I know it would void the warranty. What I'm interested in knowing is if anyone out there has inadvertantly or otherwise hooked their LM II or other Mark head up to a pair of 4 ohm cabs, or a 3 woofer cab, and if they had any trouble from this. I'm thinking of picking up an LM II, and for loud gigs I use a 3x15" cab with a nominal 3 ohm impedance (reads more like 2.6) that I really love. I'd imagine being ss and all it should work, at least for the 40 min maximum sets we get around here. Thoughts?