jwar wrote:I'm not even sure what zero flanging is? I'm I blissfully ignorant here?
I'm sure Jack could do a more technical explanation, but from a non-pedal-builder, here goes:
The best way to explain what through-zero means is to explain how a flanger works. Originally flanger was created by playing two copies of the same track, and slowing down the tape of one of them slightly (<10ms), and then letting it speed back up while slowing the other one down. You get a standard flanger comb-filter sound. But at the exact moment when the first one overtakes the second one, it creates this awesome unique cancellation effect.
Most pedal flangers emulate the flanger sound by delaying one line, modulating the delay time, and mixing it with the dry signal. But the delayed line can never overtake the clean one. It can't go "through zero" delay time (unless you invent a way to have negative delay time, i.e. travel into the future)
There are a few flangers out there that can go "through zero", by using TWO delays, and modulating them both so that one can overtake the other.