Came across this in a book, there's a brief explanation of why there's said resistor in the circuit:
" ... it should be obvious that if we apply an audio signal voltage to the grid (i.e., vary the grid voltage) then current in the valve is bound to vary too. We can put this current variation to good use by putting a resistance in series with the valve so that a corresponding audio voltage is generated across the resistor, which is also called the load. "
Yet I can't quite understand the need for the resistor to be there in order to create the second amplified voltage signal, won't the amplified voltage signal be there anyway whether there's a resistor or not?
Thanks in advance for any replies.
" ... it should be obvious that if we apply an audio signal voltage to the grid (i.e., vary the grid voltage) then current in the valve is bound to vary too. We can put this current variation to good use by putting a resistance in series with the valve so that a corresponding audio voltage is generated across the resistor, which is also called the load. "
Yet I can't quite understand the need for the resistor to be there in order to create the second amplified voltage signal, won't the amplified voltage signal be there anyway whether there's a resistor or not?
Thanks in advance for any replies.