Controls 1. 2. 3. 4. Output level control Power LED LO CUT switch 3.5mm headphones jack output Operation Slide front panel upwards to install 9V battery, then close the cover. With the LEVEL control down, connect headphones to the 3.5mm output jack to power up the receiver. The power LED will light up. Turn up the LEVEL control and walk inside the induction loop field (ensuring loop amp is on with signal connected).