IBM 5965 Tube Question

[Zulubilly]

I just came across some NOS tubes packaged 3 per pack on Olson Electronics header cards.  They were listed as 5965 type and replaces 12AX7.  They were all IBM tubes and one GE.  These were a little dirty( the plastic from the shrinkwrap was stuck to each tube) so I opened them  and cleaned the gunk off and straightened the pins and they all tested excellent.

My question is has anyone used these as a replacement for a 12AX7.  If so do they do the job properly.  I see where they can be used as a replacement for a 12AT7, and possibly for 12AY7 but not 12AX7.

I need some info.

Thanks,

Zulubilly

[loudthud]

I've never used a 5965. The gain is on the low side, close to a 12AY7. The heater draws 50% more than a 12AX7 but that's usually not an issue except in series connected heaters like the re-issue Model T, the 300T and the solid state 1200S.

[Zulubilly]

Thanks,

I guess I will just sit on these til they are needed for something else.

Zulubilly

[Soundmasterg]

Yeah they work good as a 12AY7 replacement, though they are sometimes microphonic. Cool tubes though.

Greg