by EWBrown » Sat Dec 28, 2013 10:19 pm
My hearing isn't the of best, but I have "golden ear" friends who tell me that the 6AV5GA amp sounds very good, as good or even better than 6B4G or 2A3, with the higher plate voltage and current, and hefty PSU filter caps, it delivers a noticeably stronger bass response. I used 3K 10 Watt Transcendar OPTs.
6FW5 has different transconductance and internal plate resistance, and in triode strapped it acts like a "super" 6B4G, same basic operating characteristics, but with higher plate dissipation capability. 6GE5 and 6GV5 are internally same as 6FW5, but in duodecar (12 pin) compactron package. 6GV5 has a plate cap, 6GE5 does not.
For cheaper tube expenses, use 12AV5GAs, Dumont or Sylvania, they cost "chump change" compared o 6AV5GAs (which used to o for "chump change).
I use 12AT7 SRPP driver stages, so the filament can be fed with either 6.3 or 12.6VAC, as needed. 6DT8 and 12DT* are the "cheapskate" equivalents of 12AT7,
with filament connected to pins 4 and 5, no center tap on pin 9.
/ed B
Real Radios Glow in the Dark