Strings going flat

[Jasper]

Recently noted that when I am chopping pretty hard on my mando, but only muting the strings, not actually playing the chord, my A strings, and only my A strings, are going flat. So I figured it was the original equipment cheap tuners...I replaced them with Grovers...same problem.

Any ideas? The bridge isn't moving and the tail piece isn't coming loose either.

Jasper

[Bill Snyder]

Could be the A string binding in the nut when you tune up. As you play it releases and goes flat.

[Rroyd]

Do they eventually quit going flat over a period of time, and then stay in tune? If that is the case, there are several things that could be happening. My first thought is the slots in the nut are too narrow, which can cause a string to bind enough to be in tune until picked vigorously, and then slip a little and go flat. Since just the two A strings are involved, that would a good place to look, as the "A" slots might be narrow. There are a couple of other things to consider, but since you are having the problem with only the two A strings, they are far less likely. How many wraps do you put on the tuning peg shafts? I've seen strings slip when there was only one or two wraps around the shaft, especially with smaller diameter strings. I have also seen them bind and then give a little in a Gibson style tailpiece, but in both cases the tuning will stabilize after things quit giving and slipping, although I have seen the string slipping on the peg shaft last for a day or two, before it finally bound or it broke. Usually these last two problems don't happen consistently, and it's highly unlikely they would affect just the two A strings. If the strings just keep going flat and never stabilize, then something is going on that would require a mando exam. Good Luck!

[Jasper]

Rroyd,

Unfortunately, they continue to flatten, whether new strings or old. This never really corrects itself. I have had the mando for over a year, and this is a very recent aggravation. Other than this, it has been a very good mandolin. And I find it very odd that it only happens when I am chopping muted strings. If I play the chop chords, even hard, I don't have this problem. I have a Weber universal cast tail piece, so I don't think the problem is there. I will check the nut to see if there are any aberrations in that area.

Thanks,

Jasper

[Gavin Baird]

Jasper,
I have run into the same problem on a specific Mando with Waverley tuners. ie the ones with the backlash adjustment on the wrong side of the worm shaft. When you tune up to pitch any backlash is taken up towards the tuning knob. When you have the string in tune any backlash is now at the inside bearing surface. ie there may be end clearance at that point. As you play, even though it is a worm and pinion arrangement. the tension of the string is trying to rotate the shaft into a down tune position or "Flat"
Another situation is that since the string is quite heavy, large in diameter, it is very stiff and without outside windings to inhibit movement may have a tendancy to slip around the shaft if you do not have enough turns to prevent this....G

[bolannta]

This reduces string slippage at the tuner post.

http://lib1.store.vip.sc5.yahoo.com/lib/stringitup/restring01.gif

[Luthier Vandross]

I string one wrap over, two wraps under, about the distance to the next tuner shaft. It pinches, and no binding, or unwrapping of the winding, from the core. -just me- When you tune, you drop below the pitch, and tune up to perfect.. and if you overshoot, you start over.. I'm sayin'.. right?

So, if it's still going out of tune, obvious thing is that there is a small burr holding tension behind the nut, or behind the bridge. (not likely with a newer wooden bridge)

Pick angle; Are you playing across, or do you play like me, and play down toward the treble side of the top? I frequently hit them hard enough to detune, and I wear out upper frets.

I'd pick the nut having a burr.


M