It'll probably be a while before I need to replace tubes, but when the time comes, what should I look for? I'm using a Vox AC15, and right now it has stock tubes. Not sure what brand or anything, but they're made in China. Will tubes make a noticeable difference in sound? Are there any specific brands I should look for, or avoid?

Yes. Different preamp tubes can exhibit more or less gain, which effects the sound. Output tubes can have a large impact on tone. It all depends on what you're looking for in tone.
Well I don't really need to much more gain but I would like it sound a bit more ballsy or chunky.
Putting a Tung-Sol 12AX7 in V1 can make it toneful. I don't know what V2 is for really on your amp but using Sovtek 12AX7LPS (matched) as a phase inverter for V3 is good.
Parker PDF30
Vox VT40+
Last edited by OldRocker at Jul 16, 2011,