microphone amplifier

[shaffaaf27]

hi, i have a microphone amplifier from a Versitile Amplifier Module which has an imput RMS of 1.23mv and output of 1.23V.

it needs to have a bandwidth of 40Hz to 20KHz, and a balacned input impedance of 600 ohms.

For some reason it needs 2 opams in cascade, A differential Voltage Amp, and a non-inverting amp.

what i want to know is why it needs 2 op amps in cascade, and what are the advantages over using 1, and the disadvantages?

 

[audioguru]

With a voltage gain of 1000, a TL071 low noise audio opamp has a upper frequency cutoff of only 3200Hz. If two opamps each share a gain of 32 then the upper frequency cutoff is 80kHz.