound with the tested FM Acoustics system.

Both of the devices were manufactured in the Swiss FM Acoustics factory. They have champagne front walls made of brushed aluminum and their remaining walls are covered with gold-like paint that is highly resistant to scratching. It resembles paint used in studio and concert hall devices. The power amplifier additionally has something like a black “rim” around the golden front. Both devices stand on the company’s own plastic and elastomeric feet. In both cases, the power cables are inseparable and have high-class golden-plated Oyaide plugs at their ends. The devices are very well made and exceptionally robust.

FM 268C

The preamp is smaller than the power amp. There are a volume control and balance knobs on the front wall, both scaled in dB. At the side there are five gold-plated tone adjustment knobs with centre points at the frequencies of: 50/200/800/3200/12800 Hz and an adjustment range of +/- 6 dB. The adjustment is turned on using a separate button. Below we have two rows of the same buttons that we use to choose one out of six line inputs, the cassette player loop, the “Mono” mode, as well as change the absolute phase (signaled by a blue LED), and incrementally turn down signal by 20 dB. The last button is accompanied by another blue LED. There is a company logo illuminated in green, flashing in a window until all the sections stabilize.

At the back there are two rows of gold-plated Neutrik (Switzerland) connectors – six inputs, two adjustable outputs, one cassette player output and a multi-pin XLR with DC voltage for the company’s external FM 222/223 phono preamps. The housing is made of different types of materials. The top and bottom are made of thick steel plates, whereas the sides are thick aluminum slabs.

The device has a modular structure and our attention is especially attracted by black “cubes” that enclose individual active sections of the device. A similar strategy is used by a few other companies, e.g. the American Boulder. It is supposed to make it harder for competitors to copy the solutions used, as well as to keep similar temperature for all the active elements.
There are separate boards for the amplifying section, with a malachite motorized Alps (Japan) damper; for the tone adjustment section where we also have Alps potentiometers (black this time); for the “compensator” section with micro potentiometers, as well as for the input section. The compensator circuit uses potentiometers with conductive plastic specially selected for this purpose .

The power supply is located on the main board. It consists of a large toroidal transformer, Nichicon capacitors (Japan) and active elements that are attached to the side panel. Signal is amplified in low-noise transistors, selected manually with regards to the curve and distortion. The circuit does not have feedback.

The remote control is placed in a wooden housing. Using gold-plated buttons, we can change volume, activate the “Mute” mode or change the absolute phase of the device. If we look inside, at the board with input connectors, we will see a small switch next to each XLR connector – apparently, these switches are used to pre- set the absolute phase.

FM 711 MkII

The original FM 711 model was created to be sold exclusively on the Japanese market, as a result of an agreement with a local company distributor. In 2008 the agreement expired and FM Acoustics prepared an updated international version of the device with the Mk II extension in the name. Other company devices had led to the creation of the tested model (e.g. the FM 1811, FM 115 and FM 411-MKII). Among the improvements, there is a considerably larger power supply unit in which double bridge rectifiers of a high switching speed have been used.

The power amp is large and quite heavy. There is the characteristic, illuminated company logo on the front panel. After switching on the power supply, the series and company name are also displayed under the oblong black plate. At the back we have speaker connectors in the form of openings in the housing – something also used in Naim devices, for example. Here the openings have a large diameter and standard “banana plugs” will not fit in them. The connectors, called the Forceplug 200, are manufactured by FM Acoustics. Above, there are gold-plated input Neutrik XLR connectors and knobs that we use to set the input sensitivity of the amp. Instead of carbon potentiometers, the company has again used potentiometers with conductive plastic. They are much more resistant to ageing and abrasion. The housing is made entirely out of thick steel plates.

When we remove the upper plate, we discover that inside the main housing there is one more housing, shielding the whole power supply unit. It includes eight large Nichicon capacitors that filter ripple voltage, situated right next to output transistors, but the transformers are hidden beneath. The input section consists of small HR modules. Thanks to them, the device is characterized by excellent efficiency in eliminating CMRR distortion (i.e. noise, interference, etc.) at the level of - 100 dB. This is an A-class circuit which automatically detects whether the input signal is balanced or not, and adjusts to it. Unsymmetrical signal is made symmetrical right at the input.

The control section uses Motorola transistors of a very rare TO-5 type, with a round metal housing. These are NOS elements that have not been produced for a long time, known from the 1980s – complementary bipolar pairs 2N5416+2N3440. They are cooled using compatible radiators. Transistors that look like Toshiba elements operate in the power amp. However, their original inscriptions have been removed and replaced with the inscription “FM 17420”, which was done at the FM Acoustics factory. All the transistors are manually selected and paired. The current section operates in what the company calls an “enhanced Class”, which should be read as “A class with alternating bias.”

Technical specifications (according to the manufacturer)

Minimum power output:
520 W peak/8 Ω
1000 W peak/4 Ω
1600 W peak/2 Ω
260 W RMS/8 Ω
500 W RMS/4 Ω
800 W RMS/2 Ω
 
Maximum output voltage: 140 V pp.
Maximum output current > 35 A (continuous)
Distortion: 0.005% THD
Bandwidth: 1 Hz – 60 kHz
Risetime at full power: 3 μs
Hum and noise: -110 dB
Input sensitivity: 1.6 V RMS
Input impedance: 40 kΩ