The 100uF supply bypass capacitor is good with a battery, but it might not be enough to stop hum from your power supply.
Most low dropout regulators must have a pretty big output capacitor or they oscillate. The one I used needs 100uF. A 7805 or 78L05 is fine with a smaller output capacitor, a 0.1uF ceramic disc is recommended on its datasheet.
I mark where the tracks need cutting with a marker then cut them before mounting and soldering the parts.
Most low dropout regulators must have a pretty big output capacitor or they oscillate. The one I used needs 100uF. A 7805 or 78L05 is fine with a smaller output capacitor, a 0.1uF ceramic disc is recommended on its datasheet.
I mark where the tracks need cutting with a marker then cut them before mounting and soldering the parts.