Originally Posted by Already In Use
If I set the volume at my headphone amp...wouldnt that be as loud as it could ever get?
In a word, no.
Volume knobs act as multipliers (or dividers).
Thus, even if you set the volume knob quite low, if an ungodly loud signal came along (relative to the normal signal level), it would still be very loud.
For a sort of crude example, say the normal level of signal is 1. Your volume knob is set to make everything, say, half as loud, so the signal is usually .5. But then something sends a signal of 300. You will still get a signal of 150.