overtones
Posted: 14 Apr 2012 8:08 am
Chuck, you have had a lot of good suggestions but there's one I don't think I have seen yet.
It appears that you purchased the guitar second hand and it also looks like you have narrowed the overtones to the bridge end of the guitar. In other words one of the suggestions that was given to you was to put more pressure on the bar and to dampen the strings behind the bar with your fingers. If you did this and you still have the overtones it seems like they would have to be coming from the roller or string finger to which you attach your string. There's a couple of things that could be going on here.
1) The prior owner may have dressed the bridge roller and caused a flat spot on top of it. Doesn't have to be much and it doesn't take much sanding to get a flat spot on the top, especially if the finger is made from aluminum like most guitars. I've never been around a GFI so I'm not familiar with how they are manufactured or designed.
2) If the string hooks to the bridge roller by a pin in the back, the pin may be bent up just enough to let the wrapping around the brass eye end hit at the back side of "dead center" on the bridge roller not letting the string seat on top of the roller properly and causing a buzz or overtone. This is highly unlikely but it's something to check. I've seen people pull their hair out looking for string buzz.
You can check for #1 by drilling a hole in a piece of wood or a piece of 1/8" thick aluminum flat bar. The hole size would have to be a size that is equal to the radius on the bridge. I don't know what size that would be. I build mine out of 3/4 aluminum because I want a 3/8" radius on my bridge. Yours would probably take a 7/8" drill or maybe a 1". Then you cut the bottom of the hole off just above center. Take some machinist lay out dye and coat the top of the roller bridge. You can then take the radius pattern that you made, carefully place it over the bridge and slide it across and back from the 1st to the 10th string a couple of time. If the roller is flat it will leave the dye on the flat spot and I'll tell you where to go from there. I'll watch you post to see any reply's. Just pray the roller isn't flat, that could cause a lot of work if you don't have enough room to sand the roller back to round with it still in the guitar.
Winston
It appears that you purchased the guitar second hand and it also looks like you have narrowed the overtones to the bridge end of the guitar. In other words one of the suggestions that was given to you was to put more pressure on the bar and to dampen the strings behind the bar with your fingers. If you did this and you still have the overtones it seems like they would have to be coming from the roller or string finger to which you attach your string. There's a couple of things that could be going on here.
1) The prior owner may have dressed the bridge roller and caused a flat spot on top of it. Doesn't have to be much and it doesn't take much sanding to get a flat spot on the top, especially if the finger is made from aluminum like most guitars. I've never been around a GFI so I'm not familiar with how they are manufactured or designed.
2) If the string hooks to the bridge roller by a pin in the back, the pin may be bent up just enough to let the wrapping around the brass eye end hit at the back side of "dead center" on the bridge roller not letting the string seat on top of the roller properly and causing a buzz or overtone. This is highly unlikely but it's something to check. I've seen people pull their hair out looking for string buzz.
You can check for #1 by drilling a hole in a piece of wood or a piece of 1/8" thick aluminum flat bar. The hole size would have to be a size that is equal to the radius on the bridge. I don't know what size that would be. I build mine out of 3/4 aluminum because I want a 3/8" radius on my bridge. Yours would probably take a 7/8" drill or maybe a 1". Then you cut the bottom of the hole off just above center. Take some machinist lay out dye and coat the top of the roller bridge. You can then take the radius pattern that you made, carefully place it over the bridge and slide it across and back from the 1st to the 10th string a couple of time. If the roller is flat it will leave the dye on the flat spot and I'll tell you where to go from there. I'll watch you post to see any reply's. Just pray the roller isn't flat, that could cause a lot of work if you don't have enough room to sand the roller back to round with it still in the guitar.
Winston
I agree with Steve English. I think this his what he is suggesting. I noticed the problem because I chime off other strings to tune (don't want to get anything started 
) and got extra beats till I put this small piece of foam between 5&6. Don't know why but this fixed the overtones or unwanted beats.