Cascode gain stage

Using two triodes, this circuit can offer a high voltage gain, comparable to a pentode but with less electronics and microphonics noise.
You would probably use ECC83 to make an audio cascode because of its higher intrinsic gain.

PARAMETERS

Select T1 T2 type
V supply voltage
Ω T1 anode resistor
Ω T1 cathode bias resistor
Ω T2 bias resistor
Ω T2 bias resistor

Note: the grid resistor normally found between grid and cathode is not taken into account here, as it does not influence the operating point

SCHEMATICS