The M1 Active features built-in all class A electronics, so there's no need for any external preamps and it's compatible with any outboard equipment. The new volume control gives you fingertip access in any performing situation.
The M1 is a humbucking pickup with a twist. In a common stacked humbucker, the second, lower coil cancels hum, but doesn't contribute anything positive to the sound. In fact, it can muddy the sound of the main coil. The M1 unlocks the second coil. This allows it to make a positive sonic contribution while maintaining the pure open sound of a single coil--but without the hum.
TriAxial Dynamic Technology The hum-canceling coil is suspended under the main coil by a tuned support that allows it to move in 3 dimensions. The primary coil moves with the guitar top and creates a body signal in the suspended secondary coil. This brings the M1 to life, with string and body sound all in one. It's like having a dual pickup system in your soundhole. And it's all passive! The support is carefully tuned to control motion in all 3 dimensions. This allows you to selectively add the presence and realism from the body signal while suppressing runaway feedback.