Observation on earth loop
I recently divorced the 15" driver from the main amp on my system to run it with its own amp, dsp and passive volume using paralleled speaker output from the main amp and voltage divider to knock it back to line level. This involved hunting round the house for spare interconnects to link the four components and I cobbled them together with cables as diverse as freebies and Audionote solid silver. It was no real surprise that there was an earth loop issue which the 15" driver revealed to the point of annoyance.
By pure coincidence I bought a number of Klotz 5000 cables from this site. They had earthed screen which to quote a song by Shania "that don't impress me much". Well I installed them without any great expectation primarily just to harmonise the cables.
The earth hum disappeared.
Source
SW1X Universal Music Server UMS I Signature with Power Supply Unit PSU I Signature
SW1X USB II
SW1X DAC III Special
Audiolab 6000 CDT transport
Amps
Pre amps -- Hi fi Collective twin mono ladder stepped attenuator, with Charcroft Z-foil and silver wired. And First Watt B1 active no gain buffer.
Power amps -- Welborne 45 SET monoblocks 1.8W / Decware Taboo 6W / Elekit 300B TU-8600SVK plus further improved components 9W / ICE Power 1000W
Speakers
Highly modified Endorphin P17 open baffle speakers containing both vintage and modern alnico drivers and paper cones. All silver wired - 8" Cube Audio FC8 full range drivers and vintage 15" Altec VOTT 416 bass drivers. All sat on Townsend Audio Podium seismic isolation platforms.
BK Electronics XLS400FF Sub.
Cabling
Silver mains cables, interconnects and speaker cables by SW1X
Headphones
HRT HeadStreamer and SennHeiser HD650 headphones