My Thoughts on VSL
In the early days of my building (mid-90’s), I only built the Traditional model of dulcimer with a 28” VSL. For those that are unfamiliar with this terminology, the VSL or vibrating string length is the distance from the nut or zero fret to the bridge. That was a pretty standard length back then. For my dulcimer design, that puts the bridge back on the tail block very near the end of the dulcimer. The result is a very sweet traditional sound with lots of sustain and balance across the strings. Back then, the majority of dulcimer playing that I was familiar with was old time fiddle tunes with lots of strumming and not much chording. Finger and flat picking certainly existed, but were not nearly as prevalent as they are today.
In my opinion, over the years, the types of music commonly played on the mountain dulcimer has broadened significantly. There is much more flat and finger picking and even the music that is mainly strummed requires much more chording. With the longer VSL, the fret spacing is farther apart and for some chords, the stretch can be difficult. This is especially true for people with smaller hands or joint issues. So, over the years, we have seen shorter and shorter VSLs come into play. I first went to a 26.7” which made a good bit of difference but was later pushed to 25”. Also, with the shift in music style, people began to want a deeper richer sound rather than the sweet high sustain drone sound.
The bodies of all my current model dulcimers are the same length. As I mentioned above, the 28” VSL puts the bridge out on the tail block of the instrument. Keeping the body the same length and shortening the VSL pushes the bridge out onto the top of the dulcimer and away from the tail block. The bridge is one of the main elements that induces energy into vibrating the top and creating the sound. The area out on the top away from the end block is more flexible or unsupported. As the bridge is moved out onto this less supported area, three things happen. First, the energy from the vibrating strings is able to vibrate the top more so the instrument gets louder. Second, the less supported area has a lower natural vibrating frequency so the lower deeper tones are emphasized. Third, with the bridge farther out on the unsupported area, the sustain or “ring” decreases. All these things interact with each other so, as with most things, you end up with tradeoffs.
Around 2017, Stephen Seifert expressed interest in playing my dulcimers. He really liked the 26.7” VSL with its longer sustain for strumming. He really liked the 25” VSL with its deeper voice for finger picking. Through discussions with him, I decided to split the difference and try a 25.8” VSL. For him, it has been “the answer”. It is just the right mix of depth/warmth and sustain/ring. It also retains the ease of chording.
The 25.8”VSL has become my most popular build providing ease of playing and a balanced voice.