Out of curiosity, I tear-down this iRig audio interface that I used sometimes to record my guitar solo. I didn’t expect the circuit to be complex since this device is cheap (must be fake), only cost around $3.
This device connects to the 3.5mm TRRS headphone-mic combo jack of laptop or celfone.
About the circuit
The circuit only uses 1 FET or Field Effect Transistor, a couple of resistors, capacitors and ferrite beads. I was a bit surprise to find a ferrite bead on this device. They are usually common on high frequency circuits and audio are not high frequency.
I will be planning to make a simple audio mixer with 2 inputs for you guitar and mic based on this circuit. This mixer will be useful for live streaming in facebook or youtube. Please like my facebook page and subscribe to my youtube channel so you will be updated when this project is available. 🙂