To use these as 12AX7 replacements you have to wire two tubes in series to get the 12 volt
equivalent.
The 6H2N-EB Vacuum tube, also known as a 6N2P tube has a
slightly higher gm then the 12AX7 / ECC83,
giving it more power and authority than the 12AX7 / ECC83.
6H2N / 6N2P tubes make great replacements when re-wired.
6H2N / 6N2P double triodes; close by characteristics
to the ECC83 ~ 12AX7. They have the same pinout only the
filament is 6.3V (they draw about 0.34A filament current)
These can easily be rewired.
These tubes are used extensively in Red Bear guitar
amplifiers.
Electrical Data:
Heater Voltage .................... 6.3
Heater Current .................... 0.34 A
Preferred Substitutes .......... 6AX7, 6H2N,
6H2Npi, 6N2, 6N2P, 6N2P-EV, 6N2P-EB, 6N2pi
Substitutes when rewired .............12AX7,ECC88