A Larger gauge power cord may help for high current components. A power cord without ground may change things compared to one with a ground - due to ground loops. Otherwise, unless there is a filter built into the cable then differences should be negligible if the power supply of your equipment is well designed.
If your equipment has a lousy power supply design then all bets are off - turning on the light or even your fridge may affect the sound and so might simply unplugging the power cord and plugging back in. Perhaps, in this case, you might even worry about the electrical transformer on your block or the kind of coal burned at the power station!
A well designed power supply should isolate the line level audio electronics from mains noise and provide clean power as required by the circuits - pretty simple really.
If your equipment has a lousy power supply design then all bets are off - turning on the light or even your fridge may affect the sound and so might simply unplugging the power cord and plugging back in. Perhaps, in this case, you might even worry about the electrical transformer on your block or the kind of coal burned at the power station!
A well designed power supply should isolate the line level audio electronics from mains noise and provide clean power as required by the circuits - pretty simple really.