O.D.-Zilla! This is a custom Submini Tube Overdrive made for me by Rick Holt at Frequency Central. It has separate clean/od channels and a master volume. The Marshall tonestack works on only the od channel. The clean signal comes through untouched and is boostable. The "dirt" feature adds more overdrive at the flick of a switch.
O.D.-Zilla, i think, is the last in a series of builds leading up to his final design, the Mission Control, to which it is very similar. You can see this process (and some more of Rick's incredible work) on his website:
Overdrive for Bass | frequencycentral
as well as in this TB thread (in which there are some soundclips of similar units):
Frequency Central Custom Tube OD on its way!
(Nice Pic is courtesy of Rick at FC)
Cash price is $260.
Open to negotiating trade deal for a BJFE BBBOD, a Mad Professor BBBOD, or a Darkglass B3k/B7k.