Date: Sat, 10 Sep 88 12:06:32 EDT
From: kludge@pyr.gatech.edu (Scott Dorsey)
Subject: Different Tube Brands

I knew that tubes didn't all sound alike, but I didn't realize the difference
in the noise floor is as great as it is.  One of the 12AX7s in my tape deck
became heavily microphonic, and I swapped it (a Mullard) with a brand-new RCA,
and got a much higher noise level.  Putting an old Amperex in reduced the noise
to below the level of the original Mullard, and a Grass Instruments "Selected"
Telefunken tube was even better.
   How come nobody tells me any of these things?  Why do I have to find them
all out for myself?  And just what IS a good 12AX7?  How about some of those
Soviet and Chinese tubes I keep hearing about.

And, yeah, I like the 12AX7.  I'm probably alone.