EtherealWidow said:
Yeah I read an article and it said that halving the impedance would wear the tubes faster, and doubling could potentially cause flyback currents. It's nuts how complex all this is.
Any impedance mismatch causes additional stress on the output transformer: go one way and you load the primary winding; go the other way and it's the secondary winding ...nature of the beast. Additionally, how
much the mismatch determines the stress put on the tranny. So going from 4ohm to 8 is much less difference in loading than 4ohm to 16.
These are electrical "truths" if you will. But all that said, additional "load" doesn't mean "bad" by default. Kind of like saying loading your car up with passengers and luggage is "bad" ...there are built-in design parameters; just don't exceed them.
I've read, for example, of numerous failures of vintage Marshalls' trannies dying if you mismatch impedance (or even look at em funny
). And some of their modern offerings are scarcely better. This is no slam on Marshall; this is simply observation of people's failed trannies on their Marshalls. Contrast this to Mesa's failed trannies. ...cricket...cricket...what? no failures? OK, I'm no tech, but in my over 10+ years of using a variety of Boogies live, full-band practices, at home (and cruising forums like this
) I have not heard of a single failure to any transformer, let alone failure due to impedance mismatch.
Moral of the story: say within the design parameters ...the lines are our friends. Mesa says one-order of mismatch is well within their design (and not to drop below 4ohm final load), and they are confident enough about it to put it in writing and back it up with a warranty. Not to mention their stout trannies clearly bear this out. So I think you can relax and not overthink the matter. Play your boogie and enjoy the tone!
Edward