It seems like a nice option and I don't want to devalue what you say but from trying the Univalve my opinion is that you would hear the difference between the tubes but only in that particular circuit, which is / sounds a bit quirky, unlike any other (vintage style) amp.Hyphen Nation wrote:If you really want to go all tube/tone quest, what about getting that Univalve that is in B/S/T and swapping out tubes to get a sense of what you are after? You can hot swap the Power tube and the two pre-amp tubes. The "roll" channel cuts one of the pre-amp tubes out. What's nice, is that it let's you really hear the difference between say a 6550, an El34 and a 6L6. Pre-Amp tubes really change based on manufacturer…this is a slippery slope, but if you can find an old stereo place or a music shop with a bin of used tubes, you can totally score a range of tubes to try out for almost no money. I have a small shoe box full of vintage tubes that probably didn't cost me more than $30…the pre-amp tubes are a different story…a NOS high gain pre-amp tube is worth it's weight in gold, and typically won't burn out.
Honestly, power tubes don't solely contribute to a certain sound, it's only in conjunction with the preamp and power amp circuit that they give a certain tone.
I've heard 6V6's sound like EL84's (Bogner Duende), EL34's sound like EL84's (Matchless Phoenix), 6V6's sound like EL34's (Marshall Studio 15), EL84's sound like EL34's (Marshall 2061), EL84's sound like 6V6's (Peavey Classic 30) and those are just some examples, there are more.



