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MANDOLINMYSTER
Dec-20-2010, 12:37pm
Recently I made an observation that "not all Gibson A model braces are the same" I am fortunate to have several A model Gibsons from 1919 thru 1929 and the braces are all a little different. They vary in height, width and most recently discovered the width of the flat section. The one with the shortest flat section is a 1919 A3 and the beefiest brace belongs to a 1922 A2. So next time your at a gathering of ole Gibbies take a peak through the sound hole and see what I mean. I'm not sure if these braces varied by design or they just did not have a particular template to follow??

frshwtrbob
Jan-01-2011, 8:53pm
inside an A-Jr.-------practically braceless.....66711

Dobe
Jan-01-2011, 9:23pm
Just goes to show ya; Braces are mostly for tone manipulation rather than structural support !

Gail Hester
Jan-01-2011, 9:28pm
I recognize the picture since I took it. That's actually a 1920 A0 that I turned into a super paddle with repairs, the back was broken out so I made a new one, re-gduation, refinish and a logo.

barney 59
Jan-01-2011, 9:30pm
At least in the way they feel to me later model Gibsons seem to weigh less than the earlier models even with the added trussrod. I always assumed that the tops and maybe the backs were somewhat thinner in the newer(20's) models. If that is true it would also explain the reason or need for increased bracing in the 20's model mandolins. Someone is going to come up on this posting with exact figures both in measurements and specific gravity of the materials involved but the earlier models always "feel" a little clunky to me compared to the the ones produced in the 20's.

frshwtrbob
Jan-01-2011, 10:09pm
Hey Gail,
That A came out better than new. Would you be so kind as to tell me who's adjustable bridge, the kind & size fret's and the kind of nut you ended up using. I'm in need of these for my A-Jr. so a pro's choices are welcomed.
Bob G

Gail Hester
Jan-01-2011, 10:34pm
Bob, the bridge is a Cumberland Acoustics bridge from Steve Smith, I use bone nuts on the oval holes and the frets I believe were StewMac banjo wire.

The transverse braces were used on Gibson A-style mandolins to make up for the structural integrity lost by cutting out the material for the sound hole. Otherwise, no brace should be needed on an arched instrument (so I'm told). Every one I've seen from the 1900s thru the 1920s is very close to the same size with small variances due to their handmade nature.


At least in the way they feel to me later model Gibson’s seem to weigh less than the earlier models even with the added trussrod. I always assumed that the tops and maybe the backs were somewhat thinner in the newer(20's) models.

Several years ago I posted an average graduation map that I had made over the years averaging dozens of mandolins to compare pre-Loar and Loar era oval hole mandolins. The jest of all that was that while there are lots of great sounding outliers, typically the Loar era instruments had a bit thinner backs and sides with thinner re-curves and the graduation were more refined or smoother thick to thin then earlier models. Some, including myself, believe that this produced punchier/more focused mandolins while Loar was around. This is not to say that there were not a lot of great mandolins built earlier but they were generally a bit different in sound and feel.