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New D670 Hammered Dulcimer: Super Bass on the Right and Left!

February 10, 2016
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The D670 is a solid-wood chromatic hammered dulcimer with an extended bass bridge on the right

After more than two years of research and development (and many prior years of begging and pleading by dulcimer players), we are pleased to announce the new D670 – our ultimate-chromatic-extended-range-super-bass-on-both-sides dulcimer!

The Backstory

Dusty Strings has been collaborating with Sam Rizzetta, dulcimer inventor extraordinaire, on dulcimer design since the 1980s. The first extended range D600 models were introduced in 1999, and with the subsequent development of the 4.5-octave D650 (which had an even lower playing range proposed by Dan Landrum), we sort of thought it couldn’t get any better. The 650 had a deep, rich and powerful voice, and playing it felt like playing a grand piano.

The only minor inconvenience was that, for optimal tone, the super bass bridge (the extended bass range) had to be positioned on the left-hand side of the instrument. Many players familiar with the traditional fifth-interval patterns would have found it more natural to reach those notes on the right side of the bass bridge, but Sam’s early tests found that since there wasn’t much freely-vibrating soundboard area on that side, having the bridge on the right produced a thin and somewhat lifeless tone. Over on the left side of the instrument, there was much more open space, and that proved to be a huge factor in the soul-satisfying bass voice that everyone loved so much. We turned down many requests for a super bass bridge on the right because our experiments with this matched Sam’s experience and to us, it was not worth the compromise in tone.

However, there were a few determined players who did not give up, and one of these was our long-time friend Ken Kolodner. For those that don’t know Ken, he’s a great fiddler, dulcimer player, performer, teacher and recording artist from Baltimore. Ken recalls, “It has been at least 20 years since I first played an extended range instrument. I knew immediately that I needed that lower range. From that very first moment, I also immediately thought it made a lot more sense to have the super bass on the far right and not the far left. Having the super bass on the far left sure seemed like a disruption in my hammer patterns. I approached various builders (Sam Rizzetta, Nick Blanton, Ray Mooers and others) about the feasibility and basically received the same answer – which was not an affirmative one! The story from every builder was the same: a super bass bridge on the right would be too close to the bass bridge, compromising the sound of the instrument and would make clearance of hammering notes in the area very difficult. Periodically, over the years, I asked Ray if he could reconsider the idea. You might say that I pestered Ray whenever I could!”

In August of 2013, Ken contacted us one more time to beg for this feature, and we thought, “What the heck, let’s give it another look!” When we turned to Sam to see what he thought, he told us about a concept he had tried before with some success.

“I designed a way so that the same Super Bass courses could be played on bridges at both the left side and the right side,” says Sam. “The right SB bridge was positioned to be playable but not interfere with structure or tone of the other bridges. And the left SB bridge was positioned for best tone, which is heard whether the strings are played on left or right.”

This idea had been implemented by a few other builders over the years, but it was fraught with complications, from the extra clearance needed around the bridges so the strings wouldn’t buzz to the difficulty of creating a damper system that could reliably damp the super bass notes. When we thought about this more, we realized that we now had tools at our disposal that could help us work through these issues. With the ability to do 3D computer modeling, we could more easily visualize the effects of minute changes in bridge design, and our CNC (computer numerical control) machining capability would allow us to consistently produce bridges with odd-shaped holes at precise angles.

We sent Sam a D650, which he modified to add a second super bass bridge on the right, and when we got it back and heard what it sounded like, we knew we were on the right track. With the two bridges sharing the same strings, a note played on the right-hand bridge activated the left-hand bridge and the big expanse of soundboard on that side, producing the same full, lush tone as the beloved D650. This also increased the versatility of the instrument, since the low bass notes were now within easy reach on either side of the instrument.

The Development

As Sam notes, “Adding Super Bass left and right is not a trivial undertaking,” which explains in a nutshell why the initial successful concept was followed by two years of development and testing.

If you’re not familiar with the term “crossover point,” it refers to the valley where the strings coming from one bridge cross underneath the strings coming from the opposite bridge. Having the crossover point halfway between the bridges maximizes the playable area on each side of the valley, so builders generally strive for that. Even minor changes to the angles of the strings can affect the crossover points, and when you do something as drastic as raising up the super bass strings with a second bridge so that they are more or less parallel to the soundboard and no longer at an angle, that throws everything out of whack.

The other thing you have to be mindful of when adding another bridge is that the existing strings need to pass through and around that new bridge with plenty of clearance so that they don’t buzz when played. The D650 has always stood up really well to hard playing, and we wanted to be sure the D670 would too.

One of our woodworker-engineers, John Dietrich, spent many hours building 3D computer models of the bridge arrangements, trying to work out those details. When he thought he had something workable, he gave the specs to our Mill Team to make a set of bridges, which then went to the Finish Team to be sprayed with lacquer and to the Post Production Team to be set up on a prototype instrument. Each new prototype was played and tested for several days by Ray, the results were reported back to John, who made adjustments to the design, and the process started again. Each cycle took several weeks.

Bass bridge and right-hand superbass bridge on the D670 hammered dulcimer

At the same time, we were experimenting with an entirely new way of making the bridges on our CNC machines, changes to the internal bracing were being tested, we were trying out different woods for the bridges, and a lot of time was going into the damper system design.

In theory, dampers are a very simple mechanism. Felt is attached to a bar, the bar is attached to springs, and some sort of string or cable pulls the bar down so that the felt contacts the strings and stops them from ringing. In practice, designing and installing well-functioning dampers is not so simple, and the more complicated a dulcimer gets, the more complicated the dampers have to be.

Because our Chromatic Series dulcimers have more strings and bridges than our basic models, adding dampers is already a finicky process of cutting and attaching felt pieces by hand, custom-fitting each bar to its particular instrument, and making minute adjustments to the position for optimal functionality. When we added the second super bass bridge, the only way to damp those strings was to extend the right-hand damper bar out past the bridge. This added a whole level of complexity to the design and the installation process, and also required inlaying black and white note markers into the damper bar itself, since the bar covered up the bridge markers.

D670 damper bars have an extension on the right-hand side to cover the superbass bridge

At long last, after two years of shipping prototypes back and forth from Dusty Strings in Seattle to Sam Rizzetta in West Virginia and Ken Kolodner in Baltimore, we have what we feel is the ultimate hammered dulcimer. We owe many thanks to Ken for his persistence, to his students for their feedback on the prototypes, to Sam for his brilliant ideas and analysis, and to a whole crew of Dusties for their tireless work, fine craftsmanship, and creative problem-solving. Below is the D670 development team surrounded by the first production models ready to ship. (Ken and Sam’s images have been magically inserted!)


Features of the D670

  • 4.5 octave range (extends down to A1)
  • 3.5 octave chromatic range
  • Super bass bridge on the right and left
  • Carbon fiber reinforcement for tuning stability
  • Full damper capability
  • Solid sapele soundboard and back

Building on the popularity of the D650, the D670 adds a feature that players have long been yearning for – the ability to play those low, soul-satisfying super bass notes on the right side as well as the left. The addition of the second super bass bridge to the right of the bass bridge puts those notes within easy reach for any arrangement that incorporates low bass, and it does this without sacrificing the tonal qualities that are so beloved on the D650. In fact, there is now a unique stereo-like effect, with the bass notes seeming to emanate from both sides of the instrument, a fun benefit for the player!

This model marks the debut of what we’re calling “the dual-density bridge system,” which was conceived, prototyped and named by our design partner, Sam Rizzetta. In the upper ranges, we’re making the bridges out of bubinga, a very dense and articulate African tonewood, which brings out the clear, ringing bell tones of the high notes. We’re using our standard Eastern hard maple in the mid and lower ranges, since we like the full, warm and round tone that the slightly less dense wood produces. We’ve found that this combination surrounds the player with a balanced blend of clarity, responsiveness, sparkle and warmth, and it will now be a standard feature on all our Chromatic Series models.

D670 hammered dulcimer bridges are made of two different woods for optimal tonal balance

For a few years now, our Chromatic Series dulcimers have had carbon fiber incorporated into the internal bracing, which makes the frame quite a bit stiffer. These instruments already had a reputation for staying in tune, but the addition of the carbon fiber reinforcement has made the tuning stability truly exceptional. When your instrument has 91 strings, this is a very exciting feature!

The D670 damper system is much more complex than on our other models and it takes more time to install and fit, but we felt like we couldn’t call this the ultimate hammered dulcimer without the capability to damp all the notes. At first glance, it looks like the dampers cover up the super bass bridge and it’s hard to believe you can actually tell what notes you’re playing, but players have said it takes very little time to adapt. There are black and white markers on the damper bar itself, and we’re hearing that some people learn to take their visual cues from the bass bridge as well.

If you’re wondering whether there’s a catch, there is (sort of). In the words of one new D670 player, “I feel like I am playing the hammered dulcimer equivalent of a concert grand piano.” This speaks primarily to the responsiveness, tonal balance, large range and deep, powerful sound, but those features are due in large part to the relatively substantial size and mass of the instrument. At around 27 pounds, the D670 is still portable, but we recommend limiting your walking distance!

If you’re thinking, “I would kill to have a lush-sounding super bass bridge on the right, but no way am I taking on an instrument that big!” then perhaps we could interest you in the upcoming and more portable D570… As the D670 is to the D650, so the D570 will be to the D550. Same sound, same range, same damper capabilities, but with those awesome low notes on the right! We are in the final stages of prototyping the new D570, and don’t know for sure when it will be production-ready, but we expect to announce it sometime this summer. Stay tuned!

See the full details of the new model.

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