I just got a Dynahi and the amp makes a pretty loud sound when it turns off. Can this damage the headphones?

The other option is to unplug the headphones and short the amp to ground, which can only be a terrible idea on an amp this powerful.

Edited February 10, 201511 yr by dreamwhisper

There is a very simple solution that I use for my amplifiers: 1 resistor, equivalent to the headphones impedance, for each channel and a switch. The switch derives the output to the headphones or to ground, but through the resistor. In this way is possible to plug or unplug the headphones without any problem and the amplifier has the same load.

Edited February 10, 201511 yr by Remolon

unlike a lot of amps, the dynahi will work into a dead short if necessary

but if you want, build and install the protector board