Luthier Steve Rossow learned to build instruments the old-fashioned way: by hand, right here at Minnesota State College Southeast. After earning diplomas from the Guitar Repair & Building and Violin Repair programs in 2002, he set up his own shop in St. Paul building, restoring and repairing fine violins.

Now an instructor in Southeast's second-year guitar construction program, Steve knows and respects the techniques that countless generations of builders employ to build world class instruments.

But as an expert in CNC (computer numerical controlled) machining of violin parts, he recently teamed with radiologist Steve Sirr and luthier John Waddle to build a precise digital replica of the famous "Betts" Stradivarius violin, a 1704 instrument in the collection of the U.S. Library of Congress.

The project began with a set of detailed CT scans of the original Stradivari violin. Steve then took the information from the CT scans and made accurate copies of the wooden parts of the "Betts" using a specially designed CNC machine.

How precise? Steve was able to replicate details such as the density of the wood, the wear from players' hands, and the warping of the wood around the sound post. "Using CNC, you're able to create an actual digital replica of the real thing," Steve observes.

It may sound like something out of Star Trek, but of course you can't just turn on the machine and expect a perfect violin to emerge. A great deal of hands-on work is required to complete a violin, including scraping and sanding the wood, assembling all of the parts, applying varnish and setting up the instrument.

In 2011, Steve brought his CNC violin parts to the Violin Society of America's 2-week summer workshop at Oberlin College, where are some 50 luthiers collaborated to build the first replica "Betts." The violin was varnished at the 2012 summer workshop. Now known as the "Oberlin Betts," it was purchased and then donated to Library of Congress Music Division.

Last April, Steve, John Waddle and Steve Sirr traveled to Washington D.C. for a ceremony honoring the donation of the Oberlin Betts violin. It was a rare opportunity to compare the replica and the original "Betts" and hear both played.

Violinist Gregory T.S. Walker played the modern violin in concert and says, "The Oberlin Betts is a memorable instrument, masterfully set up to optimize expressive lower frequencies and seamless balance between the strings. It is perhaps even better suited to contemporary music like George Walker's Bleu, which I premiered with it at the Library of Congress, than an actual Stradivari would have been." 

Even better than the real thing? Listening experiment in NYC

Steve and John have worked on 3 additional CNC-based replicas of the "Betts." Last March, one of them was selected for a controlled double-blind listening test in New York City. 3 Stradivari violins and 11 modern violins were played for a panel of expert judges. The violinists stood behind a backlit screen, wearing darkened goggles so they did not know which instrument they were playing.

The judges rated the instruments for richness in the low end, brightness in the high end, overall preference and whether they thought it sounded like a Strad or new violin.

Steve and John's instrument was preferred by the judges over all of the Stradivari violins! Their violin tied for 3rd place in the overall scoring.

"Some people have been surprised that modern violins could sound as good as a Stradivarius, but in well-documented tests, this has been proven to be the case. It simply isn't true that old violins always sound better than new ones," says John Waddle.

Steve brings his now world-renowned expertise to his classes in the 2nd year guitar lab at MSC Southeast, where students build archtop guitars and mandolins. "It takes countless hours and late nights to carve out an instrument by hand. Used correctly, the CNC machine can be faster and more accurate," he says. "But you still have to learn how to make an instrument the old-fashioned way before you can expect the process to happen on the CNC machine."

Photos: Steve Rossow (Katryn Conlin); CNC machine, Oberlin Betts & Betts Stradivarius (Courtesy John Waddle, waddleviolins.com)