From Jumping Flea - great site to check out!
Strings are ornery topics for most uke players. You can start an argument (or to be civilized, a heated debate) among uke players by simply asking what strings they prefer. Uke players will also argue over the quality of various tonewoods, but perhaps not quite as readily.
Strings are also very personal and affect a player's style and expression. Brand loyalties rear their heads in discussion, too. Since no two wooden musical instruments are ever exactly alike, what sounds good on one may not on another, even another of the same brand and model.
Strings used to be made from gut, but now are made out of nylon (i.e. GHS, Ko'olau), nylgut (i.e. Aquila) or fluorocarbon (i.e. Worth). Each material has its own tonal qualities.
The low-G strings are usually wound (nylon wrapped in a metal - aluminum or silver - sheath, although Kala Reds are apparently nylon wound). Some manufacturers are also using a wound C and there are sets with both the G and C wound.
These wound strings produce a more mellow, mid-to-bass-oriented tone. However, wound strings can be harder on the fretboard and will wear down the plastic frets of some ukes (i.e. the Fluke).
Most ukulele strings are not steel, like a guitar. Putting metal guitar, banjo or mandolin strings on your ukulele adds a lot more tension and stress on the bridge. It could rip the bridge right off! At the very least it will warp the top and possibly the neck. However, there are some ukes designed for steel strings- especially the solid-body electric ukes like Risa and Jupiter Creek.
In general, thicker strings have more tension, so they are louder, but can be a little more difficult to play and don't bend as easily as thinner strings (for new players, thicker strings can be more painful until the callouses grow in). Tenor strings have more tension than convert, which has more than soprano strings. Extra tension also improves volume.
Thinner strings are more flexible, but not as loud and sometimes prone to buzz on a uke with low action. Personally, I prefer a slightly heavier string for more projection and volume.
Long-necked ukes like the Ohana (tenor neck on a soprano body) need thinner strings for the lower tension to help prevent neck warping.
For resonator ukes, you may want thicker strings with more tension to transmit the most sound to the cone. My Republic came with thin GHS strings, which are probably fine on a wooden uke, but not the best choice for a reso. I changed them to heavier Aquilas and got a better, cleaner sound.
Overall, I prefer Aquilas for most ukes because of their volume and brightness, but again it really depends on the instrument and your own personal taste. I have also enjoyed D'Addario J71s (Pro Arte) on several ukes and while more mellow than Aquilas, they have a smooth texture that makes them easy to play. Worths are also good and have their loyal users.
In my own experience, all of the black strings I've tried have been too soft and too mellow for my taste, and I've replaced them with something else. That may not be true of the new Blackline strings, but I have yet to try them.
You can get an endless supply of opinions on string brands online, but be prepared to wade through many arguments over which is best. Since strings are relatively inexpensive, it's not a big investment to try a set for yourself. In fact, when you buy a uke it's a good idea to order a second set of strings right away.
Nylon or fluorocarbon strings - and the Pahoehoe strings for the U-bass - take a while to stretch before they hold their pitch. How long depends on the type of string, the type of tuners you have and how much you play. It can be a day or two, it can be a week or more. be patient and keep tuning as you practice.
Geared tuners are more likely to stay tight - therefore in tune - than friction tuners. You can tighten friction tuners by turning the screw on the head, but you can only tighten them so much or else you won't be able to move them at all (or risk stripping the threads!).
I prefer geared tuners because they're easier to use, faster to wind strings and simply more efficient and modern. The only friction tuners I've ever rally been satisfied with are on my Fluke. Friction tuners just seem so 20th century... ;-)
Soprano and concert strings are usually the same diameter, concert strings sometimes being a bit longer to allow for the greater scale length. Tenor strings are a bit thicker to handle the greater tension on the strings, and baritone strings longer and thicker than the rest (you can use guitar strings for a baritone).
Diameters vary with manufacturers. For soprano and concert strings I have seen a ranges of:
Check the sizes on the packages your favourite guitar strings. You can generally use those thicknesses as a rule of thumb for replacements, but keep in mind that nylon strings are generally a bit thicker than the same string in fluorocarbon. From Curt Sheller comes this rule of thumb for replacing uke strings with guitar strings:
You can use guitar strings for ukuleles, if you have the right string gauge. Some more inventive players even use fluorocarbon fishing line (check the forums for threads on this subject: here and here) because it can be bought in bulk at a better price.
That would be for a high-G tuning. I used a set of standard Fender Bullet strings with .010 (A), .013 (E), .017 (C) and .026(G) gauge for a low-G tuning on mine. These are a bit thinner than what Elderly uses, but give a little more flex.
Here's an interesting page of data on the various Worth strings. They offer several unusual options in their sets, including light, medium and "strong" sets, as well as some options for the low-G string: fat, hard and heavy, but there is no explanatio as to what these descriptions mean.
Nylon-string ukuleles put less pressure on the bridge and top than guitars, even nylon stringed guitars. Larger ukes have more tension. According to Kawika, Inc. these are the approximate tensions on the various sizes ukes:
In comparison, a classical guitar has 75-90 lbs. of tension and a steel-string guitar has 150-200 lbs. tension. If you put steel strings on a ukulele, you're likely to pull the bridge right off because it's not designed for the extra tension.
A concert would likely be around 35-36 lbs.
I've read that many classical guitarists string their instruments with a glass or metal bead at the bridge rather than tying the string to the bridge. This apparently improves the treble end of the tone.
There's some discussion of this technique by Peter Kun Frary, Professor of Music at the University of Hawaii and other sites. What works for guitars should therefore work for ukuleles.
I found a few different types of beads to try at a local craft shop (glass and metal) and attached them to some of my ukes to see if there was any noticeable change in tone or frequency response. Overall, I didn't notice a lot with an unplugged uke. There may be a bit of improvement with an amplified uke (but it may simply be wishful thinking).
There's a photo on the left of how the beads look at the bridge. I chose some anodized glass beads for a bit of extra colour. I think it's attractive without being gaudy.
I thought the traditional method of tying the string looped through the hole and back over the bridge might contribute to dampening the bridge's vibrations, and further mute the waves going to the top. I don't think it would be a significant loss, but a bead would help alleviate that effect.
Make sure you trim the string end after they're settled and tight. If you do it too soon, the string can end up pulling itself through the bead as you tighten the string. If you leave it too long, it can contact the sound board and buzz.
An alternative to the loop tie is to push the strings through the bridge hole, then knot them, as shown here for classical guitars. Again, watch the string ends because they can buzz if they vibrate against the top.
Also keep in mind your saddle is critical to the sound. Wooden saddles can be replaced with natural bone, or an artificial material like Tusq, Nubone and Corian. I've found Tusq saddles really brighten a mellow uke. See my section on saddles for more.
Another hotly debated issue on the forums. I prefer to play with my hands most of the time - using my fingertips, nails, edges of my hand and thumb. As a musical tool, your hand can be incredibly expressive and subtle. Most players play and strum with their hands and fingers. Some grow their fingernails for use.
Picks are not generally used by ukulele players, but there's no reason you can't use one aside from tradition. In fact, I recommend you explore using picks to discover the range of sounds and styles they allow.
There is a fat, soft felt pick sometimes sold as a ukulele pick (or properly: plectum) or included in a case when you buy the instrument. It's been used for many, many decades, I find it too muted, too chunky and too clumsy. It's really for strumming, not picking. Some folks seem to like it, but I find it awkward.
I have used guitar picks, especially with the eight-sting Lanikai, my Risa, Eleuke and when trying some slide uke on the resonator. A pick is certainly a good tool with the steel-stringed electric ukes or when playing amplified.
Picks make notes louder and brighter, but also sometimes harsher. A pick has a sharp attack and can really make notes stand out. There are times when playing with a pick is the only way I can get a specific sound, especially when running through an amp and an effects box.
I prefer thin, flexible picks to rigid/thick ones, but that's a matter of taste. Softer picks can give more leeway when strumming and seem easier on the nylon strings. You can even made quite serviceable picks from soft plastic containers like margarine tubs.
Some people also grow their fingernails or use plastic fingerpicks when playing, but I don't find them necessary and can make the uke sound quite different from using just your fingertips, often too brash. I prefer just my fingers and don't have to worry about breaking a nail - and I can produce quite a range of sounds with my hands alone.