(!!!) (Recommended Pair) 12AZ7A GE Admiral black plates NOS 1960 (10/9ma and 9.2/10.5ma) (McIntosh MC275)
(!!!) (Recommended Pair) 12AZ7A GE gray plates NOS 1969-1970 (8.2/8.0ma and 8.7/8.8ma) (McIntosh MC275)
(!!!) (Recommended Pair) 12AZ7A RCA black plates NOS 1970's (8.6/9.6ma and 7.6/9.2ma) (McIntosh MC275)
(!!!) (Recommended Pair) 12AZ7A Sylvania black plates NOS 1960's same build (8.2/9.8ma and 8.4/9.8ma))
(!!) (Recommended Pair) 12AZ7A GE Admiral black plates NOS 1960 (8/9ma and 8/10ma) (McIntosh MC275)
