[VA-Exception]

Does anyone know how the bias switches on the back of the dual recs/triple recs etc works? How is it that you are able to swap power amp tubes instantly without having to bias them manually? Does that mean that you can only ever use the tube types specified by how many different settings your bias switch has?

[metalheadpunk]

http://www.mesaboogie.com/US/Smith/biasadjust.html

So the end of the short answer is this: Since a bias supply needs to put out the right voltage and never vary, I wanted to build amplifiers that were individually hard wired to the correct values and NEVER needed adjustment. And for 25 years, that's how Mesa/Boogies have been built.

Time to change tubes? Just plug our tubes into any one of our amps and you're DONE. No tech needed. NO bills and no BS about biasing. And most important: The bias is RIGHT because it can't change!

[VA-Exception]

Awesome

[technomancer]

Note that that assumes you get tubes with the correct value for the amp, ie in the case of what the link says Mesa tubes. You can also get tubes with the correct values for Mesa amps from places like Eurotubes for JJ tubes.