If you aren't used to tuning stringed instruments, getting the tuning right the first time can be difficult. Luckily, a dulcimer is one of the easiest instruments to tune since it only has four strings and 3 of those strings are tuned to A. With a little practice, stringing and tuning your dulcimer will become second nature.
Remove your old strings by either unwinding the keys completely or cutting them wire cutters. Depending on the type of bridge you have either remove the pegs at the base or untie them from the bridge. Then simply pull the remaining ends from the keys.
Start with the bass (D) string. Again, attach the string to the bridge depending on the make of your bridge. If you have pegs, place the looped end of the string into the peg and push the beg down into the bridge. If you simply have holes, tie the string to the bridge by forming a small loop and pulling the loose end through the hole. Pull it tight, making sure that none of the loop extends into the playing area.
Place the other end in the hole in the key. Your bass string will likely only go through once. Hold it tight, and begin tightening the string. Continue tightening until it can play a steady note.
Follow the same procedure for the remaining three strings. Note that you can likely loop these strings one more time through the hole in the key, which will make them more secure and prevent slippage.
How to Tune a Dulcimer
Tune your dulcimer by beginning with the bass (D) string. You can get this string to D in a number of ways. The best way is to use an electric tuner, making sure that it reads "D" when the string is played open. You can also tune it to another tuned instrument by playing a D on that instrument, such as, for example, the open 4th string of a guitar.
Tune the second string to A. Again, you can use an electric tune or another instrument (3rd string, 2nd fret on a guitar, for example). You an also tune the dulcimer to itself now. The A on the bass string is the 4th fret. Strum this and tune your 2nd string to the same note.
Tune both the third and fourth strings to A, but one octave higher than the third string. You can do this by ear or by fretting the third string on the 12th fret.
Strum the strings for a few minutes. New strings will take about an hour to hold their tuning perfectly.
To make sure both of your high A strings are tuned perfectly, play them both together. Listen for small "pulses" as the notes rings. If you can hear them, one string is slightly off from the other. Adjust the keys until the notes play together smoothly sounding like just one note.