I have a similar hum, only with lower impedance higher sensitivity phones that does not change with respect to the volume knob and am looking for advice as well.
I'm sure you can implement that source switcher if you don't mind your input going through that switch.
I haven't measured my temperature, but more ventilation holes would never hurt!
I noticed that snap when powering down, I take it safe and remove the headphones when powering down or up.
Lastly, any comments on this mod?
http://www.head-fi.org/forums/6171572-post50.html
I'm sure you can implement that source switcher if you don't mind your input going through that switch.
I haven't measured my temperature, but more ventilation holes would never hurt!
I noticed that snap when powering down, I take it safe and remove the headphones when powering down or up.
Lastly, any comments on this mod?
http://www.head-fi.org/forums/6171572-post50.html