I am continuing to tweak my little single-ended build and I’m thinking power tubes now. Currently there is an old Admiral tube in there that I got on Ebay a while ago. I don’t have any complaints with it but at some point I’ll need to do some experimenting.
One 6V6 that I’ve had terrific luck in the past with is the Electro-Harmonix 6V6 EH. I’ve used them in single ended amps and push-pull. A a really nice thing about them is that they can be run at all sorts of voltages and still sound great. I’ve run them at 425vdc and at 335vdc and it always delivers. They have a nice crunch to them, almost like an EL84.
At some point I know I’ll try one in my current project. It’s tough to beat a great old tube but I’ll give the EH a chance for sure.