Not a good idea to mess with cables if the power amp is powered up. You can easily ground the input and put a high volume BLAAAT through your speakers.
Unplugging preamp, amp and cable while music is playing
I’m wondering what typically happens if you turn off the 1) preamp, 2) the amp, or 3) speaker cable while music is playing, say you accidentally stripped on the power cable of your preamp, amp or the speaker cable and they broke. Does any of these condition will cause any damage to any component for modern equipments?