Hello,
Currently it seems necessary to plug/unplug headphones/speakers when wanting to switch between them.
Since PC case is under 110 volts for ungrounded PCs this creates potential for damages to systems.
Therefore audio systems should be designed to switch between headphones and speakers without having to re-plug anything.
I am not sure if my receiver can do it for example, but I am pretty sure my soundblaster can't do it, without a replug ;)
Bye, Skybuck.