I have a 70V (Pyle PMX3500PH) connected to six speakers drawing 30W each connected through an OSD volume control (SVC 300). Since it's a transformer-based volume control, when you turn it all the way down, I am assuming that this appears to the amplifier as if there is zero load on the amplifier. With zero load, then you essentially have a voltage differential but no current coming out of the amplifier.
Is it bad for the equipment to leave the amplifier running with music playing through it, and have the volume all the way down (zero load on the amplifier) or should we turn off the amplifier every night? Does having the volume all the way down look like an open circuit with infinite impedance on it?
EDIT: For more clarity based on comments: The question is based around having a centralized amp in an inconvenient location, with a volume control knob placed in each room that can control the audio level. If all of the volume controls are set to zero, then there is effectively zero load and zero current. (obviously ignoring leakage here). So is there a fundamental problem with running an amplifier without a load (does it cause some sort of issue with the transformer on the amplifier itself).