Fender_Punk
BerriesAndCreamologist
Yeah, I'm sure you can do it. But I don't think it's ideal. Never on a Mesa amp, but I've mistakinly plugged my Marshall cab into several of of the amps' I've had 8 ohm output, and it always takes me a while to figure out why it's sounding a little off/weird/bad, LOL.
But then again, transformers don't have to be as beefy if they're designed to run at 8 ohms max. Maybe they do it as part of the whole Fender heritage of the Mark series. Maybe they do it because they do have to fit a lot inside those smaller headshells. Or maybe they just do it to save some money in iron. Or maybe all of the above.
Honestly, I've seen lots of people complain about how small the transformers are in Mesa amps if you compare them to other amp makers. Even Marshall amps have pretty beefy trannies comparatively. Then again, I don't think I've seen anyone complain about lack of balls or volume in a Dual Rectifier either. But I've also read neither Duals nor Triples put out as much wattage as they claim they do.
In the manuals for the Stiletto Ace and the 5:50 Express both say that they encourage experimentating with mismatching 16 ohms into 8 ohms plug or 8 ohm into 4 ohm. So even if the transformers aren't as big as some other amps they are sufficient to do the job including handling reasonable mismatched loads.