WhooHoo new M-6 just arrived.
Little confused on the Bass Knob though....
The manual states the Bass control is 'active' and has a cut/boost center 'Q' , but the pot/control does not have a detent like it sounds as though it should. They directly compare the Treble knob which does have the detent. You can feel the little detent at 12:00. Not so with the Bass knob which just goes from left to right smoothly.
Curiously the Mid knob is 'passive' but also has the detent.
The Bass knob does pull-out as stated in the manual, just thought it would have a detent to cut/boost.
Mesa is closed on Friday so I can't call the Tech today.
edit-I: I did pm Vic who has had some time with a Fathom/M6 and he is pretty sure this is how they all are.
Mesa Manuals have alway left me confused on at least one or two operational items. Shrug.
edit-II: Mark at Bass Club Chicago verified that the other M6 in stock works the same as I've described above.