Following on from Chris's (and others) comments, I spend about £15 on Cat 6 UTP cable and 10 large ferrite chokes, mostly now fitted. I had already installed loads of smaller ones.
Very surprised about the result and it took some time to assimilate in my old brain. The initial impression was that I had lost the ambience in the recording, by that I mean the echo quality-well, you know what I mean. This had been present in most music, from stored digital or high quality internet radio, but was mostly absent now.
I realised though that the quality of the reproduction was better in other respects- vocals had more presence, there was a crispness to the sound and a better sense of where instruments were positioned including depth.
So the ambience that I had enjoyed for years is, by enlarge, not supposed to be there? At the moment, apart from feeling slightly stupid, I think that I have gained from the accuracy of reproduction but lost an old friend in the artifical ambience.
Jerry
Hifi: IPL transmission line floorstanding speakers, Squeezebox Touch, Denafrips Ares 11 DAC, DCB1 Pre-amplifier, Croft Series 7 power amp.
Custom Hifi cables HA10SE headphone amplifier and Hifiman HE-400 headphones.
AV system: LG 55B7, Denon AVR -x2300w receiver, Quad 12L (front) 11c Centre and 11L rear . Velodyne DD15 subwoofer.