Your AC receptacle at home should deliver a pure sine wave. It does not.
Instead, along with voltage and current, it carries an abundance of RFI (Radio Frequency Interference), EMI (Electro Magnetic Interference) and DC spikes all of which seriously impede the performance of any sophisticated audio components plugged into it. A high quality power or line conditioner generally takes care of most of this kind of distortion.
In addition to EMI, RFI and DC spikes there is the added distortion caused by the interaction of the magnetic field generated by each component with every other component in your system. Filtering out these very serious sources of bad sound without also filtering out the high frequency response of the equipment or squashing dynamics is a very difficult task achieved by only a few of the power cable and conditioner companies out there: the few that merit being included among our family of fine components.
At Sound Reference Melbourne you can be sure that when you buy a power product, you are going to get one which cleans and filters the power without affecting the integrity of the AC signal!