Common Problems

Following is a list of commonly found autoharp problems and their solutions. If you do not feel capable of doing any of these repairs successfully, the Elderly Instruments repair staff will be happy to do them for you.

Pulling Anchor Bars

In ``B''-style autoharps, the strings are anchored to a specially shaped aluminum anchor bar, which is held in place in its channel by friction and the direction of the pull of the strings. There is a great deal of stress especially on the wood of the forward edge of the channel, and occasionally this wood will start to give way under the pressure, especially if for any reason the anchor bar is not perfectly seated in the channel. Once the wood starts to give way, the anchor bar itself will begin to slide upwards and forwards, following the pull of the strings, and will become warped as it follows the strings around the crushed (now rounded) edge of its channel. The instrument owner usually is not aware of this happening, and will bring the instrument because it has become hard to keep in tune.

The solution to the problem consists of the following steps.

1. Remove the chord bar assembly and set it aside. Also remove the cover plate from the back side of the channel. The strings must be removed from the anchor bar and the anchor bar removed. (If you do not wish to change the strings at this time, you can tie or tape them out of the way.)

2. The damaged wood in front of the channel must be removed and replaced with a new piece made of a hardwood such as maple. Use a router to make a clean cavity and make the insert to fit it. Glue the insert in place with a good quality glue.

3. The old anchor bar is usually unuseable, having been warped by the pull of the strings around the damaged edge of the channel by the time the problem was noticed. Insert a new anchor bar securely in the channel. We generally anchor the bar to the underlying wood with three or four screws, for which you would need to select appropriate wood screws and pre-drill the requisite holes. (Theoretically this step should not be necessary, since the new hardwood edging strip is stronger than the original edge of the channel.)

4. Now you can either re-anchor the original strings or re-string the instrument, and replace the cover plate and the chord bar assembly.

Loose Tuning Pins

The tuning pins generally remain useably tight for an amazing length of time, considering the stress they are under, but one does occasionally find pins that have become too loose to use. Of the possible solutions, the best is not really available. Piano tuners will sometimes replace loose pins with pins of a slightly larger size, but as far as we know, the zither pins used on autoharps are only available in one size. So one is left with the following choices:

1. Withdraw all the pins in the vicinity so that you can plug the hole and redrill it to the correct size. Be aware that the usual tendency when plugging holes, of using a dowel whose grain runs along its length, will result in an easily crushed wall. The plug should be specially cut from a dense wood such as maple or beech in such a way that the grain is running in the direction of the length of the instrument when the plug is glued into place.

2. Withdraw the pin and try a wood swelling product which is made for chair repair and available in hardware stores under various fairly obvious names.

3. Withdraw the pin and shim it with an appropriate thickness of card stock or thinned-down wood veneer.

   This last choice is usually best because it is the simplest to implement and will give a result as good as any other.

Sticking Buttons

on a 21-bar chord bar set are a common problem which is easily fixed. It is not likely to be prevented by the manufacturer, though, because that would require an expensive redesign of the process by which they are made.

If you carefully remove the cover from the bars, you will find that the bars are made from aluminum ``U''-channel material, and the buttons are made in two parts: the head or actual button part and a tab to which it is glued, which fits into the slot of the ``U''-channel chord bar. Because they are loose in the bars, it is quite possible and not infrequently happens that two adjacent buttons will become positioned such that the head of one will rest on the tab of its neighbor, with the result that you have two chord bars pressed down to the strings together instead of just the one you intend to press. The solution is simply to take each button out in turn and, using a sharp knife with a triangular blade, cut the corners of the tab portion to a 45 degree angle, so that an adjacent button head cannot catch on it, but will simply slide off instead.

USE CAUTION! When cutting hard plastic, it is easy to have a knife blade slip. Make sure that the blade is sharp and that you are holding both the knife and the piece in such a way that if it slips you cannot hurt yourself.

Ends of Chord Bars Sticking

can have various causes, including:

• On a 15-bar chord bar unit, some of the glue that holds the felt to the bar may, over time, rub off onto the inside surface of the channel that the end of the bar slides up and down in, with the result that the channel wall becomes gummy and the bar prone to sticking. This is easily cleaned with naphtha on a cotton swab or rolled up end of a piece of paper towel.

• Because of irregular quality control in a newer instrument or recently installed replacement chord bar kit, the bars are not always of exactly the same length, which sometimes results in some bars sticking while others slide properly in their slots. A similiar problem can arise on an older instrument due to shrinkage of parts over time.

  To correct this, one must use a file to trim the ends of the bars that are too long to fit. Note that when the 15-chord bars are made properly, the felts overhang the ends of the bar very slightly, providing a buffer against the bar hanging on the wall of the slot. When inspecting and modifying the bar ends, be aware that the correct configuration includes this slight overhang of the felt.

• On 21-bar chord bar sets, because the bars hang near the top of their guide posts while the cover is off, it is easy for one or more of them to fall out of position unnoticed while the cover is being put on.

  It is also possible, because the edges of the guide post slot are usually not smoothed, for these edges to hang on the post, causing the bar to stick. This problem is easily cured by slightly rounding and smoothing the edges with either sandpaper or a file.

  When your 21-bar chord bars stick, simply remove the cover and inspect the ends of the bars to discover the problem. If it is not one of the two mentioned above, it will probably be a similiarly easily corrected problem. Simply correct the problem and replace the cover.

Causes of Buzzes and Unwanted Sounds

Buzzes in autoharps can have many causes. Knowing the most common causes, with a little care you can usually discover the problem and in most cases correct it without too much difficulty.

Common causes of noise on the autoharp include:

Bridge pins

On a 21-bar autoharp, the strings pass from the tuning pins over individual bridge pins which each have a guide groove to govern the string height. Occasionally the strings will buzz in sides of this groove. Often the only correction necessary is to reseat the string by forcing it upward and downward a little against the pin. Sometimes the shape of the slot needs to be opened out from a "U" type of shape towards more of a "V" shape with a file. This problem used to be more common, but the manufacturer has corrected it since we brought it to their attention and we haven't seen it as frequently recently.

On a 15-bar autoharp the bridge arrangement is different, and at first glance would not be conducive to buzzes, but we have noticed that occasionally the string will rest a little high against the guide pin sufficiently snugly that it does not rest tightly against the bridge rail itself. If you find a string buzzing, first try pushing it firmly down against the bridge rail at the guide pin. Usually this will cure it.

Bad strings

Sometimes the strings themselves are the cause of buzzes, especially at the ends of the winding on wound strings. If this is the case, a single drop of superglue on the ends of the winding will sometimes cure the buzz. Otherwise the only solution is to replace the string.

Uneven Felts

will cause some of the strings not to be adequately damped. In this case you will hear extra strings vibrating in a chord, usually somewhat muffled, but still present enough to be annoying.

Once you have determined that the problem is due to uneven felts and not to harmonic locations (see the next item), the solution is to remove the offending bar(s) and level the felts. To do this you need a long, flat piece of sandpaper. A belt sander works nicely for this if you happen to have one (it works best with the machine turned off and doing the sanding manually). Otherwise you can either get sandpaper with a sticky back or otherwise glue or double-stick sandpaper to a flat surface. If you're going out and getting paper for this purpose, I would reccomend 80 grit, but you can use coarser or finer grit paper according to what you have available. Holding the bar over the sandpaper, simply sand the felts until all the surfaces are even.

Harmonics

: Because of the general design of the autoharp there is no way to avoid some of the bars falling at node points of some of the strings. The symptom that results is that harmonic overtones of these strings will sound (rather than the natural note of the full length of the string) along with the desired notes of the chord if the bar is pressed lightly. The only solution to this problem is to be sure you press the bar firmly, and perhaps modify your pick attack on the strings so as to less easily move those strings that are not completly free of damping from the felts.

If the felts are uneven (see the preceeding item), they will tend to exaggerate harmonic problems. Correcting the uneven frets will help even though it will not eliminate harmonics.

Anchor Cover Plates

on ``B''-style instruments will sometimes buzz if they don't happen to lie snugly against the body. Often people will tuck a pick or piece of card stock under the loose portion of the plate, and this is really both the simplest and most effective way of dealing with this type of buzz.

Hopefully you will find the cause and cure of your unwanted noise in the above list. Otherwise all you can do is check the instrument over carefully until you can discover its cause.

Arnold M.J. Hennig
Elderly Instruments Repair Dept.
April, 2003