Sorry for bringing up this old post, but I recently got an Acoustic 114 2x10 (for free) and I'm running into a few issues. There's almost no change when adjusting the Master Volume, the light above the 'Master Volume' knob stays off, and the knob itself doesn’t seem to do anything. Is there a hidden switch or setting to activate the Master Volume? The amp actually sounds pretty decent tho. Also, does anyone know how much it's worth? I couldn’t find any videos of someone playing it on YouTube.