Yes, most if not all. Yet another HDMI, Wi-Fi, or Ethernet connected device that brings no problems plugged into a Class II AVR.
"Most" people are now streaming Amazon, Netflix, etc. right from their smart TVs in fact right into their AV receiver via HDMI ARC.
I have not come across a single friend, neighbor, or co-worker in the past 10 years asking for help with a ground loop in their home AV system. The only two groups of people using analog unbalanced audio connections are audiophiles and normal people with really old equipment.
I am aware that this doesn't stop all interchassis currents (although wireless sources sure do
), but they don't become the same level of problem as when connecting two Class I devices with a standard RCA connection.
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Uh huh. I have about the smartest TV on the planet. The latest and greatest, as they would say. Somewhere that Netflix signal gets into your home... commonly via a coax (some lucky ones might be F.O.) via your cable provider.
That cable system is connected to earth ground and not necessarily to the same earth ground as power. New laws require it but if your home is not made recently, chances are the cable signal for internet is grounded where ever the cable enters the home. And not at the power utility box.
Thus, when two systems are connected together. a ground current loop is created.
Not that there are not solutions, because there are but maybe we should talk about it.
here we see the resulting current flow of two separate grounds.... between CATV cable grounding and utility power ground (wall outlet)
from being physically grounded outside the house at two different earth ground locations.
The solution was to cap couple the shield for RF only to pass.
THx-RNMarsh
That cable system is connected to earth ground and not necessarily to the same earth ground as power. New laws require it but if your home is not made recently, chances are the cable signal for internet is grounded where ever the cable enters the home. And not at the power utility box.
Thus, when two systems are connected together. a ground current loop is created.
Not that there are not solutions, because there are but maybe we should talk about it.
here we see the resulting current flow of two separate grounds.... between CATV cable grounding and utility power ground (wall outlet)
from being physically grounded outside the house at two different earth ground locations.
The solution was to cap couple the shield for RF only to pass.
THx-RNMarsh
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Hmm they are (finally) running fibre down our road. So does that mean that, if I have fibre all the way in my streamed music will sound better?
How would I know. you are there. measure or listen. do you use an LP/phono pre/pre-pre?
Depends on your particular grounding and A-V system.
Some might benefit, if not you.
I know from mass merchandise retail chains and custom home A-V install builders, it is a big issue.
'Your mileage my vary'
-RM
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Probably not. These things often become clearer after long years of experience with issues, falling on your face and finding working solutions. As they say, if you have to ask the question, you probably will not understand the answer
Edit: your multimeter probably looks like the attached
Jan
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Well we have never had cable here (cable is very patchy in UK). TBH I'm sidestepping most of the grounding problems by battery powering as much as possible. When current round of upgrades is complete only the power amps will need PE. As I have a miniDSP in the middle I may end up with the ADC in the preamp.
But I have no hum issues at the moment so not expecting any improvement, just a WAF improving reduction in the number of boxes
But I have no hum issues at the moment so not expecting any improvement, just a WAF improving reduction in the number of boxes
More cap stuff....
These are plots from around 1989 and 1990. I was developing an ultra fast cap, high current cap as I was working around high speed cap discharge banks. Wasnt intended for audio, BUT ...
They are current plots from discharging a PP film & foil cap charged to DC 5v into itself. The scale is 4A/div. 1.0 ufd/600v (1/24/1990)
Note the nice damped sine wave decay. The freq of ringing and rate of decay I used to collaborate the Fr of the cap and the peak current related to total esr.
Here we have a film cap also (same C value and voltage rating) ..... The waveform isnt a clean sine wave.
Notes on back of plot say --- FFT of distortion products, rectangular window. power spectrum.
and same as first cap except it is criticslly damped. 4A/div etc
THx-RNMarsh
These are plots from around 1989 and 1990. I was developing an ultra fast cap, high current cap as I was working around high speed cap discharge banks. Wasnt intended for audio, BUT ...
They are current plots from discharging a PP film & foil cap charged to DC 5v into itself. The scale is 4A/div. 1.0 ufd/600v (1/24/1990)
Note the nice damped sine wave decay. The freq of ringing and rate of decay I used to collaborate the Fr of the cap and the peak current related to total esr.
Here we have a film cap also (same C value and voltage rating) ..... The waveform isnt a clean sine wave.
Notes on back of plot say --- FFT of distortion products, rectangular window. power spectrum.
and same as first cap except it is criticslly damped. 4A/div etc
THx-RNMarsh
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Hmm they are (finally) running fibre down our road. So does that mean that, if I have fibre all the way in my streamed music will sound better?
Could be as you don't have to drag another dirty ground into the picture
//
Broken ? Not totally. The first improvement i found (long time ago) was to bridge the rectifiers on my amps from 1 to 2 (see attached 1). After this, did what i exlained. But it is not intellectually totally satisfying.
gpapag, thanks a lot. I will analyse-it. As habit, bcarso has clever ideas and is a master about HF and interconnections.
i dont think you understood the issue.
May-I try to explain ?
It is not electro-magnetic coupling between the AC lines and the signal ones. Good shielding and a good way (see attachment2) to connect the signal lines take care of this. I found CAT6 cables very good and cheap enough.
There is leakeage in the transformers, between primary and ground (secondary). By the capacitances between primary and secondary coils.
As no transformer between different devices are exactly the same, this leakage differ both on phase and amplitude, depending on the frequencies. This create voltages between grounds, and those voltages, despite the high frequencies, create a current. This brings to the input parasitic HF components (AC is full of shi...)
You dont hear-it during silences, like hum or buzz, with a good system, but it create IM dynamically with the signal.more or less, depending of the amp's bandwidths. It is subtil, but audible: less transparency, less separation between instruments.
Free to you to make your own measurements. The first one is to measure the voltage, between the two grounds, and watch it with an oscillo once your two devices are AV powered, before to connect the signal between them.
Hoping this will help somebody.
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Even if you have a ground loop is that really causing a problem? I would like to see a setup that will induce hum on using an AV receiver connected to source devices via HDMI and outputting directly to the speakers. This is the common "normal person" setup.
With regard to Netflix, your TV gets that data over either a wired ethernet connection which is transformer coupled, or Wi-Fi which is wireless obviously. There doesn't have to be any galvanic connection to your cable system.
geez. just that one does not usually include the parasitics of a given cap to be used in their circuitry. [Though it is common in RF.]
You can measure the parasitic of the particular cap and then put those into a cap model of each one used in the over-all design.
THx-RNMarsh
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I dont use a receiver for my main listening system nor video. You might be on the wrong forum? But if you do and use HDMI (not a great audio path), then maybe you are correct. i dont know.
Several of my audio gear separates have grounded ac power plugs (three prong). If via interconnects to any other video, computer chassis, modem etal and thier common connect to the audio there is a path to its ground thru video cable.... ground loop. Also, a common setup in USA.
But that is easy to deal with without resorting to using an HDMI reciever.
Just break the path. Use a HP filter in line with the video or anywhere in the loop to stop it.
THx-RNMarsh
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Context... you brought up AV systems and I told you what 99% of the world does.
If you don't use a AV receiver in a video system I am curious what you use? Separate surround processor like a Lexicon? It's hard to decode DTS-MA, Dolby Atmos, etc. otherwise.
I understand what a ground loop is. Which is why I avoid unbalanced connections between two Class I appliances.
Why do you think HDMI not a good audio path? It's not ideal maybe because the clock comes from the source, but it is possible to design a component capable of realizing the full performance of any commercially available DAC IC at the analog outputs with an HDMI input. Not any different than SPDIF.
If you don't use a AV receiver in a video system I am curious what you use? Separate surround processor like a Lexicon? It's hard to decode DTS-MA, Dolby Atmos, etc. otherwise.
I understand what a ground loop is. Which is why I avoid unbalanced connections between two Class I appliances.
Why do you think HDMI not a good audio path? It's not ideal maybe because the clock comes from the source, but it is possible to design a component capable of realizing the full performance of any commercially available DAC IC at the analog outputs with an HDMI input. Not any different than SPDIF.
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my mistake, I thought this was JC forum on high-end audio design? You know, One percenters?
yes, separate decoder..
-RNM
No,it isn't, this is Darry's thread who wanted precise information for his amplifier archive 12 years ago. He didn't get very far even after 120000 posts. What he got was a lot of hot air and gossip with occasional highlights when the thread turns really off topic.
But at least it seems, that Darry was still alive a year ago.
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