Quote:
Originally Posted by oldeurope
I can not see another way than the "red line" for the signal flow  . |
Never mind. I was really arguing that because all current, (AC or DC) is suppled by the power supply, there is no such thing as a "siganl path", since ALL components are involved with the flow of current. It's not important.
I have been looking more closely at the theory. You say the AC signal through the tride transformer is divided my mu. This is not so; the AC signal gain through it can be given by:
Av= (ra + Ra) / ra
where:
ra = triode internal impedance
Ra = load resistance (R10 / R20)
To minimise signal loss, it is therefore desirable to make ra large, and Ra small. One method of making ra large would be to use a pentode, but that adds complexity. Another method would be to lower the heater voltage. This will considerably increase ra for a given bias voltage, but also increase linearity!
I still do not see a reason for V1, when you could input the signal directly to the grid of V2, thereby eliminating distortion caused by V1?