I am using headphone amplifier ART Headamp 4. It has four output channels (could support four independent headsets at time) but we only need two. Each channel has separate volume regulator and separate output for headphones (the input is shared). Nothing is connected to the output of the unused channels.
I used to turn the volume regulators of the unused channels to the zero position (mute), thinking this kind of switches them of. However I am not sure if this is true. Nothing is written in the user manual.
From general understanding, if we have a headphone (so low power solid state, not a high power tube amp) amplifier that we cannot turn off yet nothing is connected to the output, would it make sense to keep its volume regulator in mute position? Would it impact positively the quality of the overall sound system, the longevity of the amplifier?