CAUTION: For advanced audiophiles ONLY. Use the Magnan Audio scheme for constructing capacitor banks that plug into various unused wall outlets around the house, audio and non-audio circuits. These capacitor banks comprise capacitors of specific values and are connected to a power cord so some skill in soldering is required. The capacitor banks act as high pass electrical filters and are VERY effective.
https://positive-feedback.com/pfbackissues/0706/magnan.tweaks1.7n6.html
https://positive-feedback.com/pfbackissues/0706/magnan.tweaks1.7n6.html