This needs a "pi" filtering network and what I gave you is a "Pi" RC filter for 60 to 120 Hz. There is math that can be used to determine the exact values of the resistor and capacitor values. What you have here is like using a shotgun to kill a fly. It works...but you can achieve good results if you know exactly what you are trying to filter. A scope or a good RMS VOM is essential.
A LC network is actually more efficient and provides better filtering, however, most people don't have a spare 100 mH choke lying around.
Rcaman
