Octave pedal is a simple pedal, it typically outputs the note you are playing one octave lower. On guitar this gives you the same frequencies as bass does and with bass you go down to the basement as to speak. Boss OC-3 features this basic mode of operation plus couple of extra things. First of all you have a possibility add another octave doubling, two octaves below the original. Also you have a mild overdrive option built-in and a polyphonic mode which is supposed to create octave effect for chords or multiple notes. In my experiences polyphonic mode is not very usable, it does manage to double up multiple notes pretty good but the sound gets very muddy. Also the overdrive option is not usable if you are already having distorted sound. It could be maybe more usable when using this with bass. But this pedal does the basic octave-effect very good and there is practically no delay in the sound. Also the second octave feature works fine, if you are into that sort of thing. Drive option could be better, I haven´t really managed to get a good octafuzz sound straight from the box.
Build like a Boss – pedal. Good quality metal case, I can´t see this breaking from anything else than a electronic failure.
My favorite settings:
Direct level: max
Oct1 level: 12 o´clock
Oct2 level: 12 o´clock
Mode: Oct 2