Don't get confused by me calling it a low pass filter, it is, but just for the supply voltage, it's not in the signal path. Its only effect is to filter supply ripple and I agree with NanoFarad, I'm sure the engineers who designed the circuit already chose the component values the circuit requires considering the incoming ripple and the high PSRR of the opamps. I mean, if I was recapping the thing and happened to have a bunch of 100u caps in stock (which usually I do) but no 47u's, I'd use them, no harm in that, but I wouldn't expect that to make any audible difference at all.
