levers on a dulcimer?
General mountain dulcimer or music discussions
I've never seen a lever placed between the bridge pic and the tuning lever. That must be a new design. All of the levers I have seen and used are meant to be mounted on the neck of the harp in between the bridge pin and the sound board. When the lever is raised it comes into contact with the string and creates a new , temporary break point in the string, raising it a half step. When the lever is lowered the break point goes away and because the string is now free to vibrate at it's original length it drops down to it's original pitch.
Although there are several different brands they all operate on one of two methods. The first is a single contact point style where a rotating cam on the lever raises a small bar up under the string, lifting it slightly and thus creating a new break point. The second style is a bit more complicated in that it uses a pair of pins. One is either fixed and lies just below the string....when the lever is activated it cause a moveable pin to drop down onto the string, pushing it down onto the fixed pin and then creating a small bend just beyond that fixed pin which gives it a break angle.
On the second two pin method, both pins move, one up and one down as the cam rotates. The easiest way to describe it would be to picture the face of a clock with the string running across the face from 9 to 3. the normal bridge pin would be off to the left of 9 and the sound board would be off to the right of 3. There would be one pin sticking out of the face of the clock at 4 and another at 10. When the lever is activated the clock face would rotate counter clockwise causing the pin at 4 to move to what would have been the 2 position and the 10 pin moves down to 8. The 2 o'clock pin becomes the new bridge (and break point).
In any case though, the change in pitch comes form a shorter VSL.
Now, all that being said, it would be possible to design a lever that could change the pitch, but it would have to be done by changing the string tension. For example, if there was enough room between the bridge and the end of the instrument you could put such a lever there that when activated would press down on the string. You could do the same thing at the tuning end on a flat head if there was sufficient flat surface to mount the lever. The problem I foresee is that of being able to control the amount of tension. On a harp the lever is either fully up or fully down....anything in between is likely to cause a buzz (not enough break) or incorrect pitch (break point in the wrong place) . I suppose you could install a standard single point lever so that when not in use the lever handle is up....just the opposite of how it would be on a harp. That would put the the pin above the string. Then by lowering the lever handle you cause the pin to bend the string down toward the fret board (if mounted behind the bridge) or peghead (if mounted between the nut and the tuner) That would make the string go sharp. But how much do you need to push down? Every string is going to be different, and even the base pitch of the string will affect the amount of "push" needed. IN other words, you could have it set up perfectly to change a d to a d# but if you tune down to a c and then used the lever to try to raise the pitch to a c#, it probably would be off.
BTW Dusty, is it possible you were looking at a wire strung harp? Those don't usually use a bridge pin with the string running right from the sound board to the tuner. That might explain what you saw.....a sharping lever with nothing between it and the tuning pin.
Dusty Turtle said:
Remember that the ones I saw this morning were onharps, so perhaps bridge is not the right words. In one case the leversbasically acted to pushon the string on the non-vibrating side of a metal post around which the stringbent just before it hit the pin, thus tightening the string. They did not seem to be adjustable, but they were not all identical, meaning there were different size levers for different strings. Another type hadits own horizontal metal bar on the lever itself. When the lever was engaged,it pushed on the string just past that metal bar, again tightening the string. Those,too, did not seem to be adjustablebut were different sizes.Obviously, the degree of precision here is pretty high. My cousin's harp--which I only saw one inebriated evening and did not examine closely since the idea had not yet occured to me touse these contraptions on another instrument--has levers that can be adjusted for each string.They may indeed be the kind that shorten the VSL.
For the record, I did a quick search online too, and the only prefabricated levers I could find that were sold independly of a harp were intended to change the VSL, too. That might be what my cousin has and as you've all pointed out, they would not work on a fretted instrument.
If it would be feasible at all to design a lever for use on the dulcimer, it would obviously involve a lot of work to get it to fit exactly right. My uncle makes autoharps (and puts fine tuners on those) and perhaps I'll ask him if it would be possible todesign something. Maybe the only reasonable use would be as Bobby said to change the tuning of the melody string so you could switch modes in the middle of a tune or medley. But I still like the idea of something resembling a whammy bar that could alter a string by a 1/2 note and then drop it back down. I guess I'll keep dreaming.