12AZ7 GE black plates “”D”” getter halo NOS 1955 (11ma/7.5ma)

12AZ7 GE black plates “”D”” getter halo NOS 1955

11.0ma Gm=5800

7.5ma Gm=4500

McIntosh MC275

guitar amps – sub for 12AT7 or 12AY7