SpeaKa Professional Erdschleifen-Isolator Audio 2.0 (3.5 mm jack) Extension via 2 leads

This passive device reduces ground loop interference in audio systems, and can easily be added to new and existing systems. Interference in a ground loop circuit is caused by voltage potential differences that makes the ground wire no longer have a ground potential. This device isolates the DC connection between PC and audio components, preventing current flow. This eliminates humhiss, buzz, and other electrical background noise caused by ground loops.The product is small, lightweight, does not rely on external power suply. It works with any audio device that has a 3.5 mm jack.

Price: £ 26.99 from Conrad Electronic