I've updated the presentation on my website covering hum and noise issues. This deals with single ended interconnect systems, but you will also get some benefit if you use balanced interconnects.
Ground Loops
Ground Loops
Thanks!
It took me a minute to find the article- the link is:
http://hifisonix.com/wordpress/wp-content/uploads/2019/02/Ground-Loops.pdf
It took me a minute to find the article- the link is:
http://hifisonix.com/wordpress/wp-content/uploads/2019/02/Ground-Loops.pdf
Hi All,
One technique that I now stick to rigidly, particularly for low-level signal test equipment, is to put the mains transformer, rectifier diodes and initial smoothing caps (but no regulator) in their own metal external case that is bolted to the mains safety earth and not connected zero volts.
I then use an umbilical cable to the equipment case proper where it connects to the power supply/regulator.
I float the euipment case (which is also lined with screening mesh) and have a grounding lug connected to it. I then connect 0V to a 4mm post so I can bind the case and 0V explicitly at one point. If necessary I can also bring a mains earth to the ground lug from a main interference unit (I do a lot of low level measurements and heavily filter the mains to keep the mains-borne rubbish out)
This has always given me good results and flexibility whilst maintaining safety.
Regards
Mike
One technique that I now stick to rigidly, particularly for low-level signal test equipment, is to put the mains transformer, rectifier diodes and initial smoothing caps (but no regulator) in their own metal external case that is bolted to the mains safety earth and not connected zero volts.
I then use an umbilical cable to the equipment case proper where it connects to the power supply/regulator.
I float the euipment case (which is also lined with screening mesh) and have a grounding lug connected to it. I then connect 0V to a 4mm post so I can bind the case and 0V explicitly at one point. If necessary I can also bring a mains earth to the ground lug from a main interference unit (I do a lot of low level measurements and heavily filter the mains to keep the mains-borne rubbish out)
This has always given me good results and flexibility whilst maintaining safety.
Regards
Mike
Mike-
I don't understand...your 'equipment' case is not necessarily connected to the 'mains earth' (aka AC safety ground)?
It's not a big deal if you have only low-voltage solid state circuits inside, I suppose, but not a good idea with higher voltage (tube) gear.
Also, I think that residential wiring is 'different' in the UK from our standards in N. America, so that can affect what is considered safe.
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