[sdiy] Digital VCA - Choosing an ADC

[Olivier Gillet]

Any reason why using a rail-to-rail op-amp, in single supply
configuration, to apply a x0.5 gain to the input signal and shift it
to 2.5V would be a bad idea? The op-amp will also ensure that the
output signal stays in the 0-5V range. You'll have to flip the input
and subtract half your ADC range from it to get a value in the
-2048..2047 range, not a big deal.