I fully agree with AKG. If there is any way you can upgrade the feed from your panel to the wall socket, you will gain immense sonic improvement at all your equipment. I had a Rega Osiris too. I had a lot of mechanical hum out of the toroid coils coming from my dirty power. I installed a 1/2" emt conduit with 10AWG solid wire from my panel to a metal box with Porter Port receptacles in the wall. OMG. Everything jumped in performance. Some much more bass, clarity, immediacy in attack. Everything was better. But, I still had hum from the DC offset on the lines.
I then bought an Isotec Syncro cable. The one with the huge barrel which I assume is a Capacitor in line. That took all the hum out of the toroid coils. It even smoothed a little of the hash of the top end of the Osiris. It made the whole thing better.
However, I moved onto a Conrad Johnson Premier 140 amp with the Teflon upgrade. The Isotek took the hum out of that amp too. However it clouded that amp too much. Put a veil over the music. I then bought a Topaz 2.4 KVA line isolation transformer. I installed that in the basement inline with another 1/2" conduit and 10 AWG wire. This cut most all the hash out of the CJ amp and did very little to veil the music. However my First Sound Mark 3, Allnic HC1201 did not like it. They want pure unfiltered power.
In short, if you can better your power from standard 12AWG romex in the wall to metal enclosed 10AWG you will gain a huge jump in performance. A day of labor is about $500, materials about $250. Provided there is access from the panel to your gear. Now every change in power cables will be much more noticeable. I have a mix of Signal Cable, Cullen and Sillnote. They are all decent for the money.
