wb wrote:
Hi, I have a couple amps I build that use 2A3's in single ended
configuration and I bought four Chinese 2A3's to test the prototypes
with. They worked fine to about 250 plate volts then they would either
start making odd thumping sounds or produce a very audible swishing
sound.
Thanks for your input. By plate voltage do you mean the voltage from
anode to ground? That would consist of Vak (the voltage differential
between anode and cathode) plus the grid voltage.
Many of the sellers on
Ebay are selling 'seconds'. By this I mean they are selling the tubes
others want to dump because they do not meet their criteria for audio
use.
Exactly my thought. Good news: communications established with the
seller and tubes are on their way back to China. Hopefully a refund will
follow
