greven voicing article

[mike-p]

Thought these might add a little to the debate . 1937 in relatively good condition, replaced sound hole braces, all else original. Sound is excellent,warm and round in the bass, not super dry like a lot I've played. These pics don't tell you much about the original shape of the guitar but do show is current state.

[mike-p]

Top pics

[mike-p]

more top and back

[mike-p]

I've been thinking over this alot and have had a thought (yes a whole one) and a question.

What does John mean by 'softer top' does he mean less stiff or a softer species ie. sitka over red spruce? If that is so what are your thoughts on this? Mostly discussed are stiffness and density not softness.

Regarding top arching on l-00's I remember as I followed the grellier plan which so far has seemed to be very accurate, once the braces were radiused to 28 foot as per the plan, the height of the braces needed no more correction. Ie they were simply straight sticks and the tapering in height was simple due to the radius on the braces. Seems to me quite a coincidence which inclines me to think that the top radius at the factory was 28 foot. I haven't taken measurements from mine but I will attempt to do so to verify the heights.

[ken cierp]

There is point in all of life where we tend to believe in the reality "we make for ourselves" -- guitar construction is no exception. If the project ends up pleasing to the maker's or customer's ear -- and one believes in the personal road map that got them there, than "bingo" all is good.

The dome dimension indicated on the "Char" reconstruction project drawing GAL 1937 L00 is 3/16" widthwise for both the soundboard and back. But the drawing itself indicates straight bracing -- again what it was originally and where it is now could be different. Disclosure of Gibson factory drawing would be very cool indeed.

I think John is comfortable with the fact that he can tune his instruments to the tonal color his customer's want and expect. I get it, and can see that the brace radius is not necessarily a key factor in his methodology or procedures. To me he has established a base line (very good concept) so various deviations are predictable relative to acoustic output.

Stiffness is a reference to cross grain flexibility of any species. Yellow Cedar for example can be very stiff cross but the surface rather soft and easily dented.

[Trevor Gore]

(Quoting John Greven)... I use the same arching on the L-00's as I do for Martins, about 52' which translates into about 1/8 inch gap at the ends of the X if you put the 17 inch brace down on a flat surface.

1/8" gap at the ends of a 17" brace works out to about 24 feet radius, not 52 feet.

http://liutaiomottola.com/formulae/sag.htm

[ken cierp]

Good catch -- likely a typo, should be about 1/16" to yield a 52' radius on a 17" cord