12AT7 / ECC81 / CV4024 / CV455 / A2900 / B739 / ECC801S ...
5965: An industrial tube with a mu of 47 compared to 60 of a 12AT7. Low noise and lower gain and can be used in a similar way like using a 5751 in place of a 12AX7. GE, RCA and other USA manufacturers made very nice versions of this tube. Some are "triple mica" and noted for lower microphonics.