by EWBrown » Fri Aug 03, 2012 6:30 pm
If 6BM8 / ECL82 / 6Ф3П are hard to find, or too costly, there are low cost replacements: 8B8, 8V filament; 11BM8 11V filament, 12V is OK; 16A8, 16V filament, and 50BM8, 50V filament. These can be operated in Pentode or UL mode with good resullts, and triode mode for lower output power.
Same pinouts, same basic triode and pentode operating characteristics, just different filament requirements.
I've used 11BM8s and 16A8s in numerous designs and builds, including two modified K-502s, which can use either tube type, with a filament voltage selector switch hidden under the chassis.
Then there is the Russian 6Ф3П, which is a direct ECL82 / 6BM8 plug in replacement. I've also used these, they are generally quite good.
The Chinese 6F3 is of variable quality, some are good and some just plain stink...
6GV8, 9GV8, 10GV8 and 11MS8 are similar, but their pinouts are not 6BM8 compatible. These tubes are not good for Ultralinear operation - I've tried them, and they definitely do not like operating in this mode. Perhaps they need other than a 40% UL tap, perhaps 50% ?
/ed B
Last edited by
EWBrown on Wed Oct 15, 2014 9:02 pm, edited 5 times in total.
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