Opamps impedance and input resistors

[ChangeMe]

hi,
just wondering what the go with input impedance matching is.

if an opamp already has a huge input impedance shouldn't i be able to feed anything into it and not have to match the signals impedance?

thanks.

 

[TheSeekerr]

See Impedance bridging - Wikipedia, the free encyclopedia

Short version: For a Voltage Controlled Voltage Amplifier, such as is typically used in audio, impedance matching is not desirable.

Technical version: With matched impedances, maximum power is transferred. With bridged impedances, minimal power is transferred. This is desirable, because we aren't interested in electrical power, we're interested in the shape of the voltage waveform.

 

[ChangeMe]

thanks that sent me in the right direction, understanding it a bit better now.