You're not hearing things Gary . The improvements which you have described above have been my experience too . I've been playing around with mains cables for years now and wouldn't be without mine . Make sure you have the following . A good quality unswitched socket . MK Logic or Crabtree . A good quality mains block if you need one , and good quality mains cable and plugs . This Belden mains cable is excellent VFM
https://www.ebay.co.uk/itm/BELDEN-19...kAAOxyJX1TDRbU . If you want to upgrade contact David Brook at MCRU . He'll let you try some very nice cables . He's a very helpful guy .
Above all , use your own ears . If you hear an improvement , then it's an improvement . Your ears , your system , your music :)