Buzz

[TEE]

My mandolin has developed a buzz. It is primarily on the G strings. I have checked everything I know to check. It is not the nut because it does it worse when fretted. Raising the bridge does not help and there are no loose frets.I have removed the tailpiece cover and have eliminated that as the problem.

Some time back while changing strings I took the bridge off and the back of it was very rough. I sanded it smooth and put it back on. I just freehand sanded it and did not worry about matching it to the top like I should have.

My question is would a bridge that is not fitted to the top cause a buzz? Or does this sound more like loose brace?

I cant take it to luthier right now so I am looking for suggestions. I forgot to mention I did have a bridge top and I tried it but it did not help. I will get some sandpaper tommorow and sand the bridge properly but I am just wondering if that could cause the buzz. Thanks

[Rick Lindstrom]

First, check all of the hardware on the mando- tuning machines, tailpiece, tailpiece cover, and so forth. If that doesn't get it, check the truss rod and make sure it isn't LOOSE. Ignore the dire warnings you will get from others about fooling around with the truss rod because you're just going to check the tension, not adjust it. LOOSE means that when you put the wrench on it, it turns easily in both directions with very little resistance. If it is loose, turn it gently clockwise until it just snugs up a tiny bit.

I've been a little surprised during the time that I've been following these forums on the Cafe at how often a loose truss rod will be the source of buzzes or rattles on a mando, especially new ones. I think that builders probably don't put much tension in them if the neck has the proper relief in it from the start and they back out and loosen over time. Or something like that.

Of course, if your instrument doesn't have a truss rod, this advice is in vain

Also, as you surmise, it could be a loose brace, but you should check the easy stuff first.

Rick

[TEE]

Truss rods tight, all tuners and hardware seem fine. I have taken the strings off and checked everything on it. The sound seems to be coming from the soundhole or bridge area. Whats the easiest or best way to check for a loose brace? When I had the strings off I tapped around on the top but could not hear anything. I thought maybe I could hear a loose brace but I could'nt. It sounds a lot like when a tailpiece cover is touching the strings but it is not. The tailpiece also has felt under the strings also.

It is worse on the top strings-The bottom strings sound fine.

[Rick Lindstrom]

How about the thumb wheels on the bridge? Does the bridge top rest firmly on those (when strung up), or is the bridge top jammed on the post allowing the wheel to turn freely and vibrate?

Check that the underside of tailpiece isn't touching the top, and maybe put a thin scrap of felt in there to be on the safe side.

Also, depending on the type of sound hole and its location, you might be able to get a finger in there and give the braces a wiggle. The prescribed method is to use a dental mirror and flashlight to look inside, and if you have the strings off, you can pull the endpin and look into the body of the mando through the hole and see at least some of the bracing. I understand that the little mirrors are available at drugstores.

Rick

[sheppard686]

When looking at the tone bars with your mirror you may need tension on the strings. Sometimes a crack or split is hard to see without having pressure on the top to "push" possible flaws open.

[TEE]

The tailpiece is off the body and I put a piece of rubber under it just to make sure but it did not help. I put my finger in the F hole and could not move the brace and also removed the endpin but could only see the end of the brace as the endpin is installed with just a small screw.

I can not feel the whole brace with my finger as my fingers are large and I could only get my pinky in the largest hole but it did not move or anything.

I will go find a dental mirror and try it with the strings on.

Also the screws are snug on the bridge but the bridge does need to be more snug to the top as I can see just a sliver of space between the bridge and the top in a few places mainly at the treble side. I am talking about very small like razor blade spaces- I need magnifiying glasses to see that.

This is a japanese made kentucky KM850 that I have had for twenty-five years and never had a problem with before.

[Rick Lindstrom]

Looks like you've hit all the high spots. If it's not a loose brace, it'd probably be a good idea to refit the bridge if you can see light under it. Here's an article from the Frets site on doing that:

http://www.frets.com/FretsPa....et.html

Also, you might want to have a look at Frank's "Big Buzz List":

http://www.frets.com/FretsPa....ro.html

For those of us with inquiring minds, be sure to tell us what it was once you nail it.

Rick

[TEE]

Well yesterday I bought a mirror and checked the braces and they look fine. I put new strings on it and since I had to play last night I took it with me. In the middle of a song I heard a loud pop. The bridge had broke in half lengthwise. It broke from the thumbscrew on one side to about halfway across. So maybe there was a hairline crack there that was causing the buzz. I will have to try a new bridge (don't have one yet) Any recommendations ? Thanks

[sunburst]

I'd say that was the problem.
What kind of bridge is it? If it's a "standard" adjustable bridge, you can probably just get a new top (saddle) for it, rather than a whole new bridge, and save the trouble and expense of fitting a new bridge base to the top of the mando.
Check with Steve Smith.

[billhay4]

Steve is at Cumberland Acoustic in case you didn't know.
Bill

[littlebuddie]

Hi TEE,
I bet you found the answer to your 'buzz' problem alright. What ever you decide to replace with, at least salvage those old thumbwheels. I made a bridge the other day out of some old maple wind-fall I scavenged in the back yard, topped off with a little black walnut veneer I have left over from building my IV kit. I used the thumbwheels from the (nasty) bridge that came with the kit. It works well considering I never made one before. So if you ever need something to do, you can build your own.

[TEE]

Thanks-Everyone Thats a nice looking bridge, I am not sure I am that handy though.

[mandroid]

alternative upper bridge material, perhaps
Builder Kurt Gisclar in Alaska, made a very nice fossil walrus tusk upper bridge piece .

you could mail the broken one and replacement would come back identical to what was on there.



height /width/string spacing /offsets, etc.

offers capped ebony or whole thing from those old bottom feeding clam eaters tusks.