[Hallicrafters] re: 6V6's - NOS or newly manufactured??

[Andy Bullington]

Depends on the brand etc. I have had the new ones fail after a comparitively
short time. (6 months) I've never seen this happen with NOS 6V6s.  The
general thinking in the audio community is that the newer 6V6s don't stand
up quite as well and don't sound quite as good. and its a fact that some
will not handle the same voltages as a good NOS tube. I doubt serioulsly if
you will notice a difference in the sound of, say, a new Electro Harmonix
(Russian) 6V6 and an NOS RCA , Brimar or Phillips...
but a Brimar will last a very long time.
 But in a receiver I doubt you will be testing those voltage limits. If you
are running a pair be sure and get a matched pair...whether NOS or new.
The prices of quality NOS 6V6s is considerably higher than Eastern European
or Chinese tubes.
                 Andy W1AWB