Valve preamp.

[ppppenguin]

This design is OK as it has resistors in the grid of the CF stage and between the cathode and output. But beware of CF (and emitter follower) stages driving capcitative loads. They can oscillate rather well, often at frequencies your scope can't see. Capacitance at the cathode/emitter is reflected back as a negative impedance at the grid/base. Hence the need for a grid/base stopper. A bit of resistance in the output, to keep the capacitance away from the cathode/emitter also works.