Home Theater Equipment Review

October 1999

Anthem MCA 5 Multichannel Power Amplifier

It was at HI-FI ’99 in Chicago that I first heard the MCA 5 multichannel power amplifier. The amp was showcased as part of a home-theater display with Paradigm Loudspeakers. Sonic Frontiers International, the company behind Anthem, operates within the same corporate group as Paradigm, the large Canadian-based speaker manufacturer that produces a wide variety of excellent, high-value and high-performance loudspeakers. The Sonic Frontiers brand includes highly regarded tube amplifiers, preamplifiers and CD players for more esoteric users of two-channel high-end audio (although the company is showing prototypes of new solid-state multichannel products). The Anthem brand is more affordably priced, and although some of the products in that line still include tubes, it is here that the overall company began producing the higher powered solid-state amplifiers from which the MCA 5 was derived.

The "5" refers to the number of channels of power that this amplifier delivers. There are other options in the MCA series too. For people who want a similar amplifier but want it for stereo listening, there is the MCA 2. For home-theater users who want to split duty with their amplifiers and have one drive the front left and right speakers and another for the remaining three, the MCA 2 can be used along with a three-channel MCA 3. The prices of the MCA 2, MCA 3 and MCA 5 amplifiers are a very reasonable $699, $849 and $1399 respectively.

The move to separates

Many people use surround-sound receivers that incorporate the preamplifier and amplifier sections in one chassis. Many of these units are very good and can deliver outstanding value in a more convenient single-box form. However, separates have been popular in high-end audio for a long time, and for good reason. Many feel that to achieve the best performance, certain functions should be handled by separate components that have their own chassis, power supplies and such. As a separate power amplifier, the MCA 5 must be used with a surround-sound processor that will perform preamplifier functions along with decoding of movie and music signals.

Given its reasonable price, the MCA 5 will not only appeal to those consumers who have a separate surround-sound processor already, but also those who have a surround-sound receiver with preamplifier-output jacks. For those with receivers, the MCA 5 is an economical approach that makes for a fairly painless leap into the land of separates. Furthermore, for prospective buyers, the ability to compare the amp in your surround-sound processor with the separate MCA 5 is a snap, providing you have preamplifier outputs on your processor. If you do and if you hear the same type of improvement I did, I don’t think you’ll have too much trouble deciding if spending the extra money is worthwhile. I primarily used the MCA 5 driven from the five output jacks of my Nakamichi AV-10 surround-sound receiver.

Description

The MCA 5 is a hefty unit with a simple but elegant visual design. It comes with a black brushed-aluminum faceplate, about 1/4" thick, and has no heat sinks exposed at the sides. A silver faceplate is also available at no extra charge. Inside, all power-amplifier channels are on long cards extending front to back and with their individual heat sinks visible from slots in the top. The two large transformers are located to the front. There are single-ended RCA inputs as well as balanced XLR connectors on the back panel for each channel, and they’re positioned far enough apart to make hookup easy. I used the single-ended mode for all my listening.

The speaker connectors are a unique design that ensures no metal contact area is exposed. This is a safety requirement in some countries. These connectors are a solid design that can really be clamped down on the wire. However, the one downfall I noticed is that really thick spade lugs may not fit. I’ve noticed that this isn’t unique to the Anthem unit; spades don’t seem to work well in the majority of home-theater components I’ve had in-house. As a result, I now tell people to use banana plugs on their speaker cables (or fit banana adapters to their spades) or go raw with bare wire.

The MCA 5 includes a nifty auto-on feature that allows you to leave the front-panel power switch on all the time. With auto-on activated, the MCA 5 only really turns on when it senses an audio signal from the preamplifier. Likewise, it turns it off after a prolonged period when it senses no signal. Power-up in this mode is almost immediate, with only a small "tick" heard through the speakers as the amp is charging. I found the switch convenient and operated the unit this way most of the time.

Anthem rates the MCA 5 at 200Wpc into an 8-ohm load. This actually refers to each channel individually driven -- that is to say, one at a time. The company says that simultaneously driven (meaning all channels delivering power at once), the front left and right channels deliver about 190Wpc, and the center and rear channels about 170Wpc. The reason for the difference among channels is because of the way the MCA 5’s two output transformers are implemented. One of the two transformers is used for the front two left and right channels, and the other transformer performs duty on the remaining three channels. Into a tougher 4-ohm load, the amplifier delivers about 350Wpc, channels individually driven, and a bit less than that all channels driven at once. It’s important to compare apples to apples, so I was glad to find that Sonic Frontiers had these figures on hand. There are no real standards for documenting multichannel power output, so the consumer must beware. When comparing power amplifiers, it’s important to ask some of these basic questions so you know exactly what you’re getting.

For safety to the amplifier, the designers have implemented a sophisticated circuit that monitors both the output voltage and current as well as the operating temperature in order to protect the output devices. This maintains what they call the "Safe Area of Operation" for the amplifier. According to Sonic Frontiers, the circuit kicks in below 2.5 ohms. Unlike amplifiers that will simply attempt to drive harder and harder and produce more power, risking damage to the amp itself, the MCA 5 will diminish its power output into really tough loads. It doesn't cut the power completely; it just controls and reduces the output, which, according to Sonic Frontiers, is still 300 watts at 2 ohms. An amplifier manufacturer once remarked to me that speaker designers "just shouldn’t" design speakers that are too hard to drive because they create so much more unnecessary stress on the amplifier. Still, some do, and many amps don’t really like it.

The impedance issue should only affect a minimal number of potential buyers. My experience is that speakers whose impedance drops so low as to cause a problem are in the great minority, and usually esoteric designs. Furthermore, even if the impedance is low, given that the amplifier's output is still quite high, the low impedance may not be an issue. Obviously, some experimentation may be in order. The majority of speakers, probably more than 90%, including those from Paradigm, are loads between 4 and 8 ohms, which can be considered reasonable for most amplifiers, including the MCA 5. I have six speaker models in my house right now, and none would come close to being in this problem category. In any case, it’s a very good idea to ask, and if you’re in doubt with your speakers, it’s likely good to consult your owner’s manual or speak with the manufacturer of the speakers directly.

Given these ratings, the MCA 5 can be considered a high-power amplifier with more than adequate reserves for most users in reasonably sized rooms. In my own system, I used the MCA 5 with a five-channel system from Audio Specialiste whose impedance is rated at about 6 ohms. The MCA 5 had no trouble delivering high power to the speakers, resulting in excruciatingly high levels that I would never consider for pleasure. I could hear no distortion that would indicate that the amplifier was being pushed even close to its limits.

Sound

I’m not one who believes that all amplifiers sound the same, but I do believe many of today’s high-quality solid-state amplifiers, when properly designed, sound quite similar. It came as no surprise, then, when I discovered that my system with the MCA 5 sounded exceedingly clean and detailed with plenty of power and excellent frequency extension on both ends. What was surprising, though, was the amazing improvement heard over the all-in-one Nakamichi AV-10.

The AV-10 is rated at 100Wpc, and although 100 watts is sufficient power for my home-theater system, if I really want to push it exceedingly hard, I can make it hit its limits. As good a value as it is (and it is), there’s a definite ceiling to its performance. As expected, with about double the power, the MCA 5 can go louder, much louder, without a hint of breakup or loss of control. Sometimes people mistake speaker distortion for what is really amplifier distortion if they are really pushing the amp. With the Nakamichi, I could hear its distortion in my system.

The Audio Specialiste speaker system proved able to play much louder and remain cleaner than previously imagined when driving it with the MCA 5. Bass, again likely because of the MCA 5’s high power output and perhaps because there is increase in power-supply reserves, was much tighter, more detailed, and thundered with much more control. Titanic, which was just released on DVD, has subterranean bass that shakes the room through my front-channel speakers even without the subwoofer hooked up. Desperado, a favorite of mine for its almost relentlessness recording of gunfire and crashes, was rendered full-tilt with startling precision and authority. Music with heavy percussion was much weightier and tighter. All in all, the sound was not only louder, it was more dynamic and tighter. Given the increase in scale of performance I attained, it was as if I had stepped up a full "size" in terms of speakers.

Besides delivering more power, the MCA 5 was a step up in terms of refinement too. I summarize the sound as being exceedingly clean and tight without being the least bit bright or edgy. The MCA 5 sounds fast and transparent, meaning it paints a vivid sonic picture that has excellent clarity. As well, this amp is quiet, perhaps quieter than any other I’ve heard at its price point. As a result, resolution seems to be stepped up some. Dialogue is more intelligible, and subtle nuances that seemed masked in a more grainy, woolly sound are more apparent and distinct. From top to bottom of the frequency spectrum, there was a cleaner more lively sound that brought more excitement to soundtracks. While the compressed digital format that surround sound relies upon is hardly the ultimate test in assessing refinement, rest assured that I played plenty of music CDs, and the same type of improvements were heard. In fact, I heard nothing in the performance that would indicate that the MCA series of amps could not be used for music listening alone. Obviously you don’t need five channels of power for a stereo system. If I were in the market for a two-channel music-only amp, I would certainly give the MCA 2 a listen given its very reasonable price.

Conclusion

It’s really hard to get excited about power amplifiers because their function, while vital, seems just so mundane. Unlike surround-sound processors or even DVD players, amps have no whizzy features that are fun to play with. Input and speaker connectors, despite being unique, are rarely all that exciting. The auto-on switch, while exceptionally convenient, is hardly a rush. Still, the MCA 5 is able to deliver unexpected thrills that I guess would cause people to call me a certified techno-geek. In fact, when I first saw it at HI-FI ’99, discovered its price and heard its sound, I knew that it was one of the more exciting products that we would see this year. What’s more, Anthem has a surround-sound processor scheduled for release later this fall. Should its performance be on par with what the MCA 5 offers, it will undoubtedly be a killer combo. But for that we’ll have to wait.

If you are shopping for a separate power amplifier for a home theater, you should put the MCA 5 on your list, particularly if you are shopping for something more expensive -- the performance offered here may surprise you. In this price range there are just a few power amplifiers that offer exceptional value and performance, and the MCA 5 leaps alongside this elite pack. And for those who have a single-box surround-sound receiver, you should really take note.

If you are thinking about how to move your system to the next level of performance and are even considering buying new speakers, the MCA 5 may be really your ticket. In my system, it offered the type of improvement you get when moving up a notch to a larger speaker model in a company’s product line. Furthermore, the improvement in terms of refinement of sound moves the quality of the whole system up too. Quite simply, the $1399 price is very easy to justify. The MCA 5 offers excellent performance at a price that begs for auditioning.

...Doug Schneider
das@soundstage.com

Manufacturer Contact:
Sonic Frontiers International
2790 Brighton Road,
Oakville, Ontario, Canada.
L6H 5T4
Phone: (905) 829-3838
Fax: (905) 829-3033

Website: www.sonicfrontiers.com/anthem

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