5879 preamp tube

[freepressright]

I realize this tube is a pentode, if memory serves me correctly, so does that mean other pentode-type preamp tubes will work as substitutes? I just bought about 2,500 NOS tubes of various types, but unfortunately there were no 5879s there. I did manage to get a bunch of classic 12AX7s, 12AT7s and 12AU7s, but nothing of the 5879 variety.

I have a filmosound amplifier that takes a 5879. What are some examples of acceptable substitutes? Any help is much appreciated. Thanks!

[Fretts]

This site lists the EF86 as similar but not identical. It may be necessary to make some changes to the socket or even the components surrounding the tube:
http://www.radiomuseum.org/tubes/tube_5879.html

[soundmasterg]

It is 5879 or bust, unless you want to change the socket and the circuit around it to voice it for another tube. The EF86 has a lot more gain than the 5879 and is more imcrophonic. There are tons of great quality NOS 5879's around for good prices still.

Greg

[Enzo]

AES has them for $8-9 each

http://www.tubesandmore.com/

[freepressright]

I know they're out there, and what I'll most likely do is stock up on them, but I'm left to wonder why they wouldn't have used a triode like anything in the 12AX7/12AT7/12AU7 family instead of the 5879. I don't hear anything more special about the 5879 than the 12AX7 or any of its other similar family of tubes.

[Regis]

My Kay 720 uses 5879's, every one I've tried has been microphonic as hell.

[Diablo]

I've got 5 NOS 5879 tubes in front of me. Two RCA and three GE. Would you care to trade? I'm looking for NOS 12AY7 tubes.