This continues a thread from the old forums. I am trying to figure out how to control the sound volume through the a/b connector for sound from a line level source. I looked at the datasheet for the amplifier chip (TDA7052A) and read the pins directly. I checked the various pins on the amplifier chip itself while raising and lowering the volume, and I'm a little baffled. Nothing changed at all! The power-in is 5v, the positive signal pin stays steady at 2.5v, and the volume control pin stays steady at 4.9v. The data sheet implies, as far as I can tell (being the amateur I am) that the volume is controlled by varying the voltage on the volume control pin, but this is not happening. Any ideas?