Model:
12DW7/7247
Brand:
EI
Classification:
Twin Triode
Model:
12AY7
Brand:
General Electric
Classification:
Twin Triode
Model:
ECC83/12AX7
Brand:
Mazda
Classification:
Twin Triode (grey plate)
Model:
ECC83/12AX7
Brand:
Mazda
Classification:
Twin Triode (silver plate)
Model:
ECC83/12AX7
Brand:
Mullard (modern logo)
Classification:
Twin Triode
Model:
ECC83/12AX7
Brand:
Philips Miniwatt, Gt. Britain
Classification:
Twin Triode
Model:
A2900 (12AT7/ECC81)
Brand:
GEC
Classification:
Twin Triode (ultimate 12AT7)
Model:
12AT7/ECC81
Brand:
Amperex
Classification:
Twin Triode