The issue is getting clean power from the pole. I am not sure what this Equtech power system is, but unless it is a filter and conditioner, then you can benefit from having such a device chose to your components. The reason being that you are not getting clean power from the pole. You are sharing those power lines with all your neighbors, and with all the machinery within your own house. Air conditioning, refrigerators, and especially computerized equipment makes a lot of noise on the line. When they cut on and off it creates large spikes in voltage, up and down, there are just thousands of noise an spike causing devices between you and he power company. So it becomes necessary to use a filter or conditioner to convert that noisy electricity into something you would want to feed your stereo. If you know an electrician that has one of those hand held oscilloscopes, he can easily show you all of the noise that is coming in off the pole, and depending on where you live it can be quite shocking (pun intended) to see all the noise coming into your house, and being created therein.
I suggest you read this.
Here is another worth reading.
Click onto the right hand side of,
"Power Distribution and Grounding of Audio, Video and Telecommunications Equipment White Paper" (986 KB)
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?)
Yes I have experimented and all my digital is isolated from my analog. I believe it is better but it was installed this way so there was no comparison.
The power coming from most poles is anything but clean. I use industrial isolation transformers and constant voltage transformers, and they are superior to anything made for audio (anything which I have tried, that is). But, as Cox points out, they growl, so they must be installed outside the music room.
Coxhaus you've got a great setup. I'm sure your one of the few to hear a guitar sing from a digital drive. The isolation should be mandatory-well it is for great sound anyway. I agree with Terry-there is no such thing as clean power from the pole, anywhere. Terry, have you found it better to have the voltage transformers ahead of the isolation transformers, or vice versa?
The power system would be great for filtering out external noise from the power grid. The power conditioner/distibution system would be for isolating your components from one another. Both are potentially useful.
You also want a dedicated run for you listening room only. This reduces "in-home generated noise" contaminaion of your audio-video room.
Every electronic device you use contaminates the mains; your amps dumps noise into the mains that your DAC and pre-amp must consume. They in turn do the same.
Best is to have at least one form of conditioner per audio component. Needn't be an expensive boutique gear. A capacitor-inductor-capacitor filter for each device works magic and makes a huuuuge difference.
I put the isolation transformers nearer the pole. Also, they have at least twice the capacity of the CVTs which they drive.
I'm with you Pauly. Terry, have you tried reversing the order?
No - they cost too much. I like to use 2x headroom, so use the more expensive component last.