E80F or EF806S what's the diff??

[SDOLMER]

I recently purchased 13 Mullard E80F tubes, to replace a EF86 in a microphone.
All were apparently unused. 2 didn't work, 9 sounded about the same, and 1
sounded great. The one that sounded great seemed to be of a latter vintage than
the others. Does anyone know of differences between vintages? Also can a
Telefunken EF806S be used in leu of the Mullard E80F? Would there be any
advantages? Which is the better tube, and why? And for what? Excuse me if these
are dumb questions, as I'm new the the tube world.

Steve
sdo...@aol.com

[David Hinson]

I would say a Telefunken EF806S would be a good replacement for the original
EF86 in your microphone as the EF806S is a premium version of an EF86.

I recently tested a whole bunch of EF86 types, both new and premium N.O.S. for
a mic pre-amp design I was building. My favourite was the TFK 806S and/or the
different pinout version-EF804S. My second favourite was, believe it or not, a
Tesla EF806S which was supposedly a copy of a Telefunken. Actually it's a
little more balanced than the Telly and cost about a fifth of the price so I
went with that. I managed to get my hands on about 25 of the Tesla versions
but if anyone knows of any more for sale please let me know.

All the best, David.