12AD7 (12AX7 variant)
Miniature 9 pin dual triode
Series heater: 12.6v-.15 amp/Parallel heater: 6.3v-.3 amp heater
NOS
International Servicemaster/EI made
Knock off Telefunken flat long plate
Leave it to ICC/International Service Master for one size fits all,
we'll make it work attitude.
Some EI ECC83 were selected out for certain characteristics,
lower microphonics to meet the 12AD7 spec.
We won't guarantee this.
We sell all their EI 12AX7 based variants as a 12AX7/ECC83 only.
With ICC Servicemaster, you never knew what you were getting.
It could be then current production or some old vintage gem.
A gold tip indicates Gm tested tubes for section balance.