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This audio cable business is getting out of hand...

ajawamnet

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Measuring your homes earthing resistance, electrocuting people, measuring power supply emissions in a super high tech secret military lab.....
Wow! You guys sure know how to have a good time!

I thought that hanging around with much younger women from California in hot tubs was fun, but it got old much faster than you'd think.

My life needs a major rethink.

Wait - hot tubs? Hot Babes? Huh? I'll try that for a while... 'til my wife kills me.
albundy2.jpg
 

ajawamnet

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Sure, but as I wrote, that is for lighting protection and static electricity. There is a separate neutral/earth return all the way to your transformer/distribution station. In any case it doesn't matter for audio - as long as there is a common "neutral" point, the absolute potential of it doesn't matter. Voltage is the potential difference between two points, not the potential between a point and some universal reference.

There was one story as to grounding that occurred years ago when I was the bench tech at Opus One in Pgh. I recall a KA-7X coming down the lift that was picking up Radio Moscow (what was on the repair ticket) on the MC preamp. I went to Phil ( the tall sales guy that wrote the ticket) with a WT#$%@ and he mentioned that the guy ran the electron microscope at CMU . Sure enough after going to the guy's place I noticed he had a DX antenna with the lightning protection (that was all corroded) tied to the same ground as his stereo (Thorens with a Supex). And yea he was getting shortwave into his system at dusk when the ionization of the atmosphere changed - a common issue with longer wavelength RF.

For instance, AM stations that are not clear channels have to change power as to the time of year and time of day.
https://www.fcc.gov/media/radio/am-stations-at-night
 
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As to power strips in the US - I noticed a lot of them are including a "Grounded" LED that actually injects a ground fault current on to the 3rd prong... I always look for the ones that don't have this feature - even in non-audio applications.
054732108855.jpg


With it off:
powerstripoff.jpg


With it on; meter in AC mA :
powerstripon.jpg


Schematic: http://www.ajawamnet.com/ajawam2/POWERSTRIP.pdf
typpwrstripwithgndindicator.png
 

LuckyLuke575

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Not true at all, that thinking is over 20 years old. Nowdays SMPS supplies are so well engineered they outperform linear supplies in every way - lower noise in all areas, lower output impedance etc etc. Jan Didden proved this with his Silent Switcher. Watch John Siau's discussion of cables from 8 mins where he shows that the Dac 2's switching supply is quieter than the Dac 1's linear PSU.
Posting videos like this should be classified as wire fraud
 

Wombat

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FWIW: Way back in my State Electricity Commission days I spent some time as the Safety Engineer. Electrocuted meant killed, otherwise the term used was 'received an electric shock".
I have no idea - I'll go with being killed... so he should have stated - "... zapped the hell outta ol' Ace..."

And Merriam Webster:

https://www.merriam-webster.com/dictionary/electrocute
to kill or severely injure by electric shock
Because of flawed electrical work by contractors, the bulletin stated, soldiers at U.S. bases in Iraq had received severe electrical shocks, and some had even been electrocuted.— James Risen

But if a power outage occurs, the PV [photovoltaic] system has to shut down or it could electrocute utility workers who think they're working on dead lines. — Popular Science

He was working on Pier 38 on the West Side of Manhattan when he was accidently electrocuted by a high-voltage wire. He suffered second- and third-degree burns and had to undergo painful skin grafts. — Robert I. Friedman


Interesting that the M/W webpage left accidentally misspelled in the quote... I guess they have to if it's attributed to someone. Dunno
 

trl

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As to power strips in the US - I noticed a lot of them are including a "Grounded" LED that actually injects a ground fault current on to the 3rd prong... I always look for the ones that don't have this feature - even in non-audio applications.
View attachment 38355

With it off:
View attachment 38356

With it on; meter in AC mA :
View attachment 38357

Schematic: http://www.ajawamnet.com/ajawam2/POWERSTRIP.pdf
View attachment 38358
I only see positive facts about that light connected to Earth:
- it's a safety light that will not light up if there is no grounding present to the power outlet;
- the 0.45mA is insignificant and the costs of electricity consumed is pretty close to zero;
- there should be no noise injected into the ground by that LED, although cheap 0.1...1uF X2-type abd 10...100pF Y2-type caps already exist in most audio equipment, to ensure a basic common-mode filtering;
- my 30mA RCCB/RCBO will trip faster now

From a safety reason I would recommend such lights. You never know when a power outlet has a faulty grounding.
 

Wombat

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I have no idea - I'll go with being killed... so he should have stated - "... zapped the hell outta ol' Ace..."

And Merriam Webster:

https://www.merriam-webster.com/dictionary/electrocute
to kill or severely injure by electric shock
Because of flawed electrical work by contractors, the bulletin stated, soldiers at U.S. bases in Iraq had received severe electrical shocks, and some had even been electrocuted.— James Risen

But if a power outage occurs, the PV [photovoltaic] system has to shut down or it could electrocute utility workers who think they're working on dead lines. — Popular Science

He was working on Pier 38 on the West Side of Manhattan when he was accidently electrocuted by a high-voltage wire. He suffered second- and third-degree burns and had to undergo painful skin grafts. — Robert I. Friedman

Interesting that the M/W webpage left accidentally misspelled in the quote... I guess they have to if it's attributed to someone. Dunno
Different usage in various countries, probably.
 

Sal1950

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"Electrocution" Cleanin up Ole Sparky as he's affectionately known at the Florida State Prison. ;)
 

solderdude

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I recall a KA-7X coming down the lift that was picking up Radio Moscow (what was on the repair ticket) on the MC preamp.
I had this problem as well on some days. The solution was simple in my case.
The reason this happens is because the MM coils and input capacitance formed a nice receiver with a rather high Q.
The transistors in the pre-amp could rectify (AM detect) that signal when it became high enough.
My solution was to put a 220 Ohm resistor in series with the input. This lowered the Q of the 'receiver' (MM coil + input capacitance) so much that it never reached detectable levels and so the result (AM detection) was solved.
 
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I only see positive facts about that light connected to Earth:
- it's a safety light that will not light up if there is no grounding present to the power outlet;
- the 0.45mA is insignificant and the costs of electricity consumed is pretty close to zero;
- there should be no noise injected into the ground by that LED, although cheap 0.1...1uF X2-type abd 10...100pF Y2-type caps already exist in most audio equipment, to ensure a basic common-mode filtering;
- my 30mA RCCB/RCBO will trip faster now

From a safety reason I would recommend such lights. You never know when a power outlet has a faulty grounding.

One of the problems - besides putting current on the safety ground that shouldn't be there - is that IF the ground DOES LIFT you'll get that LED/resistors connection on any metal that is on the appliance connected. Hopefully grandpa at the outdoor bingo in wet grass doesn't get nailed when touching the metal coffee maker... granted it's only 450uA but have enough of these strips plugged in and it can get into the mA's...

The other issues - this is cool - is if you plug enough of these into a GFCI circuit it will trip. Like say, in a garage that has to - by code - have GFCI's. That's how I found out about it.

What they should have is either an active circuit that actually detects the presence of ground, or at least a momentary pushbutton that can be used to test for the ground
 
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I had this problem as well on some days. The solution was simple in my case.
The reason this happens is because the MM coils and input capacitance formed a nice receiver with a rather high Q.
The transistors in the pre-amp could rectify (AM detect) that signal when it became high enough.
My solution was to put a 220 Ohm resistor in series with the input. This lowered the Q of the 'receiver' (MM coil + input capacitance) so much that it never reached detectable levels and so the result (AM detection) was solved.
Once he moved his system ground away from the outside long wire - and cleaned up the lightning protection on it - it all went away.
 
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"Electrocution" Cleanin up Ole Sparky as he's affectionately known at the Florida State Prison. ;)
Reminds me of the Robot Chicken with the Wizard of Oz episode with Scarecrow being executed - they copied that quite well:
woz.jpg
 

solderdude

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Once he moved his system ground away from the outside long wire - and cleaned up the lightning protection on it - it all went away.
Yes, same reason except in his case he had an extra antenna.
 

trl

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One of the problems - besides putting current on the safety ground that shouldn't be there - is that IF the ground DOES LIFT you'll get that LED/resistors connection on any metal that is on the appliance connected. Hopefully grandpa at the outdoor bingo in wet grass doesn't get nailed when touching the metal coffee maker... granted it's only 450uA but have enough of these strips plugged in and it can get into the mA's...

The other issues - this is cool - is if you plug enough of these into a GFCI circuit it will trip. Like say, in a garage that has to - by code - have GFCI's. That's how I found out about it.

What they should have is either an active circuit that actually detects the presence of ground, or at least a momentary pushbutton that can be used to test for the ground
I see your point, although RCCB/RCBO/RCD/GFCI will definitely trip when touching the outer case of an electronic appliance if your scenario will ever happen.

I guess the momentary push button would be the cheapest option after all, although like you said, an active circuit would be best. Thanks for sharing!
 
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