LM1875T freq. response

[jamal]

hi everbody, I did a simulation for the LM1875T and the freq. response is up to 100khz. after 100khz it begin to roll off. do we need any capacitor to limit the bandwith within audio spectrum.

[AndrewT]

Yes,
fit a low pass and a high pass filter at the input of the amplifier.
These passive single pole filters determine the passband of the amplifier.

[jamal]

which capacitor suit best for audio amp.....thanks

[AndrewT]

for which filter?
And at what cost?

[jamal]

I mean the input capacitor. cost? what is the most expensive in the market, are they really effective/

[AndrewT]

there should be two filters at the input.
The high pass needs a plastic and metal cap. Try not to use an electrolytic.
The low pass also needs a plastic and metal cap, but can make do with mica and metal.