Solid State Power Amp Reviews

When I was offered the opportunity to review a Burmester product—the 216 stereo power amplifier—I accepted immediately, mainly out of curiosity. Berlin-based Burmester is an important hi-fi brand, but I knew very little about the company and their products. What better way to learn more than to review one of their products?

Burmester's creation story
When you're building a hi-fi system, there's something right about starting with the preamp. It just makes sense. It's what Dieter Burmester did in building a hi-fi company.

The preamplifier is the operational hub of any hi-fi system (not counting systems that don't have a preamplifier), but that doesn't fully capture the preamp's import. The preamp is the brain but also the brainstem, the spinal cord, possibly the heart. Its impact on a system's sound may be less obvious than that of the loudspeakers, but that impact is nonetheless fundamental, with emphasis on the root word, "fundament": ground, foundation. ("Fundament," I've just learned from an online dictionary, can also mean a person's buttocks. Please try to forget that.)

Burmester started up in 1977 with the 777 preamplifier, which, as you can tell once you know Burmester's nomenclature, came into existence during July (the seventh month) of that year. Dieter Burmester, an engineer and the company's founder, was working in the medical equipment field as a consulting engineer. Dieter was also an audiophile. He was impressed with the performance of certain op-amps used in his test instruments. He assembled the 777 out of medical-equipment parts.

That's a piece of the Burmester origin story: The preamp came first, was fundamental. But every interesting story can be looked at from different points of view. Looking at it from another point of view, the history of Burmester goes back to an earlier point in Dieter Burmester's history. Dieter Burmester was a guitarist. His first instrument was electric bass. His tubed bass amplifier failed frequently. He studied electronics to figure out how to fix it. In time, he qualified as a radio and TV repair technician. Then he built his own, more reliable bass amplifier to take to gigs—and that was the start of his career in sound and electronics. If my math is right, this would have been around 1962, when he was 16 years old. You could trace the company's history back to that. Bass, then, is fundamental: the second fundament.

Returning to that preamp: Dieter was happy with the 777. He decided to set up a company. But the bank he approached for financing was skeptical. It doubted a lone engineer with little business experience could compete in a space dominated by big corporations. They chose not to give him his loan. So Dieter went ahead and built some preamps—20 777s—with his own hands and soldering iron. He sold them to friends at what was, for the time, a high price; online sources say the 777 cost as much as a car. Apparently, Dieter had wealthy friends, quite a few of them. The friends who bought the 777 were happy. That preamp must have been good.

Those 20 preamplifiers funded the company, no bank required. One of them made its way to a prominent Berlin hi-fi dealer, where a prominent critic for a prominent hi-fi magazine noticed it. (Getting noticed by a critic for a well-known hi-fi magazine is, as we all know, the key to success in this industry.) The following year—1978—Burmester GmbH was founded.

Told from this perspective, the next theme of the story—Burmester's third fundament—is the high-end thing. When it comes to luxury-class hi-fi, Burmester is no Johnny-come-lately. Burmester products were always expensive.

For a while, preamplifiers remained at Burmester's core. The company's second product, the 785, was also a preamplifier. It was quite different from its predecessor, smaller and simpler. The 777 had many knobs—tone controls, which could however be bypassed for those seeking purist sound. The 785 had separate left-and-right level controls—a balance control, in effect—plus the essentials: volume control and source selection. It was a bare-bones preamplifier.

From the 777 to the 785, the change with the most long-term significance was aesthetic: The 777 had a striking gold finish. The 785 was silver with a mirror finish. That finish became the company's aesthetic signature. I've never asked, but I suspect the finish was intended to send a message. "Transparency" isn't quite the right word—mirrors aren't transparent—but it's close: Burmester products reflect back at you whatever is on the recording.

Those early preamps, then, established the company's value system.

What about amplifiers?
Burmester's amplifier legacy is newer and less well-documented than that preamp-based origin story.

The first Burmester amplifier I recall knowing about was the 909, introduced in 1990. The 909 was quickly followed by the 911. Both were stereo. Simon Pope, who handles press relations for Burmester, told me that two amplifiers preceded these, both monoblocks: the 828 and the 850. The 850 was unique in that it came in two versions, one for speakers with nominal impedance of 4–8 ohms, another for 10–20 ohms. In an email, Pope described these early amplifiers as "aesthetically quite quirky" and said they "bear little resemblance to current products in the way that the 909 does."

The 909, then, was the origin of modern Burmester-amp DNA, while the smaller 911, introduced two years later, is the obvious ancestor of the amplifier under review, the 216, although there was a model in between, the 956.

The immediate predecessor of the 216, though—the 216's daddy—was the Burmester 159.

The kick inside
What this means in terms of technical design—circuit topology and so on—isn't completely clear. Pope took several of my more technical questions back to Burmester's engineering department, which sent back answers. Those answers are informative even if they don't quite add up to a whole, simple, technical story. Certain design principles are clear. Burmester believes in balanced/symmetrical design, direct-coupled input to output. The 216 possesses those attributes.

When I asked what had changed from the previous generation—from the 159—the first point made by the engineering team had to do with the "thermal concept," referred to elsewhere as the "cooling concept." In the 216, "there are now universal heat pipes that allow us to keep temperatures constant and low at any point within the cabinet. These allow for better thermal management, which gives us more freedom in design and helps [increase] the lifespan of the power amplifiers."

Other changes have resulted from the availability of new technologies, such as the microcontroller used in the protection circuit, which allows operation to be monitored from outside the signal path. "This allows us to achieve the operational reliability expected from a Burmester power amplifier that can easily handle difficult loads and creates effortless power delivery." Documentation I received includes a few other interesting details, such as "silver cable in the input section." Silver has higher conductivity than copper, but the difference is very small. Many claim that silver has a characteristic sound; some like it, others don't. Certainly silver is consistent with the Burmester design aesthetic.

Other points from the design brief apply to both the 216 and its 218 big brother: They must be bridgeable to mono. They must remain short enough to fit on a standard component rack, since that's where many customers will want to put a stereo amplifier, in contrast to monoblocks, which can happily sit on amplifier stands.

The new amplifiers incorporate Burlink, which, the internet says, is either the shuttle service run by Burlington County, New Jersey, or Burmester's proprietary system for interconnection and control. I'm betting on the latter. A remote-control On/Off function was implemented with the new amplifiers, as was an Auto-Off feature. Features like this are at once unimportant and, in the new world we live in, obligatory.

What else should I say about the 216 before I start listening to it? It doesn't heat up my listening room much at idle, and it doesn't run up my electric bill as much as some other amplifiers have, even with two of them running, bridged for mono. I conclude from this that the output stage operates in class-AB.

The Burmester website lists basic specifications, like power output; some others appear in the owner's manual. I've placed these in the Specifications sidebar. Here are some of the important ones. In stereo, the 216's maximum output power is 100Wpc continuous into 8 ohms, 165Wpc into 4 ohms, and 245Wpc into 2 ohms. Continuous power when bridged to mono is quoted only as a maximum: a formidable 490W—no load impedance mentioned. In response to a query, Pope told me it was safe to report that when bridged, the 216 is capable of doubling the stereo output. For more on the 216's technical performance, see the Measurements section.

Regarding that relatively modest power specification: Experience convinces me that power needs are consistently overestimated. As I write this, I'm listening with a different amplifier, which possesses an accurate power meter, with the same speakers I have used to audition the 216, the Wilson Audio Specialties Alexx Vs. I'm achieving 80dB average listening levels with less than 10W. The "cruising" level for this system for serious listening—not background levels—seems to be around 30W, with slightly higher peaks. At 100W, I'm consistently exceeding 95dB; I would not want music any louder. At this level, with nominal 4 ohm speakers like these, the Burmester 216 has power in reserve.

On the other hand, these Wilsons, while not an easy load impedance-wise, are quite sensitive. With less-sensitive speakers, it is possible you'd need more power.

There's a second way in which power requirements are overestimated. Even when you have, on paper, too little power, the results can still be satisfying.

A frequent misunderstanding is that maximum power affects bass response even at modest listening levels. Theoretical power limitations have no effect on the sound until the power runs out.

Setup
There's not much to say in this section except that Burmester sent along two 216s. With the assistance of Pope, who stopped by for a visit, I installed them in my system this way (as monoblocks) in place of the previous monoblocks, two Pass Laboratories XA60.8s—and cabled them up. I had at least one (and often two) Burmester 216 amplifiers in my system for the better part of a year, removing them occasionally to listen to a different amplifier for a while or to send them off to a Burmester dealer for an event. I became very familiar with the sound of these amplifiers, in stereo and monoblock configurations. Everything else you need to know about setup, you can find in the Associated Equipment sidebar.

Listening
There's an irony inherent in high-end power amplifiers: You pay a lot to get as little as possible—as little character, that is. This is how it should be in principled hi-fi, and it's often how it actually is. That's one of the things I respect about this hobby. Sure, some folks are aiming to impress their friends with something that catches their attention, but the true enthusiast—and there are plenty of them out there—wants a system that gets out of the way of the music, and they're willing to pay to get it.

This must cause marketers at high-end audio companies serious headaches. How do you stand out from the crowd when the goal is to hide? What other business can you think of where the goal is to make the product disappear?