I have a Sennheiser PC 360 headset that has volume control integrated into the right ear cup. I also have a Fiio E9 external amp (for my MacBook Pro), and my desktop has a Xonar Essence STX. My question is, which is better to control volume with? I've just been setting the PC 360 to half volume and then using the STX or e9 to control volume, as I figure a dedicated amp would do a better job.
Is this the right way to do it, or could I be doing something better?