Audio Research 300.2, Classé CA-M400, McIntosh MC 501 Power Amplifiers

Why are amplifiers so important?

But, which areas?

The first thing I looked at was the way the amplifiers treated the frequency range. This seemed natural, because many descriptions of how equipment sounds attend to the handling of different frequencies—bright, warm, light, etc. I’d have to say that I didn’t find big differences in this arena. But, since we’re talking about tweaking at this stage, I would also say that the McIntosh and Musical Fidelity were slightly warmer sounding than the ARC, for example, but not much. The Classé had a different balance as well, with ever so slightly less treble energy than either the McIntosh or the Musical Fidelity. Still, across the spectrum the emphasis on different instruments was very similar from amp to amp. Perhaps this is why, in a quick A/B test, many people don’t sense that amplifiers sound very different.

Much listening did highlight that these four amplifiers do sound different when you think about how extended they seem to be at the frequency extremes. I would say, for example, that the Musical Fidelity and the McIntosh have a more rounded sound, and the Audio Research sounds more extended. But before you rush to the conclusion that one of these approaches is right, and the other wrong, let me say that by “rounded” I mean that I could imagine the frequency response being slightly “n”-shaped, and by extended I mean that I could imagine the frequency response being slightly “u”-shaped. Some might imagine that the extended approach is more accurate, but one might equally say that the rounded shape is more musically natural. In a particular system, one approach might be more complementary than the other. My overwhelming sense, though, was that differences in this area were more intellectual than musically essential. Call me a heretic, but my strong impression was that I could easily say one amp was more extended than another, but it didn’t factor into how musically involving the amplifier was.

As I let the sound of these amps sink in, the next thing I noticed was how each amplifier handled the representation of instruments in space. What became apparent rather quickly is that some of the amplifiers, particularly the Classé, present a deep soundstage perspective. In contrast, the Audio Research and the McIntosh have a more forward presentation. I say forward here, not in the sense of aggressiveness, but in the sense that you seem to be seated closer to the instruments. I don’t mean to seem wimpy, but it isn’t hard to imagine a group of people split over which approach is right. Depending on your system one could be either helpful or problematic. Because I use MBL speakers, which create a big, deep soundstage, I found that the amps with a deep perspective fit with what I expected, but the other amps didn’t really interfere with my listening.

I also noticed that the image specificity of each amp is different. I would call the Audio Research somewhat diffuse in its imaging, meaning that instruments are not presented with pinpoint placement. By contrast, the McIntosh is more focused in that instruments appear to have very specific locations. Possibly because of my speakers, I tended to prefer the more focused approach. However, I know from discussions with many reviewers on our staff that the diffuse approach seems more like what you hear in the concert hall, and that makes sense to me. In any event, I wouldn’t rate the differences on this dimension between these amps to be particularly large. For a really different approach to image specificity, you need to try a tube amplifier in my experience.

So, system-tuning is certainly abetted by amplifier selection. The only problem is that to do this you would be well advised to drop the idea that any given amplifier is better or worse than other amplifiers. In other words, you have to think about certain sonic parameters in a new way—a way that is less good-vs.-bad and more an attempt to get at the qualities being delivered. An example may help. Think of hair. You could think about it in terms of “dirty” or “clean.” One would be bad and the other good. That, I think is the way we normally think about audio equipment. But in the case of hair you could also think of “blonde” and “brunette.” Here we are talking about qualities, not about good and bad. You might have a preference, but it is hard to argue that one is universally better than the other.

So, with well-engineered modern amplifiers, you have to think in relatively neutral terms about what you really want to do. To illustrate how this might be done, consider my listening notes presented as three graphs: