Stereo audio isolator

This is a simple transformer audio isolator. It provides common ground isolation and reduces common-mode noise - exactly the kind of hum or buzz that creeps in when a radio and a PC sound card are connected together and share a ground reference through both the audio cable and the mains earth. Inside the enclosure are two audio transformers with 3.5mm jack sockets and a 10cm pigtail, breaking that shared ground while still passing the stereo audio signal through cleanly.

Use it as an audio signal isolator between an RX/TRX and a PC sound card, an audio amplifier isolator, or as a general-purpose measurement tool.