Obviously one of my interests is stereos. Particularly vintage solid state. Though I do have some tube gear. A few items are posted in my profile

Other hobby interests are:
electronics in general
vintage computing (I have a running DEC VAXstation and PDP-8/e)
MGB
Lionel model trains
ham radio

Professional interests
BS EE
MS CS
post graduate work in EE
Smart Grid (intersection of Power Engineering and Internet of Things) and the related cyber security aspects of that