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View Full Version : Bridge Misplacement on old Gibsons



Gary Hedrick
Dec-07-2012, 9:12am
I have seen a number of the teens and early 20's mandolins that have the bridges too far forward thus creating problems. My 21 F4 was a good bridge width too far forward. I kept hearing the notes being sharp far down the neck and when I put a tuner on the open and then the 12th fret I was sharp at the 12th by a fair amount.

Steve Ostrander
Dec-07-2012, 9:36am
Over years of tuning the bridge tends to creep forward if nothing is done to reset it. Or the PO may have restrung and gotten the bridge to far forward.

Jim Garber
Dec-07-2012, 10:03am
Solution: move the bridge back so the 12th string harmonic and fretted note are the same.

Gary Hedrick
Dec-07-2012, 11:22am
Oh that's what I did Jim.....took my tuner and moved it until they were spot on.....and luckily the frets down the neck are correctly spaced....

Just wanted to bring this one up (which there are other threads from the past on this) so that a new person buying their first old Gibson wouldn't freak out over this....

Jim Garber
Dec-07-2012, 11:33am
Oh, I get it. There are some Gibsons, around Loar era, where the upper frets are actually misplaced and will not play in tune. As noted, bridges do move esp for 90+ years of playing and changing strings.

Willie Poole
Dec-07-2012, 12:22pm
I have also found, and others have commented on it also, that the bridge placement marks that have been left on older mandolins show the bridges were placed closer to the fret board, some say it is due to string gauges changing...I had a 1919 mandolin that was way off using modern strings and it always looked like I had placed the bridge in the wrong place but it intonated correctly after I movd it back some so thats where I left it, BTW those marks cannot be removed in most cases....

Willie

Gary Hedrick
Dec-07-2012, 12:33pm
Oh I forgot one other thing......I was playing it out last Saturday night (a bluegrass show) and the top G string would pop out of the groove in the bridge.....so I also found that the bridge had been reversed .....sounded great before.....sounds even better now....sheesh I am going to have to pay more attention to these things because I've had the instrument for several months just haven't played in a intense setting.

side note: I am going back to my roots (50 years ago!!!) by playing an F4 on bluegrass.......back to the future....so to speak

emurray
Dec-07-2012, 3:25pm
I always took those bridge placement changes to be a result of the changes in the instrument over the years, pushed here, pulled there. I don't mean a badly sunken top just some overall shape shifting.

E

mandroid
Dec-07-2012, 3:32pm
Hey, I'm getting Up there in years, I Misplace things all the time..

allenhopkins
Dec-07-2012, 5:40pm
..I don't mean a badly sunken top just some overall shape shifting.

If there are shape-shifter mandolins I want one that can impersonate a Lloyd Loar F-5.

Gary Hedrick
Dec-08-2012, 8:52am
The curious thing about the bridge placement is that the finish is not marred "behind" the first case bridge position. Thus if it moved during its lifetime to this new incorrect position it must have done it early in the instruments life. Time, pressure and warmth do the finish impression of the bridge foot work. I tend to think that during an instruments early life either at the factory or during transit that the string tension was lessened and the bridge shifted and no one noticed when they tuned it back up.

Maybe not....but it sure seems to happen a fair amount of the time....

Jim
Dec-09-2012, 1:47am
There are alot of people that own these things, that have no idea whether they are intonated or not and really don't play them. Those that end up in the attic or back of a closet didn't get there because they were loved and played daily.

Michael Richmond
Dec-09-2012, 2:29am
Given the age of the older Gibsons being discussed, don't forget that an A has not always been the note we know it today. A as 440Hz was only informally standardized in America in 1926. And formally standardized in 1936. Prior to that there was some variation with some consensus at 435Hz due to an Austrian government recommendation in 1885.

Is it possible that the bridge placement slightly closer to the fretboard is related to the instruments being played before A was standardized to 440Hz? Maybe the bridge intonates correctly in the original position for an A that is tuned to 435Hz. Or even slightly higher at 442Hz or 443Hz.

Hendrik Ahrend
Dec-09-2012, 5:47am
Given the age of the older Gibsons being discussed, don't forget that an A has not always been the note we know it today. A as 440Hz was only informally standardized in America in 1926. And formally standardized in 1936. Prior to that there was some variation with some consensus at 435Hz due to an Austrian government recommendation in 1885.

Is it possible that the bridge placement slightly closer to the fretboard is related to the instruments being played before A was standardized to 440Hz? Maybe the bridge intonates correctly in the original position for an A that is tuned to 435Hz. Or even slightly higher at 442Hz or 443Hz.

In this context, I find it interesting that the 1923 Gibson Manual (see Mandolin Archive) states that Gibson instruments are to be tuned to "international standard pitch", that is, way before the 1936 London conference.
Theoretically, a lower tuning may affect the bridge position a bit. However, a higher action has more effect and demands the bridge further to the tailpiece. Also, it's quite possible that the instrument gives in a little over time due to string tension, which might eventually "shorten" the mandolin.
Henry

Jim
Dec-09-2012, 9:48am
Of course until 30 years ago most of these instruments were being tuned by ear and not everybody is capable of setting up accurate intonation that way.

FL Dawg
Dec-09-2012, 10:29am
All that plus the instrument's shape changes somewhat over time with string tension.

Dobe
Dec-11-2012, 6:42pm
by playing an F4 on bluegrass.......back to the future....so to speak

My first F mando was a teens 4 & it played plenty of bluegrass. Jimmy Martin wouldn't have had a problem with it, so neither did I .

Gary Hedrick
Dec-12-2012, 6:30pm
As did I......that was my "treasure" from the time Bill Monroe delivered to my father's shop until I got "smart" (you can't tell a college student anything) and bought an F12 and put the 4 in the closet.....

greg_tsam
Dec-12-2012, 6:47pm
Over years of tuning the bridge tends to creep forward if nothing is done to reset it. Or the PO may have restrung and gotten the bridge to far forward.

PO = Postus Originalis

Jack Roberts
Dec-14-2012, 4:03pm
All of my three teens (A-1, F-4, and H1) all needed to have the bridge repositioned and angled properly. Any playing higher on the frets needs it. After sitting in the wrong place for almost 100 years it leaves a mark, though...