(!!) (Best Overall Single) 7247=12DW7 GE NOS 1970 (1.3ma and 13.6ma) (Highest Ma and Gm)

7247 GE NOS 1970 (SC) gray pinched plates

12AX7 Section = 1.3ma Gm=1900

12AU7 Section = 13.6ma Gm=2500

Tested on Amplitrex

12AX7 Section NOS Good = 1-1.2ma Gm=1500-1600

12AU7 Section NOS Good = 8-10ma Gm=1800-2200