Hi Mike,
Old 741 opamps won't work in that circuit:
1) They won't work with a supply of only 5V.
2) Their output can't swing anywhere near +5V and ground like the rail-to-rail MAX opamp.
3) They are very noisy so with the gain of 101,000 in this circuit before the peak detector, their noise will be detected instead of the signal.
There are lots of other low voltage, rail-to-rail and fairly low noise opamps in the world.
I would make it with single TL071, dual TL072 or a quad TL074 low noise opamps, and use +12V or two 9V batteries to power the circuit. Because these low noise opamps are so popular for audio circuits, they are actually cheaper than 741's. :lol:
With the higher supply voltage, the output swing will exceed the safe level for a microcontroller.