A while ago I had the chance to play through an Ashdown MAG II EVO-300 and I was blown away by the built-in subharmonic generator - that thing eats time and space for breakfast.
So, what kind of DIY pedal comes close to that sound? I've been looking far and wide for schematics, but rare few list whether an octaver is a harmonic or subharmonic generator, and I feel like building my own for 30$ or such.