Signal path:
Mic - stepup transformer - K117 - EF183 (Pleiades V4 battery preamp) - output transformer
This allows generously driving the EF183 and output transformer to get the signal out to be hot.
The objective is getting as much of the electron tube sound with the least possible electronic components. And doing this with as few amplifing stages. So getting a stage to be able to saturate the closest possible to the source, the microphone capsule's electrical output.
By electron tube sound we mean a sound that sounds correct to the listener's brain. An electron tube plays an important part to this objective by its instantaneous dynamic signal processing properties. (Russel O. Hamm)
Would it work?
Adjusting for a loud sounding vocal by overloading or generously driving the second stage which may be an EF183 triode connected electron tube operating with a few volts. (See Pleiades V4 schematic).
The front end K117 JFET can have a wire wound load resistor for low noise. This can be a wire wound multi turn 10KΩ typically potentiometer. The moving tap can be connected to the grid of the next stage through a capacitor. Or even directly to grid to change the bias of the tube. A high series resistance may be needed, see Pleiades V series schematics. So then the high anode to grid biasing resistor may be omitted. This may make a change of behaviour. For example. Normally the elsewhere documented grid neutralization achieves operation at very low anode potential. The variable bias controlling may additionally make easier getting the tube to saturate.
The idea of using a JFET driving an electron tube, both operated from a few volt battery, is to get as soon as possible the peak limiting action of the electron tube for the large (but short in time) parts of the signal.
Letting the output tube and transformer play an overload (peak limiting) game.
Reference:
Pleiades V4, V5 or V6 schematic - euroelectron blogspot
On preserving transconductance - euroelectron blogspot
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