Review on YAMAHA A-S501BL: Powerful Natural Sound Integrated Stereo Amplifier in Black by Amy Hernandez

Right out of the box, the balance controller didn't switch smoothly from one channel to the other. There were some subtle variations on either side of the straight line. But instead of a smooth nulling on one side or the other, there is a sharp cutoff on both sides after the lower volume channel hits about 30%. It's also not possible to listen with headphones when the speakers are on. . Right next to the jack is a switch that allows you to turn speaker sets A and B off. All other amps I've used turn off the speakers using such a switch, rather than just plugging in headphones. As a detail, the knobs are made of cheap plastic and turn too easily. A light tap or accidental touch of the controls will change their settings. All in all very bad design. I arranged for the device to be returned within minutes of its arrival.