Add amplifier before attenuation network

From the previous analysis, we can know that adjusting RPi and Coral can make the RC attenuator boost or attenuate signals of various frequencies
. However, please note that the so-called boost and attenuation are for flat characteristics. Due to the addition
of the RC attenuation network, the flat characteristic as a benchmark is attenuated by about 20dB compared with that without the RC attenuation network. This
loss is usually compensated by adding an amplifier. The voltage gain of this amplifier should be 20dB (that is, the amplification is 0). Should
the amplifier used to compensate for the attenuation loss be added before or after the attenuation network ? Because if you attenuate first and then amplify
, the signal-to-noise ratio will deteriorate when a small signal is input, so it is often added in front of the attenuator, that is, amplify first and then attenuate, as shown
in the figure.
    The volume control potentiometer RP3 should be placed in front of the amplifier to avoid When the volume is adjusted, the load on the RC attenuator
is caused to change.