So! My hum is history!
I had a feeling all along that it was a ground loop but had no way of defeating it because everything was plugged into the same strip.
Whilst I was waiting for PL and the dealer to come back I saw something in the local hifi store and thought “fuck it, let’s give it a go, if it doesn’t work I can always return it”
I bought 2 of these ifi silent power gnd defenders. They plug into your IEC port on the gear and then the power cable plugs into them. They supposedly drop the ground if they notice a loop, whilst keeping a safety ground, but do nothing if there is no ground loop.
The optimum configuration for each system is one Ground/Earth for the whole system. If a system has multiple Grounds/Earths, then it often creates unwanted ground loops. These systems will then have an annoying low-frequency hum (emitted from the speakers). Current solutions either jeopardise...
ifi-audio.com
Whilst not cheap at €100 each they have worked perfectly for me and are relatively speaking not that much when you consider they have killed the hum between a €1800 pre amp and €4000 power amp!
They also launched D.C. blocker in the same line which filters out any D.C. on the AC which is great for any gear where you have a beast of a transformer that’s physically humming/vibrating.
Got big amplifier. Bye bye mechanical hum. Many large amplifiers have a really annoying mechanical hum (emitted from the toroidal transformer itself). You can hear it when you place your ear close or next to the chassis. This is caused by a small amount of DC voltage in the mains which makes its...
ifi-audio.com