What Is Amplifier Bias?
A bias is an inclination of one sort or another.
For example, lift up one end of a long board. Now, things can roll down
it! Things can't roll down a board that isn't
In an amplifier, a bias is a steady
or a steady
voltage that stays in the circuit even when the volume control is set to zero.
Vibrating guitar strings produce a fluctuating current or voltage (a signal) that gets
superimposed on the steady bias.
The guitar signals can be
by the amount of bias.
Examples of how an amplifier's bias can affect a sine-wave signal:
Pure Sine Wave
Here, the wrong bias is causing
unbalanced clipping of the signal,
Here, over-biasing is causing a
musical, even-harmonic blip at the
zero-crossing point of a
TOP OF PAGE