new equipment power conditioner or more powerful amp?

I 2nd-3rd-4th the ideas of room treatment and a dedicated line.
Check out ATS Acoustics online if your wish to DIY room treatments. Not difficult to make room absorption panels and relatively inexpensive.

Lots of info on both topics herein on this forum.

I believe in quality of power, not quantity. Not likely you need a new amp, considering power only.