The compressor in my setup has one important function: the option for making the sound of the voice more “present”. It is only used for compressing the clean microphone signal (coming from direct out 1-4 on the mixer), and it makes it possible to put “small” sounds, like whispering or talking with a low sound level, up front in the musical scenery. Furthermore, I sometimes use it for very loud passages where the voice sound needs more “power” in order to be heard. The settings for the compressor are normally not changed during a performance, only the level on the return channel, so the usability is not an important issue here. The challenge involved in using a compressor live on stage is of course to avoid compressing the instruments around me.
 My compressor was actually built for me by Ståle Storløkken. It is a “homemade” clone of an SSL Compressor.