RC integrator & differentiator

[zesla]

Hi,

As you guys know a low pass RC filter is an integrator and a high pass RC filter is a differentiator. it means that they will alter the waveform of thier input on their output.

Most of amplifiers (specially does which are made by transistors) have a coupling cap at their input's and of course at their outputs (which blocks the DC component of the wave), if They act like an integrator too then the input waveform might change, right? If so then the final output will not change or be distorted??

Thanks

 

[zesla]

It just causes me to think that even for audio works/amplifiers just the frequency is important not the waveform! Any idea please?

 

[crutschow]

A series coupling capacitor would act as a HP filter (differentiator) but the corner frequency is designed to be so low in a normal audio amp that it has no effect on the normal audio frequency band. However if you put in a very low frequency square-wave you will see that the flat portion of the square-wave has a droop due to the differentiation effect of the coupling caps.