The tone button contains a one-knob "all-or-nothing" equalizer, compressor/gate and de-esser. The equalizer throws away all of the warmth for male voices (and I guess the same is true for altos). I contacted TC Helicon and they responded: "It's an all or nothing. Sorry you don't like it."
next to that, the phantom power button sometimes refuses to switch but the rest of the functionality is pretty nice.
Altogether, I wouldn't recommend it to anyone. If TC Helicon would have responded earlier to my question, I would have returned it.