If you love so much the british sound and pentodes, I'll come to you with a triode. LOL Yes, some triodes can be used in Eternity in output if I can bias them with less that -54V. Not really sure it makes sense to use this kind of tubes but why not. Let's see how this goes.
So let's look at
GEC A2293, this one was used by others on different threads, usually in input, but for me it's clear an output tube.
I have a nice NOS NIB D-getter pair here, some details:
VB = February 1964 if my GEC date codes tables are right.
Unfortunately this pair is very unmatched. Anyway, no audible difference and I can use it with some caution. I'll show some measurements:
Now, on the amp things stay an idea better (there are always small differences between measurements and amplifier). One sits at 23mA while the other at 16mA. No audible difference, so all these guys spending in vain for matched pairs are, of course, wrong. I said this many times, but well, they feel better using matched pairs, vendors make some money and all are happy. I am also happy, I get the untested/unmatched more easily and cheap. I thank them, I have more money for beer.
Here is the stronger one on DuoVac, -44V for 20mA, but to keep both in line I put around -44.4V on the amp. I prefer to have one tube biased lower than to go too high with the other.
And voila, on the amp with a Philips Herleen 12AT7 put there especially to remove some of the GEC flavour while keeping a decent level of bass. The british flavour is too much for me lately. Sounds sweet, nice and mid forward but it's veiled. A kind of GEC flavoured EL84 sound. Musical with this kind of british sound all love.
And now we reach a nice milesone, this is as far as I remember my first triode on the output in Eternity. Now, according to some GEC flyer because I could not find a datasheet for these, max Va = 300V and max Ik = 120mA, so this is a power horse and can work on more powerful amplifiers. It has 15W so ... I am a lot below.