Not all 3.5mm connectors are the same
There are several different types of 3.5mm. This CloudBox comes with a TRRS (Tip, Ring, Ring, Sleeve) connector to connect to an amplifier / sound system. Please use the TRRS adaptor provided, or make sure the adaptor used is a TRRS that is CTIA-Style AV (Left Audio, Right Audio, Ground, Video). Connecting TRRS headphones that have a microphone, such as for a phone, will result in a humming sound on the audio.
If you are modifying the adaptor by cutting and connecting the bare wires to connect to a sound processor system, then a TRRS adaptor will be necessary to isolate the ground and prevent the humming sound from occurring.