(!) (Recommended Pair) 12B4A Sylvania NOS 1960”s (26ma and 27ma)

1 pair) 12B4A Sylvania NOS 1960”s same build in white boxes
1 tube) 27ma Gm=5800 (red printing)
1 tube) 26ma Gm=5800 (white printing) ITT

Matched on Amplitrex

Vplate=140

Vgrid=-15V

Good Ma range 25-40ma

Good Gm = 6000

– Mapletree Ear+ Purist Headphone amp
– Mapletree Audio Design Ear+ Purist HD 2007
– Ultra-Fi linestage
– Graham Ingle, Black Cat Electronics
– Experience Music DHT