Manufacturer Amperex. Tube Code I65 ^ 7B1 (^ = Amperex manufacture code) 7B1= 1967. Number 12AX7 ECC83. T he Tube tested at 86% (2.031 x 42.7 = 86.7 %). 32 = 65% of the value of a new tube. Rated 86 %.
Manufacturer Amperex. Tube Code I65 ^ 7B1 (^ = Amperex manufacture code) 7B1= 1967. Number 12AX7 ECC83. T he Tube tested at 86% (2.031 x 42.7 = 86.7 %). 32 = 65% of the value of a new tube. Rated 86 %.