Do you need to play in several tunings but don't want to constantly change strings each time? Or, you don't want or can't afford to have one guitar for each tuning? Meet the Digitech Drop. It down tunes your guitar in half steps until one octave. It can also work as a simple octaver, as it is also capable of mixing your dry signal with an octave down signal (50/50 mix). You can press the button one time to activate the pedal, and another to deactivate, or keep the foot on the button to activate the effect and just release it to turn it off (functions selectable by a toggle switch). You can select your tuning with a knob. Simple enough. Just put it right after your guitar in the signal chain. But what about the sound? These technologies are not perfect, but they're almost perfect, and if you know their limitations, you'll be perfectly happy with the results. The first thing I noticed when the pedal is active is that the signal volume is a little bit reduced. So, hitting the front of your amp, in a clean channel you'll feel you have a little less volume and in a dirty channel you'll feel that you have a little less gain. Some people say that the pedal cuts a little bit of the highs. That's not true. What happens is that, on full chords, while analyzing the frequencies in your signal, as it is working its magic, it kinda emphasizes lower frequencies. It's kinda like you loose a bit of the sustain on higher frequencies when playing full chords. As you do a full chord, you'll hear all the strings, but the thin ones will stop ringing sooner, but if you ring the thinner strings again, you'll hear them loud and clear and they'll sustain normally. Your results might vary with different pickups. One thing I noticed that seems to help is increasing the volume of the signal going into the pedal (as if you are compensating for the loss of output from the pedal). I also have a discontinued Morpheus Droptune that essentially does the same thing, but the Morpheus is more than twice the size. As it is getting older, it's doing a little bit of noise sometimes, so I bought the Digitech one just in case. I've been using this technology for some years now and it suits my needs perfectly, practicing at home, at rehearsals and live. Another limitation that this technology has: if you select very low tunings on the pedal, you might start to hear some artifacts. This is why I have just a few guitars in different base tunings and use the pedal to lower them up to 3 half steps (1.5 full steps). People say the limit is about 2.5 full steps (5 half steps) and after that you get artifacts. I can't confirm or deny (as I only go down 3 half steps) but here's the information anyway just in case. With all these cons I think I might be making it sound worse than it actually is. This pedal works great. It just has some limitations in some very specific situations and you can work around them. If you have doubts about buying it, don't! There's a reason this pedal is constantly out of stock everywhere. Yes, supply is not the best right now, but when they're in stock, they seem to sell right away, and that happens for a reason: this pedal is that good!