Unmatched power output tubes. Bad idea ?

Even if each tube's bias can be adjusted independently?

Specifically, I have VAC Avatar SE integrated amp and I am thinking of a quad of unmatched used vintage EL34 Mullards.

inna02-04-2025 8:47pm

carlsbad2 Details Discussions Posts This discussion Message User 2,036 posts 02-04-2025 at 09:15pm Copy Comment URL Report Comment Edit Delete Most single ended amps, if bias can be adjusted independently, it is not a problem. Quads can be more sensitive since they operate in pairs. I had a Decware ZMA that had absolutely the best bias system I've ever seen that could balance pretty much any 4 tubes you threw into it. Jerry
Post removed Feb 05, 2025
noromance Details Discussions Posts This discussion Message User 10,454 posts 02-05-2025 at 01:21am Copy Comment URL Report Comment Edit Delete The VAC is a push-pull amp and will likely work best with matched tubes. That being said, you can try the Mullards especially if they look similar and are from a single source, and bias successfully.