"Arfa Daily"


If you check a 12AX7EH, 12AT7EH or 12AU7EH, you get 32 ohms between
pins 4 and 5.

Check any other brand and the reading is 10 to 14 ohms.

The EH ones still draw 160mA at 12.6 volts like the others.


** What are pins 4 and 5 ??



** I thought it was obvious.

The filament wire is not made from tungsten, as in all the others.


Well yes, that much is obvious, but if the heater current ends up at the
same as for other makes when it has reached temperature, then whatever
they do use must have a negative temperature coefficient,

** FFS read my post before you reply with such nonsense !!!!!!!!!!!!!


** Been there, done that.

12.6 volts at 160 mA = 79 ohms.


What, both of them when they have full volts on ?


** What are pins 4 and 5 ??

FFS read my post before you reply with such nonsense.

The resistance goes UP from 32 to 79 ohms when power is applied.

Shakes head, over and over............


..... Phil