MSB Platinum M200 review

Who the heck is MSB? And how come they've come up with the Platinum M200, such a strange, yet wonderful amplifier?

The company based in Aptos, California, has been around since 1986. Although it does make and sell a certain amount of high-end hi-fi equipment, it has never been particularly pro-active in marketing.

Furthermore, a good part of its work has involved working as consultants on specific engineering projects for other brands – work that naturally tends not find its way onto the formal CV.

Most of MSB's activities are concerned with various digital audio techniques and its website claims a whole succession of 'firsts' in the gradual development of different digital formats and techniques over the years.

The current product portfolio includes a considerable and indeed somewhat confusing collection of DACs, ADCs, upgrade packages and suchlike, nearly all related to digital audio. The iLink looks particularly interesting, for its potential ability to turn an iPod into a high quality music server.

This M200 Platinum monoblock power amplifier is one of relatively few analogue components in the catalogue and MSB describes it as, 'built out of desperation'. The blurb continues: 'Designing the Platinum DACs, we found there was not an amplifier available that could let us hear everything that our DAC is capable of... We needed a Reference amplifier and that is what we built!'

That seems as good a reason as any for embarking on a project to design and build an amplifier. The questions that need to be answered are why a digital audio specialist thinks it can create a superior analogue amplifier and what original thinking it can bring to the party. The answers are seen clearly enough in the amplifier itself.

The M200 Platinum is unusual in a number of respects, some more obvious than others. To start with there's the cylindrical shape. Perfectly logical in its way, but ill-suited to mounting on the usual equipment rack. it's not unique in this respect; ironically, the last standalone power amplifier we reviewed in this very journal was Musical Fidelity's similarly cylindrical 550K Supercharger amplifier.

• Read TechRadar's Musical Fidelity 550K Supercharger review

However, other than the shape and the need to place them on the floor, these two amplifiers are very different. Whereas the Musical fidelity cost £3,000 per pair and weighed 12kg each, this MSB device is an altogether more substantial device, weighing some 40kg each and costing £13,656 per pair (recently and substantially increased due to the drop in the international value of sterling).

Furthermore, it delivers 200 plus watts into eight ohms and can double this into lower impedance loads. The M200 Platinum is, therefore, a very serious amplifier indeed.

The shape might be a little unconventional, but the build and the price put it firmly into the 'highend' category of amplification – nowhere near as costly as some of America's more pretentious offerings, but at least as costly as any UK solid-state devices.

The finish is unconventional, too, though undeniably attractive in its own rather individual way, dominated by the considerable area of metallic-anodised blue heatsinking that surrounds the gilded amplifier section. And because it's probably going to sit on the floor, a circular gilt cradle is supplied, with tri-cone coupling to the floor and some foam damping for the heatsinks.

In order to keep all the signal paths short, the amplifier proper is deliberately contained within a tight space in the middle of the column, above the very generous power supply components (dual 600-watt transformers plus 220,000uf capacitance). A section within the cooling fins is cut away to accommodate the inputs (balanced XLR or single-ended phono plus iec mains) and outputs (one pair of high quality 4mm socket/binders).

A switch is used to select between the inputs, the balanced one having a +22dB/+28dB gain option. The actual on/off selection is done by a removable toggle switch in the top surface next to an indicator LED – a curious approach that does, at least, prevent the amplifiers being accidentally switched off – though to stop it getting hot, the mains must be physically disconnected!

The amplifier topology is fully balanced throughout and uses accurate current-mirror circuitry designed by MSB. That, in turn, allowed the amplifier to be designed without any feedback at all (global or local), to the considerable benefit of the phase response. Bi-polar transistors are also used throughout.

The heatsinks might dominate the appearance but they need to. The one practical problem with this amplifier is that it runs very hot. Not because it's a traditional class A design, which it is not, but rather because the input stage operates in class A and is actually responsible for half the generated heat.

Each of these monoblocks generates around 250 watts of waste heat, even when it's in standby. And even when it's merely left plugged into the mains!

As a laboratory tool for the prime purpose of developing MSB's DACs, such a consideration matters little; for the hi-fi person whose amps are in regular use day in and out, it's a more serious issue, especially for those without air conditioning and/or concerned about energy consumption.

We asked MSB whether it would be possible to create an amplifier without the practical handicap of so much wasted heat and it seems that some such options are theoretically available. Some power could be saved by halving that used by the input stage, though this would limit the maximum power available into two ohms to 400 watts.

More could be saved by reducing the output stage bias. Indeed, a lower bias setting is normally used, though our samples were shipped with the high bias setting, giving a marginal improvement in sound quality.

Clearly a rather more user-friendly variation on the M200 theme is at least feasible. Since no balanced-output preamp was available, the M200s were only tried in single ended mode, fed on this occasion from Naim NAC552 and XTC Pre-1 preamps.

Sound quality

It's quite difficult to discuss the sound of an amplifier that is, quite simply, the best that we've heard to date. The purpose of a power amplifier is to amplify the source and drive the speakers and the ideal example should add no character or 'sonic signature' of its own.

That does indeed seem to be the case with this M200 Platinum. One could describe it as sounding absolutely wonderful, but that, perhaps, is the same as saying it doesn't sound at all. it simply amplifies the signal, across a wide bandwidth and dynamic range, accurately, precisely and without any apparent discernible character of its own.

Everyone's familiar with the alternative stereotype characters of valve/thermionic and transistor/solid-state amplification: the former with its delicious midrange, alongside some limitations towards the frequency extremes; the latter with its superior bandwidth and power delivery. The M200 Platinum somehow seems to supply most of the better characteristics of both approaches.

It might not have quite the romantic midband liquidity of the very best valve designs, but there's no sign of the thickening or congestion that tends to characterise solid-state devices. There's certainly no particular sweetness here, real or artificial, but neither is there any harshness.

Rather the sound delivered by the M200 seems fundamentally neutral and uncannily consistent, irrespective of the type of music played or its complexity. When asked to rock hard, they rocked hard; asked to deliver the subtle textures of orchestral strings, they handled this beautifully too. This was wholly apparent using our current reference speakers, a pair of essentially neutral PMC iB2is, which are notable for their wide bandwidth and dynamic range.

In fact, results were so impressive we took the unusual step of bringing in Rehdeko 175s. Although they're far from neutral, they're still the 'fastest' speakers we've heard and possibly the most critical of amplification.

A little to our surprise, their partnership with the M200s was excellent, which only served to confirm our suspicions that this is one of the very finest power amplifiers on the planet. The practical considerations of excessive heat output, plus some mechanical hum remain something of a deterrent, but are, at least, potentially soluble.

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