Fixed-bias cathode follower

Circuit #3

A cathode-follower stage, biased by a resistor bridge.

The resistor bridge divider imposes a constant voltage Vg on the tube’s grid; the tube attempts to reflect this very voltage on its cathode. The current is determined by Vg, the cathode resistor, and the capability of the tube to provide the corresponding current.

A too low value of Rk may prevent the solver to converge.


Select T1 type
V supply
Ω bias resistor
Ω bias resistor
Ω cathode output resistor