Transistor biasing resistors

[EricKnabe]

When I bias a transistor stage with a voltage divider, do the two resistors that make up my voltage divider have an affect on the audio signal going in? You'd think resistors going parallel to ground would have some effect on the sound, but that's not ever mentioned as a consideration in any reading I can find about setting up the biasing circuit for an amplifier.

[antonis]

When I bias a transistor stage with a voltage divider, do the two resistors that make up my voltage divider have an affect on the audio signal going in? You'd think resistors going parallel to ground would have some effect on the sound, but that's not ever mentioned as a consideration in any reading I can find about setting up the biasing circuit for an amplifier.

It depends on what exactly "effect on sound" means..

Without any capacitive/inductive reactance, the only effect is signal loss..
(from voltage/volume point of view..)

In case of an input coupling capacitor, a HPF is formed of corner frequency calculated from f = 0.159/(R*C), where C= cap value & R = parallel combination of voltage divider resistors AND transistor input impedance..
(the latter being [ h_FE times r_e + (h_FE +1) times (Emitter resistor value) ], where r_e = 1/g_m = 0.026/Emitter(Collector) quiescent current

P.S.
Same also stands for output (cascaded stages or just single load with coupling cap..)
R should be the parallel combination of Collector resistor and load or next stage equivalent input resistance ..

[PRR]

> not ever mentioned as a consideration in any reading I can find about setting up the biasing circuit for an amplifier.

If we have to tell you EVERYTHING we'll never be done.

IMHO, we really should not be thinking about amplifiers, or transistors, or biasing, before we THOROUGHLY understand DC and AC networks.