[SoundStage!]Factory Tour
Feature Article
November 2003

Boulder Amplifiers Factory Tour
by Jeff Fritz and Marc Mickelson

Walking into Boulder Amplifiers, we wondered what could possibly go into a $36,000 stereo amplifier to justify its price. Even by high-end-audio standards, a $36,000 sticker price is stratospheric, so the natural skeptic in us was on the lookout for a possible explanation. If we didn’t see some extraordinary amp-building going on, we’d have a hard time reporting the details of this factory tour with straight faces.

But after spending a few hours with Jeff Nelson, Boulder Amplifiers’ head engineer and president, we came away genuinely impressed with what we saw. Now that we’ve witnessed firsthand what goes into designing and constructing the jewel-like components spanning the Boulder product line, we get it. If we communicate just one thing during this article, it is that the price tag on these products is matched by the company’s fanatical build quality and design expertise. As of right now, the only aspects of manufacturing not done in-house are aluminum anodizing and painting. Boulder does everything else.

Jeff Nelson comes from a 20-year-long professional-audio background, so a no-nonsense, bulletproof approach permeates throughout his product line. Long before the construction process begins, extensive design work takes place and involves an extremely high level of advanced circuit and enclosure engineering. Boulder products aren’t just pricey brutes; they're refined products for people with the scratch to afford them.

Boulder Amplifiers has embraced the digital realm, which is exemplified in the custom DSP and control circuitry the products implement. This requires an engineer to design, write, and implement purpose-designed software for each product and results in the unique ability of Boulder components to communicate with the end user. The 1010 ($11,000 USD) and 2010 ($36,000) preamplifiers and 1012 DAC/preamp ($16,000, shown right) display various messages that take system monitoring to a new level. For example, in the event of amplifier clipping, the large front-panel displays will let you know that you’re driving the system too hard. These messages are not only instructive, but come with nice touches such as exclamation marks! If you ever clip one of the massively powerful Boulder amplifiers, you deserve a harsh warning.


Jeff Nelson (right) is proud of his clean, efficiently laid-out factory, which includes manufacturing, testing, inventory, and shipping areas -- along with a completely separate machine shop.

 


Two Boulder technicians test a 2010 preamplifier, a process that takes 40 hours.

Scanning the parts bins, which are arrayed in orderly fashion.


All Boulder products are shipped in heavy-duty wooden crates, which the company always has in stock.

 


How are those artful Boulder heatsinks created? With CAD help, of course.

 


Boulder's machine shop has two Mastercam computer-controlled milling machines that cut and shape parts. Notice the stacks of aluminum billet on the ground -- this is how the parts begin.

 


Making sure that faceplate is just right.

Boulder machines its own parts jigs, which allow the company to turn out more and better parts for their products.

One advantage Boulder Amplifiers exploits is its in-house machine shop. While on the surface this may seem like it would affect cosmetic design only, we discovered that chassis parts are designed with intricate channels and compartments that interface perfectly with transistors, circuit boards (some the six-layer variety!), and other internal components. For example, the heatsink assemblies of Boulder amplifiers are machined with individual slots for specific transistors. According to Jeff Nelson, this enables thermal-sensing circuitry to more accurately monitor each transistor’s operating status. When the initial design can take into account such manufacturing capabilities, a much more complete approach to product development can take place.

Most impressive were the computer-controlled (Mastercam, for you tech types) aluminum milling and engraving machines for all the components’ casework. The aforementioned ability to machine interior parts with intense detail is matched by the outward sophistication of seemingly simple touches: The engraving process was specified to exact depths and dimensions so as to make use of ambient light. The result is that individual characters are easily readable. This obviates the need to fill the inner portions of each character with ink to enhance the visual effect. Boulder Amplifiers also creates many of the templates and jigs required for their construction needs. In this way, they actually mimic a much larger company’s production capabilities. The result of such painstaking sweat-the-details work is long-term durability and beauty.

Speaking of beauty, the heatsinks were mesmerizing. Don’t think these dimensionally intricate designs are just for show, though; the various depths and lengths of each channel are calculated so as to reduce chassis resonance at any given frequency, according to Nelson. And have you ever seen dovetailed joints in aluminum cabinetry? You will if you look at some of the Boulder Amplifier components. When you own the machine shop, you make parts as you want them to be -- even if it means hundreds of individual cuts and drillings for each product.

We’d be remiss if we placed all the credit for the Boulder mystique at the hands of advanced design -- there’s also the brute-force implementation. The 2060 stereo amplifier ($36,000, shown right) weighs 240 pounds. To see the interior of this beast is to admire its mind-boggling complexity. Two 2.5kVA transformers are potted in a nickel-plated steel case that runs the length of the chassis. The 80 output devices are clamped to the heatsink assembly via an aluminum bar damped by a Boulder-specified compound of which Jeff Nelson would provide little detail. And what about that power inlet? It’s a 32-amp 700V job that, according to Nelson, provides substantially more contact area than the standard 20-amp IEC most audiophiles are used to seeing.

Testing and measurement are not simply done once a component is assembled and ready to ship; they're done throughout the assembly process. This necessitates that the technician who constructs an individual component be not only skilled in assembly, but also able to conduct measurements using instruments such as an Audio Precision System One. This adds dramatically to the time it takes to build each component. For instance, the 2010 preamplifier (shown above right) takes 40 hours to actually assemble and another 40 hours to test. When you take into account that one technician spends two weeks on one component alone, you begin to understand the labor-intensive nature of Boulder Amplifiers’ products.

Listening to the sound system Jeff Nelson had assembled made it all come together. Clean, dynamically at ease, and pristinely accurate, the Westlake BBSM-10F speakers (shown above right) and BB10FSWP subwoofer were musically enjoyable driven by the Boulder electronics. The 2060 amplifier and 1012 DAC/preamp had it all under control regardless of the volume level.

Boulder has been in its present facility for five years and is considering expanding. The company is experiencing record sales, with many models backordered, according to Jeff Nelson. This is most impressive when you consider the cost of admission to such limited-production products. The $29,000 2008 phono stage sold in greater quantities in its first year of production than Nelson expected it to sell throughout its entire life. Surprising? Maybe. But then again, people have always been willing to pay for quality -- and Boulder Amplifiers products can be considered ne plus ultra.


To find out more about Boulder Amplifiers, visit www.boulderamp.com

 

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