Hi everybody, I'm a new ModFactor user and so far impressed with this stompbox and its sounds, but I don't quite understand the "Voc-Wah". As far as I know, it is supposed to sound "talk boxy" or "vocal", but it doesn't. No matter if I dial in "B..EA..T" or "TH..I..RD" or something like that (which is not explained in the manual), it always sounds the same.

It really doesn't get talk boxy until you dial it in to modulate b/t two different vowels.  Turn the topmost rightmost knob past the 0-100 numerical read out to the point where you see the vowels to pick the "base" or "starting" vowel.  Then use the depth knob to pick the ending vowel.  I find starting on B-EA-T and ending on R-A-W to be the most dramatic.  I also find that the BASSVOC Type actually works a little better even for guitar b/c it preserves the low end.  Pick any modulation source you want.  But my personal preference is a sine wave with fair amounts of S-MOD and D-Mod with Mod Source set to Envelope (for the secondary modulation, adjust sensitivity to taste), that way the vowel movement really responds when you dig in.