In the most impressive audio set up I have ever had the opportunity to listen to, two 1000-watt power amplifiers were taking care of the amplification. However, the most expensive and even several times more powerful power amps that I came to host in my listening room were rather a disappointment. And now MSB's 1000-watt bolides have been bustling there for weeks. How much power does one actually need?

My colleagues Saile and Bussler may consider ten, in exceptional cases perhaps even 20 watts to be completely sufficient and point out that loudspeakers with a correspondingly high efficiency can also ensure absolutely satisfactory volume levels with this wattage. If you want to concentrate on this matter in depth and are not put off by a text in German, I recommend Jürgen Saile's very informative feature article on the subject. I can't and won't contradict the physical facts presented there, but I do disagree with the view that high efficiency transducers simply don't know how to put these loads of power into practice, for the loudspeaker system of the aforementioned audio chain, the Acapella Audio Arts Sphäron Excalibur, driven by two 1000-watt mono blocks, excels with an efficiency of over 100 decibels per watt and metre: Instantly everybody is set to enjoy transients like in a live music performance. The Excalibur does not seem to have any dynamic limitation - at least none that is below the pain threshold of the average human ear. However, I certainly don't want to propagate the mere abundance of power here. It would be too good to be true if wattage was going to be the only criterion to mark the quality of a power amplifier. Then we all could relax and simply go for the t.amp E-1200 offered by the German music trader Thomann, a Class-H stereo amplifier at a price of 229 Euros, which still delivers 1200 watts per channel into four ohms, and waft away into ultimate audiophile delights. Unfortunately, this happens not to be the case.

When reviewing the Goebel Epoque Fine, the predecessor of my current speakers, more than eight years ago, real watt monsters had to replace the fine Brinkmann mono amps, as they had fallen victim to the impedance drop of the Epoque Fine at that time. When it comes to sound, however, the two power plants could not hold a candle to the Brinkmann monos, which were certainly going through stressy moments even before they passed from this life. It is commonly much more difficult to develop a power amplifier with, say, 1000 watts than one that sounds just as good with "only" 100 or 200 watts. That's why the designers of the MSB M500 amps should at the outset deserve the highest praise if their monos were going to perform as light-footed and nimble on the now finally amplifier-friendly Epoque Aeon Fine as Einstein's The Poweramp with its mere 140 watts per channel into four ohms. But more about the sonic outcome later.

As one might expect from experience with one or the other MSB component - and also by looking at the price tag - these monos are perfectly finished. The fact that their shape - a rectangle with strongly rounded corners - echoes that of the plinth of the Goebel transducers is, of course, pure coincidence, but it contributes to the circumstance that the MSBs - despite their impressive physique - perfectly integrate in my spatially quite limited listening room merely because of their looks. Furthermore, MSB lets also their monos follow the company's proven plain and functional design path. There are neither edgy cooling fins nor handles - although these would be mostly welcome when transporting these heavyweights - nor any other swaggering visual digression - very well done indeed. Speaking of heatsinks: each of them is milled from a block of billet aluminum weighing over 23 kilograms in a process that takes about eight hours. What remains are two structures weighing about eight kilograms each, which with their combined surface area of 6.45 square metres ensure sufficient heat dissipation. As this effort is made, the dimensions of the cooling fins can also be varied to optimise the resonance behaviour. The M500 mono blocks are devised as a modular concept, so that the S500 stereo power amplifier can also be assembled from this module system. MSB entitles the huge toroidal transformer, the capacitor bank with its 1,000,000 microfarads or, shorter, one farad, the output stages, as well as the input stage with its switchable input impedance as "cores". After completion, these cores are subjected to rigorous quality tests and then stocked so that orders can be responded to spontaneously.

But let's throw a brief look back at the switchable input impedance: Of course, MSB makes a point of ensuring that the power amplifiers harmonise particularly well with the D/A converters that established the company's excellent reputation. As described in the report on the Reference DAC, the outputs of the one, two or four ladder DAC modules, depending on the model, are followed neither by a current/voltage converter nor by a buffer circuit. The result is on the one hand a very short and puristic signal path, but on the other hand a not particularly high output voltage correlating with a quite powerful output current instead. This is not worth considering when using a preamplifier with a high-impedance input. However, in order to drive a power amplifier directly and perhaps also via longer signal cables, it might be useful to rely on current matching instead of voltage matching between the converter and the downstream power amplifier. This also has the advantage of minimising the sonic influence of the connecting cables. On the M500, MSB therefore provides an impedance of 75 ohms for the Select and Reference DACs, 300 ohms for the other proprietary converters and 1.2 kilohms for preamps from other manufacturers. But even this value might not be the ideal match for i.e. tube preamps with a quite high output impedance. With Einstein's The Preamp, however, I chose 300 ohms. Its developer, Rolf Weiler, is not averse to the principle of current matching and has therefore treated the preamp to a very current-potent output stage. The lucky owners of an MSB converter who prefer a short signal path and want to get by without an additional preamplifier cannot have better game partners for their noble DACs - also from a technical point of view - than MSB power amplifiers with matched input impedance. In addition, the M500s also feature a three-step switch for selecting the gain factor. This ensures that the passive volume control of the MSB DACs can always be operated in the optimal range, even on speakers with very different efficiencies.

Naturally, I started enjoying the MSB gear first as a full set for a few days, before I took a closer look at the Reference DAC on its own and listened to its various input options in familiar surroundings - i.e. in combination with Einstein's The Poweramp and sometimes with, sometimes without The Preamp. I had speculated that the Reference DAC could remain in my listening room until I gained sufficient experience with the M500s, but, unfortunately, this went out not to be the case. Jürgen Sachweh, head of Hifi2Die4 and thus MSB distributor for Germany, required the converter back for a demonstration. So I quickly compared it once more to the M500s connected to my digital chain, i.e. the Aries G2.1, the M-Scaler, the DAVE including batteries, and linear power supplies alternatively, in conjunction with the Einstein preamplifier indispensable in my set-up, to get an idea of how much enjoyment I would have to forego if the M500s were forced to do without the Reference DAC. Admittedly, the Auralic-Chord-Einstein combo spoils with a touch of euphony - or more trivially: a minimal loudness effect. The slight emphasis on the low and high frequencies can be quite appealing in some recordings, but unfortunately also adds a touch of roughness to the latter. The MSB, on the other hand, intrigues with smooth and always pleasant highs, proves to be a prime example of neutrality and tonal balance and shines with an even wider and deeper soundstage. Thus, it remains strictly committed to the ideal of high fidelity, but at the same time offers the highest grade of musical enjoyment. Blessed are those who can afford to keep this digital epitome of dreams in their listening room after an extensive testing.

But let's now move to the M500s. Regardless of whether the Reference DAC or my digital system in unity with Einstein's preamplifier supplied the signal, every time I switched from the Poweramp to the Californian monos and back - and there have been quite a few of these interplays in the last three months, even though there was no direct comparison yet - the impression that the MSBs help the playback to have a more sonorous and solid low-frequency foundation became increasingly obvious. The Poweramp delivers a touch more energy in the upper frequency ranges, which sometimes makes it appear slightly more nervous. Nevertheless, the M500s seem to perform a shade quicker. But before I compare the power amps more intensively, I'll first take care of the operating conditions of the monos: Since they draw their power via an IEC-19 socket, but the six-metre-long mains cables required for connection to the Audioquest Niagara power conditioner with its sound-enhancing Power Correction circuitry being fitted with IEC-16 plugs, the only way out was to do without the Niagara's capabilities or to use the existing cables with an Isotek IEC C13 to IEC C20 adapter. I finally opted for the latter.

And that had certainly a positive effect on the M500s. In my listening room, I use to have manufacturers, distributors and colleagues dropping by from time to time, although in these times much less frequently than usual. Their assessments are particularly interesting for me when they don't focus on the component that occupies me the most at the moment. Last year, for example, two developers from a very renowned loudspeaker manufacturer came by to get an impression of the quality of my audio system and were particularly impressed by its coarse and fine dynamic capabilities. Just because it was not an issue which power amplifiers were in charge of the efficient amplification, I took their statement as a huge compliment for the 1000-watt MSB powerhouses, which had their good share in the convincing performance. For me, it had been clear for a long time that the M500s do not in the least correspond to the audiophile prejudice against high-wattage power amplifiers. No, despite all their forces, the MSBs cannot only run for power, but sprint likely to break world records!

Recently, Oliver Goebel popped again in because he had not yet heard the changes - or improvements respectively - made by the Ferrum power supply for the M-Scaler and the linear power supply for the DAVE. Moreover, he was not averse in becoming familiar with the M500's sonic potential. We also took the opportunity to experiment a little with the coupling of the MSBs to the floor, which hadn't been so easy for me because of their weight. By default, the M500s come with very soft feet that decouple the monos from the floor. In their place, we installed the Ansuz Acoustic Darkz T2 Supreme under the MSBs. Where, if not here, would the use of these titanium feet, which are anything but affordable and have undergone a special surface treatment at the Technological Institute in Aarhus, be reasonably priced in relation to the devices resting on them? Acoustically, too, the Darkz feet appear to be an excellent match for the M500s: A touch of energy, however, gets lost in the lowest lows, but on the other hand, the frequency range from bass to midrange has more strength and sounds even rounder and more coherent. And also the transparency and the tonal colours get enhanced thanks to the Darkz. For example, I have never heard the hi-hat at the beginning of Abdullah Ibrahim's "Calypso Minor", one of Oliver Goebel's favourite test tracks by the way, as colourful as it sounded now. The pressure of the double bass instantly captivates you, and the reverb surrounding the hard-stroken strings of the grand piano now stands out with more clarity. So we ended up in avoiding any further change in the placement of the MSBs. We reached to be perfectly happy.

Just for fun, we then listened to one of my favourite new files: Bassroom, the solo album by Austrian bassist Nenad Vasilic, downloadable from Qobuz at a sampling rate of 96 kilohertz. Besides Vasilic's virtuoso playing, it fascinates with different virtual spaces, a track with prepared strings, the change from double to electric bass and from con-arco to pizzicato technique, as well as the relatively scarse use of electronics: Not least thanks to the MSBs this is sonically a pure delight! Even when I reconnected The Poweramp instead of the M500s to the system, I still was in an excellent mood, probably because I assumed that the aforementioned differences between the monos and the stereo power amp happened to be quite marginal. How mistaken one can be: As is so often the case, the step back to the less perfect component is far more noticeable than the one from the very good to better ones. The same is true here: It suddenly became obvious that the MSBs had an even better grip on the Goebel drivers by nevertheless letting them produce more thrust at the same time. Spaces got a bit bigger, the tonal colours a bit more radiant and the differentiation a bit more accurate. Despite - or against all prejudices: because of? - their immense power the MSBs not only reach the very high sonic level of Einstein's The Poweramp - oh no, they clearly outperform it!

Before Helmut Baumgartner and I start moving the M500s from my listening room to the photo studio, we briefly listen to the fourth movement of the Symphonie Fantastique with the Utah Symphony conducted by Varujan Kojian. I've probably never heard this Reference Recording copy so open and airy: Already during the first few seconds, the enormous spatial depth is impressive, despite the volume is at a very low level here, while the explosive dynamics add highlights to the exceptionally transparent sonic image. The kettledrums towards the end of the piece evolve exceptionally fast, controlled and yet extremely powerful. No other amplifier that I came across so far has managed to master this very demanding piece so sovereignly. Helmut Baumgartner found even more prosaic words for it: "I've never heard such musical power amplifiers with so much power." This is a conclusion I fully share.