On Sun, Dec 27, 2020 at 08:02 AM, - wrote:
Which 500 series was the 6900 used in? (I believe 6900 a twin medium mu triode.) 6AX7/12AX7 was high mu.
Bendix was (their gone) an interesting company, involved in the aerospace industrial military supply. (A common name during WWII and the 50's, and 60s.
The 6900 was a "hardened" tube.. made to withstand high g, shock, vibration, and was supposed to be more reliable. (well ... for at least the brief time a launched missile lasted.)
Unless one is planning on launching one's class A, audio amp, into low earth orbit... one doesn't need Bendix 6900s.