I'll confirm the Digitech BassSynthWah, to my surprise. I've tried a few (lesser expensive) pedals looking for an octaver with acceptable tracking and have been rather disappointed. I've owned a Boss ME-50B, Zoom B2.1u, Zoom B3, and found the octave functions in each to be unusable due to poor tracking and/or tone. At the music store I've tried the Boss and MXR Octave pedals and was also disappointed. Unless I'm doing something wrong (not), I don't quite understand how they are so popular. The Pog2 was better but couldn't justify the price. Anyway, I recently bought a $40 Digitech BassSynthWah on Ebay for laughs and bingo! it does what it's supposed to do. Actually, 90% of it is unusable cartoon sound effects, but set to the simple octave function, it puts out a smooth-sounding, stable-tracking octave.