Good day, gentlemen. I'm here, arriving from the Vacuum Tube Audio Forum. I have a modest collection (compared to fellow collectors), and I can highlight the Telefunken RS237, STC4242a, United, and Amperex as top-tier. RCA GE are very good, but in a different league. Japanese and European manufacturers have metal plate versions that sound very good, but they don't have the same heat dissipation or filament voltage. Listening to them requires adjustments or dedicated amplifiers.
