(!!!!) (Recommended Pair) 6L6WGB=5881 Sylvania NOS same build 1980 era (81ma and 84ma) (same Gm)

1 Pair) 6L6WGB=5881 Sylvania NOS same build 1980 era

1 tube) 81ma Gm=6200 Sylvania branded GE faded printing - on left

1 tube) 84ma Gm=6200 Sylvania in white box

Matched on Amplitrex

Good Ma 55-70ma

Good Gm = 5500-6000