@immatthewj Not exactly. But its likely that one tube type in that list will perform better than others. That’s a bit different from saying that it will ’work’; sure it will play but the output transformer should be optimized for a particular tube.
@atmasphere , although I do not understand circuit topology what you write does make sense. I’ve often found that tools that are advertised as fulfilling multiple functions do not work as well as a tool that is designed to perform one specific task. And hand tools are much simpler to understand and work with than circuits are.
As far as rolling tubes, I am not trying to speak for Dennis Had, but from reading the writeups he provides for several of his products (including the V12, from which I sort of recently quoted the manual), I sort of get the impression that he likes tube rolling. I remember reading one of the blurbs he wrote for one of his fairly recent SET amps, and he described it as (I belive the words he used were) ’a tube roller’s dream.’ Anyway, as far as the V12, after reading through the recent posts I am going to assume that it was "voiced" (I’ve read that term elsewhere) for the EL34 and after reading the recent responses on this thread, I am not going to mess around with other tubes. (Although I do have three different quads of 6550s for another amp that I am not using right now, and if worst came to worse, I could drop one of those quades in and bias the amp for two tubes per side). I’d also note that in the manual, Mr. Had writes about the virtues of the triode circuit toplology, and from what he writes about the V12, I am assuming that he includes the V12 in pushpull. Meaning that I guess he probably "voiced" the V12 in triode, but for at least the present moment, I am preferring UL.
@xenolith , I was going to jokingly type thgat you are a buzz-kill, but a lot of jokes are not taken as such. In reality, I wouldn’t be surprised if you are correct. I don’t have much of a grasp on the subject of circuit topology and back when I was setting up my system (the ’90s), I didn’t have a computer and didn’t know about A’gon, and what I learned was from reading Stereophile, what dealers told me, trial and error, and what manufacturers and their tech guys told me when I called them to ask questions about their products.
Anyway, if I NOW had the wherewith all to start completely over from the ground up, I would do a lot of things differently. However, I retired early and I made a few bad life choices before Idid, so I am probably going to find a way to try to be as happy as I can with what I have. But I will add that before the V12 I had a couple of strictly UL products, including a pair of ARC VTM120s which I have referred to previously in this thread, and if they were more relaible than they turned out to be, I’d still own them, and although aural memories (at least mine) are often flawed, going from the ARCs to the V12 was, at best, a lateral move. As far as the sonic presentation, that is. But when I flip the switches to turn the Cary on, I do not have to cross my fingers, and that is worth something.