Need for Power Conditioning??

To get a preliminary idea how less contaminated electricity "sounds" in your system, try inexpensive Machina Dynamica Flying Saucers for insertion into the unused AC wall sockets of your listening room and other rooms.
Together with Mapleshade Records power strip/power conditioner there is clearly audible improvement or optimizing of system performance, even without pursuing more expensive and extensive fixes.
For me, this is a major contribution to what is needed.

You must experiment. If you have a resolving system that's properly wired you will notice a distinct benefit merely by adding additional separate isolation for your digital on top of your overall isolation with your Equitech. (I hope you have a phase reverse switch on your preamp -or- ensure proper phase to your loudspeaker by switching your black and red connections which reverses phase to the speakers. When playing in correct phase the music will sound cleaner, smoother, more dynamic and sibilants will be reduced.) When you used to clean power you won't want to go back; likewise with correct phase.

If you are building a music room, you will want built in power conditioning. Have it designed into the room. This is your opportunity to install a large unit to condition all your music room plugs. These big units hum and will need to be located other than in the music room. They will be hard wired into your electrical system. After having done this I will never go back. The sound is so much better.

As well, look into/read up about doing your AC wiring using good quality well shielded wire as is used in sensitive and critical computer controlled robotic applications. It's vastly superior to basic household or even standard industrial 10 gauge wire. Much more resistant to noise. I accept what Coxhaus says above; however, he to will find further improvement by adding additional conditioning to his digital, analog or both. The more revealing the system the more benefit you enjoy from these efforts. (Have you experimented Coxhaus?)