I really don't understand this strange 'hobby' of turning up volume controls to maximum without anything plugged in etc. - just to see what one hears.

It all sounds a bit like flying down an Interstate at 160 mph and trying to open the doors and 'see what happens' - or maybe trying to throw the car in reverse or downshifting to 2nd gear in a shift-car.

Incidentally - one can really bust their speakers if somehow one accidentally creates some input. Also - all this dizzy 'volume turned all the way up' should ANYHOW always be done with capped inputs.