As a strings instructor(guitar/bass/ukulele/mandolin, etc...), one of the most under appreciated topics of teaching is how to properly use a tuner. Many times, a student will come in with an instrument that is so out of tune that it makes me cringe. They try to play it (out of tune) without realizing the resulting poor sound. Should the blame lie on the student at that point? Nope, it lies with the teacher for not expressing the importance of a properly tuned instrument. Everyone, even students not learning with an instructor, heed these words, learn to tune now!
First off, let's talk a bit about the types of tuners out there, how they work, and what will be the best for your specific applications. For a typical string player there will be two main types; one that is specified for your instrument, and chromatic styled tuner. Here is a big hint, always go chromatic. Let's say you buy a "guitar" tuner, the notes the tuner picks up will be limited to the open strings on your guitar (EADGBE). The tuner might have a flat or a sharp function built in to allow you to tune the whole instrument up or down a half step, but this will be limiting in the future for you. A chromatic tuner, on the other hand, will pick up and display any note that you choose to play. What if your guitar is so far out of whack that it isn't close to where it should be? You could end up tuning your instrument to a point that sounds like fingers on a chalkboard when you nail a chord.
Let's limit our talk from here on to chromatic tuners. There are three main types; a hand-held (such as the Korg CA-1(see fig c)), a pedal tuner (like the Boss TU-3 (see fig b)), or a clip-on style tuner (the Snark SN-1 (See fig a)). All have their place and depend on what you want out of them.
Fig A - Snark SN-1
For instance, a clip-on tuner can be a great thing to squirrel away in your acoustic guitar case. Now why did I say acoustic, and not electric? Well, you see, a clip-on tuner works by attaching to the headstock of your instrument, and then proceeds to feel the vibrations of the note you hit. It is then able to determine what note you are playing, and if you are sharp or flat. An acoustic naturally vibrates with more strength than an electric does. I would trust using one with an acoustic way more. I've used a number of these styles, with mixed success, on both electric and acoustic, and like I said before I like them much more for an acoustic.
Fig B - Boss TU-3
Now on to the stomp-box pedal tuners. First thing to know, out of the three styles of tuners we are talking about, this type can tend to be the more expensive. Here's the deal, if you are a gigging player and are constantly needing to tune your guitar during a set, because of those wicked bends you are doing, then this should be your choice. Anybody that has played a gig can tell you that your guitar does not stay in tune until throughout the set. To use this style of tuner, you plug your guitar into the input and then the output of the pedal will continue on to the rest of your pedals or to your amplifier. Stomp on the foot-switch, and it will usually mute your signal so you don't have to annoy the crowd while making sure your guitar sounds tasty.
Fig C - Korg CA-1
The last type of tuner is the good ole' hand held. These handy guys can be stashed in your cable bag and you will always have a way to make sure you can tune. What happens if your stomp-box tuner goes out and you don't have the time to fiddle with batteries? Grab this guy. These tuners usually come with both an instrument jack to plug your guitar in, and a small microphone to pick up the sound. I advise always using the input jack as compared to the microphone. Background noise can be a total pain when trying to tune. Especially those pesky drummers that don't get that we need them to be quiet while tuning. Anyways,... those are the three main types of tuners out there. There are other types, but not the most applicable to the average player's uses. Next time, we will get into the nitty-gritty of how to actually tune our instruments.