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McIntosh MC352 Amplifier

05-08-2017 | By Editors at Positive Feedback | Issue 89

This article, by Victor Chavira, Larry Cox, and Dave Clark, originally ran when audioMUSINGS was in print - Issue 15, 2001

McIntosh Audio Labs MC352 Amplifier

McIntosh Audio Labs is a classic American company. Since 1949, McIntosh has remained true to its design aesthetic: bullet proof build, black glass, chrome, and big blue meters. The MC352 is their 350 watt stereo power amplifier. Several things set it  apart from the pack of solid-state muscle amps. First, the MC352 sports output transformers, like a tube amp. In tube amps, the trannies serve to lower the power tubes' high impedances to speaker-driving levels. In the MC352, the patented McIntosh Autoformer matches output impedance for a given speaker load. The MC352 has taps for two, four, or eight ohms. Sentry Monitor and Power Guard circuits protect the amp and reduce distortion. The MC352 is a double-balanced push/pull design that achieves remarkably low distortion levels (.005%) across its power band. Lastly, the MC352 is a massive and visually striking piece of electronics.

The Big Mac (sorry!) was plugged directly into an AC outlet. Since I do not own a preamp, I connected the variable output of my CD player to the RCA inputs of the amp. Power was fed to the Maggies from the Mac's four-ohm taps. The big blue meters were amusing to the point of distraction, so I turned them off for critical listening. No break-in time was necessary, since McInstosh sent us a factory-refurbished amp (although, with build quality like this, I can't imagine what would need refurbishing).

The most compelling aspect of the MC352's performance in my system was its effortlessness. Music was discharged into the room with incredible speed and authority. Bass response was unparalleled. Ron Carter's Under Gray Skies sounded better than ever, with each bass note clearly defined and pitch perfect. Music filled the room with energy that was felt in the floorboards as well as heard by the ears. The MC352's control over the Maggies was complete. In the 1.6s, all sounds above 600Hz. are produced by the quasi-ribbon. With much of the critical midrange and all of the top end produced by a single line source, it's no wonder that the Magneplanars are noted for their seamless musical perspective. The responsiveness of the quasi-ribbon when connected to the MC352 was truly exceptional. Notes cut through the air with a precision and clarity reserved for much more expensive speaker/amp combinations. Of course, big amps and big speakers make for big sound. However, small-scale music was intimate and engaging. Natalie Merchant is one of my favorite artists. Her voice was drawn with a subtlety and warmth that is rare in high-stakes amps. Is 350 watts per side necessary to accurately render a classical guitar? Probably not, but the MC352 gets to the heart of music from the first watt to the 350th.

The McIntosh/Magneplanar pairing was magical. The MC352 is a remarkable product for its power, extremely low distortion, transparency, and non-fatiguing sound. Now, if you don't mind, I'm going to turn the meters back on and enjoy the show. Victor Chavira

My dad had a McIntosh tube amplifier in the 60s. I remember that amazing blue faceplate, and the turn-on process. After a couple of minutes of whirring and crackling, music came through the speakers, and it was darned musical! When the transformer failed in 1970, my dad tossed the amplifier in the garbage. I remember having a pang of anguish. When I mentioned it to him he replied, "That's the whole amplifier," that is, the transformer gave the amp its character. He bought a solid state Dynaco integrated, and said it was much better than the Mac, meaning, I guess, that it was more linear. I remember, though, that he listened to a lot less music after that.

I recently spent some time listening to a McIntosh MC352 amplifier. At 350 watts and about 180 pounds, this is one large hunk of audio gear. When I looked at this beast sitting in my living room, the brick #! house metaphor came to mind. The build quality is exemplary, probably the best I've seen. For your $8000 you get attention to detail, great fit and finish, as well as a bucket of watts. This is a first class product. McIntosh amplifiers still have the bold blue dial, as well as the huge meters, which tell you how many watts are pumping through your system. If you don't want dancing meters and flaming blue lights, they are defeatable. Though it is not delicate or subtle, there is a distinct appeal to the bold and plain visual style of this amplifier. I was somewhat overwhelmed by its size and weight, but I really liked its looks.

I recently sold my Oracle Delphi (I kept the Koetsu!), and haven't replaced it yet, so all I had for a reference was my horrible little Pioneer DV 525 DVD player, but I had just completed reviewing the Theta Pro Prime DAC and Carmen DD/DVD player. In my system, the Theta duo had a full bottom end, which compensated for the Pristine's inability to really go low. I figured I'd cheat and hook up the Mac amp with the Theta stuff. You'd think that this collection of audio heavyweights would result in audio bliss, but you'd be wrong.

The huge, powerful bottom end I heard with the Thetas in my usual system disappeared... it was tamer and less full, though certainly not constipated. The tight, fast bottom end I expected 350 watts to provide didn't materialize. Damn! The Chord SPM1200B, a mere 250-watter, had grabbed hold of the bottom end of the ATCs and shaken it. Not so the Mac. Transients became flaccid, attacks didn't attack, dynamics were moving too slowly to be noticed. Tonality, something I prize above everything else, was nothing special. The overall sonic impression was unengaging.

However, with the $200 Pioneer in place, the bass perked up, in fact it got downright snappy, with a tautness simply missing with the Theta gear, and missing from my reference system's performance with the Pioneer. Who'd have thought that the lowly Pioneer could exceed $5000 worth of Theta gear? Certainly not me. The top end revealed recording quality, good or bad. The midrange, while superior to the Theta's, was not rich, full-bodied, or "liquid." The sound was not open, but it was detailed, with very little "art."

I just wasn't taken by the performance of the McIntosh amplifier, and I feel I should have been. It may be that the mighty McIntosh just showed off the pedigree of my Pioneer. If I still had my Oracle, I could have tested this thesis, but I don't, so I couldn't. I should tell you, though,  that I tried the $5500 GamuT amplifier with the crappy little Pioneer, and had a remarkable sounding system. The McIntosh grabbed the bottom end better than the GamuT, but that is about the only way in which the McIntosh pushed the GamuT aside. The GamuT was just amazingly detailed, tonally rich, and sweet, sweet, sweet on the top. In fairness, the GamuT is the most desirable amplifier I've heard in my system. I have mixed emotions about the McIntosh. Larry Cox

To let the rabbit out of the hat, it is one of the best I have heard so far in the Clark system.

My first encounter with McIntosh was back when I was fifteen and babysat for friends of my parents. They had an all-McIntosh system with AR 3Ax speakers. For a teenager using an all-in-one system of long-forgotten heritage, this was an eye-opener. Bass, dynamics, and just about everything else were new to me. I had yet to hear music like this in someone's home—live, yes, but not through a pair of speakers in a living room. I sat for hours just looking at those beautiful components, all lit in blue, and listening to whatever station the tuner was set. No way in hell was I going to cue up a record! The experience was the impetus for me to venture onto the audiophile pathway.

Not much has changed in the McIntosh world since then. Looking like it came from the 60s, with the classic blue meters and glass faceplate, the MC352 is a big amp in every way—size, weight, and power.

The amp exudes an elegance sorely missing in today's "just-another-black-box" designs. The MC352 is fully balanced from inputs to speaker outputs. Two matched amplifiers per channel operate in push-pull with their outputs combined in the "output autoformer" McIntosh has built its reputation on for the past gazillion years. Each amplifier contains complementary balanced circuitry, and the resulting double-balanced configuration cancels virtually all distortion. The autoformers allow the amplifier to output the same power into any load with the greatest purity.

My current amplifiers are the Clayton M100s, which offer 100 watts (when set to high bias) and a class A topology. They are a step up from their previous 70-watt incarnation as the M70s. The increase in power has opened up the Reimers, allowing the music to be considerably more dynamic and expressive, with an ease that is quite startling. Bass slam and power have also dramatically improved, bringing music that features the fundamentals to a whole 'nother level. We were quite amazed at how just thirty more watts could transform what was already, to us, a great music system. It is now one that we, plus a few others, consider to be of reference caliber. Is it perfect? No. A bit more transparency in the midrange and treble would be most welcome, and perhaps a notch more dynamic headroom. A bit less bloom in the upper bass and a more slam in the lower bass would also be nice. A matter of swapping cables, preamp, source, or amplifier? Or is it simply a matter of what 350 watts can do?

In many ways, the Claytons and the Mac 352 are alike. Both amplifiers are very powerful and dynamic, and both are extremely dimensional, with a full and rich soundstage. Images are well delineated, and exist in an airy space. Neither amp is the least bit grainy, lean, or overly analytical. Bass is extremely deep and powerful. Tone is very much "right-on," presenting a room full of natural-sounding instruments. Does either sound like the real thing? Only the real thing sounds like the real thing, but both of these amps bring me awfully close, or at least close to what I interpret to be the real thing from my memory of it, and for me, that is all that matters. Both amplifiers offer the listener a very un-solid-state-like presentation, sounding like the best of tubes mated with the best in transistor technology. Inexpensive they are not, but I have heard many amps that cost considerably more and offer less.

As good as the Claytons are, however, the McIntosh may have raised the bar. Let's be clear about this—350 very good watts is better than 100 very good watts. In the case of the MC352, more wattage resulted in slightly less "fullness," or warmth, resulting in an improvement in speed,clarity, and openness. Images take on a greater sense of life, the "performers are here" quality that is so sought after. Bass came across as a bit faster and less full, without being any less extended. None of this is drastic in the least. Differences were more apparent on one disc than another, with one amp preferable in some cases, the other in others. The Claytons sounding warmer and richer, the MC352 leaner and faster. All of this was more a matter of taste than anything else—make that more a matter of sheer power than musical superiority.

Now, it is possible that these differences are the result of different topologies rather than a matter of sheer power, or perhaps a combination of the two, but if I were a betting man, I would say that most of it was the result of the increase in power. Why? At lower volumes, the two amps sounded way more alike than different, but as the volume increased, the MC352 pulled away.

I really enjoyed my time with the MC352, and found there to be nothing to criticize in terms of its musicality. The amplifier performed flawlessly for many weeks and never created the urge to switch back to the M100s for musical relief. Nice. Dave Clark