Pair of Mullard 12AU7 ECC82 Long Plate Square Getter k61 1955/57 Vacuum Tubes
Date codes k61 B7L & k61 B5I. Pair of Mullard 12AU7 long plate tubes with square getters. These feature the older shield logo and 1955 & 1957 date codes. These test in the 80-90% range, and check quiet on the Amplitrex AT1000.