http://www.ProGuitarShop.com -This is the Fulltone OCD version 4. The Obsessive Compulsive Drive pedal is the perfect mate for a great tube amp. If you're lucky enough to own a Vox AC15 or a Marshall JTM45 and have a place where you can turn it up all the way, then you have an idea of what the Fulltone OCD is capable of. Plug in the OCD pedal, lay into a bar chord, and you will hear multiple layers of rich harmonic overtones in addition to the fundamental tone. This is not a subtle effect, these are beautiful ringing feedback tones that can be easily discerned and even sung if you have good ears! The Full Tone OCD produces classic tones you've heard on records by Led Zeppelin, The Beatles, Hendrix, AC/DC and others. Roll back your guitar's volume knob and you'll have access to a whole myriad of gorgeous tones, including shimmering, spanking, full range clean sounds. The OCD pedal allows your guitar's natural tones to bloom, so your Strat will still sound like a Strat, and your vintage Les Paul will still sound like a vintage Les Paul. Overdrive and distortion pedals have always been something of a compromise in comparison to a great guitar amp cranked to the "sweet spot". Feel, tone, and harmonics often fall by the wayside when an overdrive pedal is plugged into the front end of a great amp, until now. Check out a Fulltone OCD at Proguitarshop.com and see what a great overdrive pedal can be!