Hello, I am just trying to understand the concept of diode clipping.
Why can you not just use a resistor to clip the voltage, rather than using a diode ?

Thanks for any help.

 

Simply stated, the resistor will always conduct, while the diode will only conduct after the voltage across it becomes high enough to bias the junction into conduction. If you have a simulator handy, try it to see the difference.

Another exercise - assume you have a sine signal from a source with an impedance of 10 ohms. The signal excursion is 14 volts peak to peak. The amplifier input is 20K. What value of resistance would clip the signal peaks at +/- 12 volts?

Remember that clipping stops the signal from going more positive or negative (signals have flat tops instead of peaks). Using resistors may load the signal and act as an attenuator, but won't clip.