(!!!) (2nd Best Mullard Single) 7247=12DW7 Hammond Mullard ribbed plates like new 1964 (1.0ma and 11.8ma)

7247=12DW7 Hammond Mullard ribbed plates like new 1964 

12AX7 Section = 1.0ma Gm=1600 (good)

12AU7 Section = 11.8ma Gm=2100 (very strong)

Tested on Amplitrex

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

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