Quick points:
- Butterworth filters have lower roll-off than elliptical for the same order, and group delay is not constant (phase issues).
- Most op-amps do not have the bandwidth (small or large signal) to deal with the fast DAC output glitches (which are almost impulses) and do not behave well when slew-limited. Some behave quite badly, in fact.
- I am confident 0.1 dB ripple is inaudible and buried by room and speaker variations. Still, somebody will probably say they can hear it...