In response to the seeming contradiction of on the one hand purveying massive power from his A5.5 and above amplifiers whilst at the same time re-releasing the 30 watt A1 Anthony Michaelson has sent the following missive out to the world ...

Dear Fellow Music Lover,

Many customers ask me about the design aims of my products. They are particularly puzzled by how Musical Fidelity can strongly promote the merits of high powered amplifiers such as the 550K or 750K whilst on the other hand producing low powered amplifiers such as the A1. I’d like to try and explain my ideas.

First off, it is not uncommon for companies to produce a wide range of products with vastly different performance potential and technologies. Look at Mercedes. At the bottom of their range they make the Smart car and at the top they have their AMG black range. Similarly with BMW. At the bottom they have a Mini City diesel and at the top their M Series. Look at cameras. Canon, Nikon or Fuji all produce very small budget “happy snappers” at the same time as producing super quality top end products.

There is no philosophical problem with that. People accept that the design ideals of the most expensive products filter down to their entry level range.

Musical Fidelity follows exactly that idea. The philosophy behind all our product designs is the same. Our aim is to give maximum value for money and superb performance at any particular price-point.

Accuracy and realism.

I strongly believe that with an ordinary high quality loudspeaker of about 87dB sensitivity you’ll need about 500 watts to avoid any clipping or limitation. I cannot stress strongly enough that this assumes that you are using the system at a healthy, quite loud, listening level. If you listen quietly or are in a small room or sit close to the loudspeakers, the high power figure is irrelevant. My point is that if you want accuracy and realism the amplifier should never clip or limit.

How can you judge a loudspeaker, CD player, a particular disc or any other component if the amplifier is clipping or limiting? I don’t see how this can be possible.

Keith Howard’s research.

Keith Howard is an experienced technical journalist. His research has confirmed that 500 watts power is a good level for a properly neutral system. He also suggests that if you really want no clipping, that you would need even more power. His position certainly appears to agree with ours but there is more to his research. After finding out how much power he thought the system should have, he then set out to find out how much clipping would be subjectively acceptable without much apparent loss of neutrality.

After a lengthy experiment, Keith found that about 3dB of clipping did not cause much upset. This equates to 250 watts.

To summarise the above: if you want to be sure of almost complete accuracy and neutrality you need an amplifier of 500 wpc (or more) but 250 wpc will be acceptable for most people most of the time. A little inaccuracy never did anybody any harm.

Accuracy and impressionism.

A properly designed high powered amplifier such as the 550K or 750K will be highly accurate and faithful to the original recording. It won’t clip, limit or distort driving almost any loudspeaker to the full dynamic range of the recording. This is what I call accurate.

On the other hand as you come down in power the likelihood of the amplifier clipping increases so that, in my opinion, there is a direct correlation between reducing power and decrease in musical accuracy.

Once you are below 100 watts clipping (with my previous points taken into account) is a regular feature. It follows that the dynamic reproduction is no longer neutral, accurate or low distortion. Once you’ve reached this area subjectivity becomes far more relevant. Each amplifier has a unique clipping/limiting characteristic when paired with a particular loudspeaker. Nobody can pretend that the reproduction is accurate, all it has to be is convincing.

This is the true background to the A1.

Okay let’s get to the nitty gritty of the A1.

Some people find it almost impossible to grasp that I can put forward the above case for high power but still produce an amplifier like the A1 which has only 30 wpc. It’s like this. Almost as soon as an amplifier drops below 250 wpc, clipping and limiting will become more and more of a feature of the reproduction. In my book that means as the power reduces the inaccuracies increase.

Once you’re down to below 100 watts amplifiers will be clipping regularly. At this point reproduction is inaccurate. Now the amplifier design is rather like an impressionist picture. It cannot be a photographically accurate representation of the recording but somehow has to create the impression of the musical performance. At this level the limitations of the amplifier have to be accepted as a constant and the design has to be created in order to give the most convincing illusion of musical accuracy.

Now to the A1. Yes it doesn’t have much power and yes it’s clipping regularly (but not much more than any other amplifier below 70 or 100 watts) but we have accepted its power limitations and have decided to engineer it to produce a convincing, beautiful, musical experience.

When I listen to the A1, I am completely blown away by it. It has an apparently sweet, subtle, delicate sound which seems to make something of a nonsense of my high powered ideals.

However, as soon as a you switch to an amplifier which has enough power not to be clipping, it is immediately obvious what you have been missing. The point is that whilst listening to the A1, its ability to project and create musical illusion is so strong that I don’t object to its power limitations. In my world, that’s job done.

Let’s get realistic and accurate.

In my opinion the beginning of any properly realistic accurate amplifier is enough power so that it very rarely clips. That power rating is about 250 wpc. Enter the A5.5 and A1008. Both these amplifiers are engineered to produce very accurate high quality sound. They have ample power, very low distortion and produce a sweet sound that appears in contradiction to their high power rating. The thing about high power rating is that if the amplifier is well engineered it won’t sound powerful. Actually quite the reverse a properly designed amplifier will almost never clip or distort. To inexperienced ears it will sound unexciting and undynamic. Actually what these inexperienced listeners can identify is the harmonic enrichment created by clipping. It’s ironic isn’t it? Only when an amplifier is clipping or limiting can they pick up the sound and confuse distortions and non linearities for what they call rhythm incisiveness and richness.

Over the years I have had endless frustrating run-ins with reviewers and hi-fi salesmen about the accuracy of what they’re hearing. When I have taken them a proper, high powered amplifier to use, their immediate reaction was that it was “dull” or “undynamic”. What they were hearing was completely faithful and accurate but what they wanted (or perhaps expected) was the usual clipping and limitation. Very, very, very frustrating.

How to create a super performance system.

If, like me, your quest in hi-fi is musical accuracy and realism then the only way is to have 500+ wpc so that it’s almost impossible to clip or limit the amplifier. Then your loudspeakers can sing the music.

To make a really superb electronic chain, I strongly recommend our A1 CD as the primary signal source. It uses the Philips CD Pro2 and has great technical performance. It has a fabulous, neutral, clean sound. If money is no object the A1008 CD Pro is a bit better.

After the A1 CD Pro should come our A1 fully balanced preamp. This is a super performing, genuinely fully-balanced preamp. Most so-called balanced products are nothing of the sort. What they have is a balanced input and balanced output but the electronics between is single ended. The A1 FBP is fully balanced from beginning to end. Even though it’s in modest casework the circuitry inside is, pretty well, as good as you can get. Not surprisingly so is the sound.

Couple the A1 FBP to a 550K (used in power amp mode) and you have a really extraordinary amplification system. This system will drive any loudspeaker to any reasonable level you might require. It’s really great. I know it’s not the most expensive, or the biggest, or the flashiest but my ears tell me that I’ve hardly ever heard a better electronic system.

If money is very tight (and it’s always tight for me!) but you still want to get an ultimate system and don’t mind sacrificing facilities, I recommend that you use try our X-CanV8 as the preamp to drive either the 550K or 750K. I know it sounds like an extraordinary idea but stay with me for a minute on this one. The X-CanV8 has the same gain as any of our preamps. It has a single ended Class A tube front end with an ultra low output impedance (below 1 Ohm). If you don’t need loads of inputs, a big flashy box or a high price tag then the X-CanV8 used as a preamp (you can easily get an adapter which plugs in the headphone socket) makes a fantastic preamp at a very competitive price.

If you want even more, then our fully balanced 750K is a revelation. For many years I’ve had a kW750 at home because, in my opinion, I’ve never heard a better amplifier. When I substitute the 750Ks I really can’t decide between the two of them. The 750K’s stereo placement, imaging and (I know this is a ludicrous word but here goes) ability to make the music breathe is really arresting. On the other hand the kW750 power amp seems to exercise an iron grip on the loudspeaker and maybe (or then again maybe not) has a slightly more extended bottom end. The point of the matter is that either of these amplifiers is, in my opinion, as good as I’ve ever heard anywhere.

Musical Fidelity’s aims.

I am proud of Musical Fidelity’s aim of making the best quality performance product at a competitive. Many hi-fi enthusiasts simply cannot understand that equipment can be modestly priced and yet offer state-of-the-art performance. I don’t think they would ever want to hear what I’ve got to say. If, like me, your religion is music and all you want to do is to get the best possible reproduction then give our stuff a good hard listen and try to forget its modest price. You may well end up feeling the way I do about it.

Yours faithfully,

Antony Michaelson