Vintage Sylvania RQ-3746 Quadrophonic Receiver For Parts Repair VIDEO DEMO! This receiver powers on and there is a hum noise. It goes away after a few seconds and you’re able to operate it. I tested the Aux input and one channel is lower in volume than the other. The FM tuner is more evenly matched. You’re able to use the joy stick to adjust the volume. I did not test the secondary speaker outputs (Remote) The volume, balance and tone controls seem to work. Feel free to reach out with any questions.