pelliott wrote:Once you're getting into the territory of a large amp such as that is the sound difference between a 6550 and a KT88 THAT much to anybody but those with an extremely trained ear?
Tubes sound very different from one another mostly because the circuits that drive them are different. People think EL84's are the quintessential British sound because of the Vox and Marshall amps, but really you can make an EL84-based amp sound every bit as American as a 6v6 amp. With that said, my Fryette Memphis uses EL84s, and the sound is a cross between a Hiwatt, a Vox, and a modded Marshall JMP. Whether it's the EL84s that lends it a Vox tinge I don't know, but I'll hazard a guess that it's more to do with the circuit than the tubes and the requirements the EL84 needs.
However, changing tubes in an amp that has the same circuit and only requires a slight bias change, and you're biasing both sets of tubes neither hot nor cold, you won't find that much of a difference. It's a big enough difference for ourselves to warrant the consideration, but not to others. Others don't really care, unless they're gear nerds and are really into the specifics of their favourite band's sound and gear. In a studio it can matter, because the desire to compare the two recordings side-by-side is present and strong. But as Skip said, on stage it's neither here nor there.
