A different sort of BIgsby

[Mark Hammer]

I was given a guitar by a former co-worker that is a remarkably authentic copy of a hollow-body Mosrite combo. It has the German carve, stylized headstock, and other features seen in this other Japanese-made copy from the late 1960's.

Like this copy, and the various others, it has a cast-aluminum Bigsby-style vibrato and accompanying roller bridge. What is different about the unt, however, is that the strings are anchored in the vibrato arm at different heights. Specifically, the E and G strings are inserted into the base of the assembly higher than the other 4 strings, as can be seen in this picture, and the 3 lower strings are inserted at a bit of an angle. I'm curious as to what the rationale was for this arrangement. At first I thought it may have been something wrong with the one I have, but the picture indicates this was found in other units as well.

[Mick Bailey]

That looks like a nice guitar and one that I'd be more than happy to own.

My thinking with the hole arrangement is that it could be a form of tuning compensation. The stings further from the pivot have a comparatively greater arc to move through for a given movement of the arm. That is, I think the strings further from the pivot will flatten more than ones that are closer when the trem is dipped.

[rjb]

My thinking with the hole arrangement is that it could be a form of tuning compensation. The stings further from the pivot have a comparatively greater arc to move through for a given movement of the arm. That is, I think the strings further from the pivot will flatten more than ones that are closer when the trem is dipped.

I was thinking the same thing, but haven't figured out what kind of string set would require more travel for the 3rd and 6th strings. If I'm not mistaken, you would want more travel for strings with less tension. For instance: With a set of E.B. Slinkys, while maintaining approximately the same spacing between the strings, you can bend a major third on the 3rd & 2nd strings into a minor third - because the 2nd string has lower tension than the 3rd string. If you go old school, say a set of .013-.052 Black Diamond round wounds, tension is pretty consistent across the board (going by D'Addario's string tension chart). I haven't checked tensions for any flatwound sets.

http://www.daddario.com/upload/tension_chart_13934.pdf

-rb

[eschertron]

The offset hole choice seems all wrong to emulate a pedal steel (oblique) bend

[Mark Hammer]

Given the era of the guitar, I'm wondering if the hole heights weren't arranged in anticipation of a flatwound set.

I suspect more clues to the purpose behind the offset holes could be found by identifying what other guitars used a similar scheme.

[rjb]

How about break angle? Any reason to want different break angle on different strings? Oh well.

-rb

[Mick Bailey]

The original Mosrite Vibramute used the staggered hole pattern - maybe the patent could give an explanation.