Very True. I like very cheap power tubes. Russian 6N13's or whatever they are called. Others would frown. However I have tried all the other 6AS7 type tubes and the Russian hits my taste. Problem is getting quiet sets.
Just my opinion. Take it with a grain of salt. Here is my ranking (first worst to last best)
Sylvania 6F8G. Not much fun. Similar to 6SN7
RCA Roundplate. Nice tube. Better than RCA 6SN7 type. It beats my 6SN7 Greyglass and clearglass.
RCA Flatglass. Very nice. Better than the 6SN7 type with the same plates. No treble roll like 6SN7. Treble is sweet. Very Dynamic tube. Not much colour.
Ken Rad 6F8G. Not tried. Suppose to be good. Similar to RCA flateplate structure.
Tung Sol 6F8G Flat plate. Not tried. Looks like a Ken Rad or RCA plate structure. I suspect this is a disguise. A classic rebadge or contract make. I could be wrong tho.
Tung Sol 6F8G round plate. Not tried. I will listen soon. I can get my hands on a set to try. From what I have heard the best.
NU round plate. My favorite. Hits my emotional button. Lush. Great midrange. Better soundfield than the others tried. I can't bring myself to try TS RP as this is so good. A whole other level to anything I have heard. I'm stocking up.
Edited by Badas - 3/22/15 at 2:01pm