Posted by Damir [ 213.202.114.111 ] on March 03, 2006 at 14:11:56:

In Reply to: 300B SE Project, Part 7 - Common cathode 6C45Pi triode driver posted by Damir on February 26, 2006 at 10:11:19:

Today I received my third pair of "Sovtek" 6C45Pi-E. It`s a new production tubes, former pairs were NOS from 70`s/80`s. This pair is well matched and closer to the specs, Ua is about 160V, and µ=43/45. I tried changing Ia through the tube(s) in 1mA steps. IME - lower current "sounds" darker and less sharp/rough. About 9-9,5 mA sounds best for my ears, although I can "swear" that I heard a little sound differences between the 6 tubes I have, too.
We can (safety reasons) "drop" the B+ a bit, on about 400V. I didn`t hear the difference.

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