In the beginning and for quite some time all my efforts were with speaker cables. Power cords and interconnects were routed away from each other, but with no attempt at isolation.
Until one day I had all these extra speaker cable elevators laying around and thought, what about power cords? Much to my surprise the improvement was almost as great as under speaker cables.
One day looking at my turntable, the phono leads going down to the gain stage touch the rack at both ends. Surely whatever vibration is in the rack winds up transmitting along the lead into the arm and this can't be good. So I rigged up a way to suspend the phono leads at both ends. Very nice improvement!
My friend in Belgium with a killer Magico Q7 system tried this, was floored at the improvement.
Gradually over time my whole system has been isolated and floats like this. Power cords, even the ones going to subs, benefit about as much as anything. This I find odd, because suspending the 3 power cords going to my subs seems to make an even bigger difference than the power cords themselves! The only thing I can think of is, without isolation they wind up feeding vibrations into the conditioner and everything else, just like the phono leads into the arm.
Isolation is so important, it even predominates with the power cord going into the motor pod of my Sovereign turntable. I've upgraded turntable motor power cords before, always with a nice result. But was disappointed with the Sovereign. Odd, since the power cord being used was a lot better than anything I had done this with before. I could only surmise maybe because it is so stiff?
So after a few failed experiments I thought well if isolation is so important maybe instead of all this crazy good expensive wire that is thick and stiff how about try cheap hook up wire that is soft and flexible? Just for the last few inches into the motor.
I soldered this to a spare IEC and connected a Synergistic power cord. Success! Isolation uber alles!