Yeah, next time you board a plane look into the cockpit. A lot of complex electronics in there! Look at all the fancy display screens and consider the computers that drive them. Then think about all the microvolt range analog sensors that feed into those computers.
Where's the earth ground?
True but PE sometimes is connected straight to audio GND in some areas which is not the most optimal in audio. So the audio GND which normally is connected to the secondary connection of a transformer is connected to PE. I am a sinner here as I never connect audio GND to PE but of course I do connect chassis to PE. After many hum problems and professional experience I think I understand something of PE. Mains filters may be beneficial in some areas but if needed better use a ready built and tested one. I do measure mains voltage and currents and some areas are loaded with RF garbage on power lines. LED drivers, SMPS, cell phone transmitters , industrial power users etc. may pollute the mains more than one would like. Somewhere in the eighties I noticed my then analog HiFi equipment to sound better at night. This had a reason, mains voltage was way cleaner at night (then). Mains filters can do good in such cases.
BTW any DIYer should be aware how to use PE correctly. If it is not in your benefit then it is in your families benefit.
It's "TT" here! Safe and clean!
That is an assumption. Suppose the earthing rod to be corroded. Big drawback of the TT system.
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Proper audio "grounding" is a very complex thing. Sure there are times when HLB is a good idea, I think it can be done perfectly safely, some don't
It's not the Protective Earth that's connected to the dirt/soil. The stake in the garden is connected to the Neutral. But it's not part of your home's Protective Earth system.
Yes that's why the Protective Earth needs to be connected to the Neutral inside your home.
I remember back in the 80's being teenager - allways TT system - houses' central panels were only holding fuses! I mean the ceramic thing with the thin wire in it. I used to fill a glass of water, add salt and sink in a stripped power cord coming directly from the mains outlet.
There was a shiny sparkle like a mini star on the live conductor and a rattle shaking the glass that could continue as long as it was left... After a few minutes the water was turning blue. By no means recomended but anyway, it cannot be done nowdays. The protection devices would be triggered instantly!
Another thing that could be helpful; I' ve built the Lampizator's filter. It was back in the days I didn't understand how it works and I took it as a ready recipe. I used X and Y capacitors and ommited the ground switch and I recomend no deviations from this. As I became to understand things a little better, I made some changes. I removed the ground coil as it does nothing usefull in a TT system and I wounded the torroid coils differently because I think the original are not common mode (?) See attachment. Also, I added a DC offset blocker which is mandatory for my big torroid PTs. Does it do anything? A minor change which I frankly believe it comes from the first capacitor and only this. The rest I don't think it functions. I use a method to measure coils with ARTA. Coils with very low DCR can be measured and I' ve verified accuracy down to 0,1 mH not saying that it doesn't go lower. The filter's coils are below 100μH. Perhaps not an accurate measurment but certainly way below the mH region that is needed to reach down to 100kHz. The original design should go above RF.
There was a shiny sparkle like a mini star on the live conductor and a rattle shaking the glass that could continue as long as it was left... After a few minutes the water was turning blue. By no means recomended but anyway, it cannot be done nowdays. The protection devices would be triggered instantly!Another thing that could be helpful; I' ve built the Lampizator's filter. It was back in the days I didn't understand how it works and I took it as a ready recipe. I used X and Y capacitors and ommited the ground switch and I recomend no deviations from this. As I became to understand things a little better, I made some changes. I removed the ground coil as it does nothing usefull in a TT system and I wounded the torroid coils differently because I think the original are not common mode (?) See attachment. Also, I added a DC offset blocker which is mandatory for my big torroid PTs. Does it do anything? A minor change which I frankly believe it comes from the first capacitor and only this. The rest I don't think it functions. I use a method to measure coils with ARTA. Coils with very low DCR can be measured and I' ve verified accuracy down to 0,1 mH not saying that it doesn't go lower. The filter's coils are below 100μH. Perhaps not an accurate measurment but certainly way below the mH region that is needed to reach down to 100kHz. The original design should go above RF.
Attachments
I was thinking to replace the whole thing with IEC build in filters but perhaps I'll try JPS64's scheme. The box allready includes the DC offset blocker I need and it serves as a seven outlet power strip.
Thanks for the schematic! The led is a mains phase indicator. If the plug is wrong the led is "on". If it's pluged right the led is "off". But please disregard it. After installing this to all my gear, I witnessed diodes shortcircuit failures fortunately taking with them only the PT primary fuse. Also I suspect bad interaction with my audio PC ATX psu. I now use an empty panel fuse holder connected only with one IEC inlet's conductor. This provides an easy access to a mains tester.
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