Grounding AV receiver

[manofsteel]

Bring it closer. RF interference is now a modern plague, with LED light bulbs, especially when connected to SCR light dimmers, produce huge amounts of RF.

Designers as a whole are not paying nearly enough attention to RF rejection in their designs.

I was reading on here that some people who have cable and satellite had problems with their cable and satellite spliters that needed grounding
Would this cause the hum even though they are not connected to the receiver but are connected to the TV and satellite box

 

[TLS Guy]

I was reading on here that some people who have cable and satellite had problems with their cable and satellite spliters that needed grounding
Would this cause the hum even though they are not connected to the receiver but are connected to the TV and satellite box

They certainly could if the TV is connected to your receiver, but not if the connection between your TV and receiver is disconnected.

If your satellite system is AT&T Direct TV, then their boxes are real junk, and have internal ground loops. But if there is no connection between that system and your receiver then will be NO hum, until you connect it up.

The other issue with satellite systems, is that there must be a grounding block going up to the dish, with it own ground. That is code, for lightning protection. However, unless you are really obsessional an bind that to your panel as well, with a massive cable, you will have a ground loop.

Basically satellite systems are a nightmare, and unless you really know what you are doing, will definitely give you a buzz!

You can not use ground isolators with satellite systems either, as the dish is phantom powered, and an isolator cuts the power to the receiver at the dish.

I went through all this at our former lake home. If you are into HT, satellite systems should be an absolute last resort.

 

[Hetfield]

I have hum on my HT and I have been trying to get rid of it for a long time. It's so annoying and I just basically gave up. I only hear it when I put my ear to a speaker but still annoys the hell out of me. I have tried cheater plugs, changing outlets, amp on a different outlet. I've just had it honestly.

Sent from my Pixel 4 XL using Tapatalk

 

[TLS Guy]

I have hum on my HT and I have been trying to get rid of it for a long time. It's so annoying and I just basically gave up. I only hear it when I put my ear to a speaker but still annoys the hell out of me. I have tried cheater plugs, changing outlets, amp on a different outlet. I've just had it honestly.

Sent from my Pixel 4 XL using Tapatalk

Well, that is probably just the hum from the receiver. Receivers do not have the greatest signal to noise specs, and they always quote weighted specs, to hide the fact as much as they can.

 

[Hetfield]

Well, that is probably just the hum from the receiver. Receivers do not have the greatest signal to noise specs, and they always quote weighted specs, to hide the fact as much as they can.

I think it's the external amp maybe, I have the Denon X3400H as basically the processor controlling a Parasound HCA1205A 5 channel amp. I tried a cheater plug for the amp and it's still there. I tried the amp on a second outlet. I tried a cheater plug on the power strip itself. I moved everything away from where the WiFi router is located and it's still there. It's so annoying and truly pisses me off to no end.

Sent from my Pixel 4 XL using Tapatalk

 

[TLS Guy]

I think it's the external amp maybe, I have the Denon X3400H as basically the processor controlling a Parasound HCA1205A 5 channel amp. I tried a cheater plug for the amp and it's still there. I tried the amp on a second outlet. I tried a cheater plug on the power strip itself. I moved everything away from where the WiFi router is located and it's still there. It's so annoying and truly pisses me off to no end.

Sent from my Pixel 4 XL using Tapatalk

Well that is easy to tell. Just leave the Parasound connected to the speakers and disconnect it from the Denon. Any hum you hear then is coming from the Parasound.
How old is it? It might need new power supply caps, if the hum is excessive. However putting your ear up to a speaker is not considered excessive. Excessive is when you can hear it at the listening position in a dead quiet room.

 

[Hetfield]

Well that is easy to tell. Just leave the Parasound connected to the speakers and disconnect it from the Denon. Any hum you hear then is coming from the Parasound.
How old is it? It might need new power supply caps, if the hum is excessive. However putting your ear up to a speaker is not considered excessive. Excessive is when you can hear it at the listening position in a dead quiet room.

It's pretty old, 20 years probably? And I never thought of that. Parasound when I emailed them said something about caps might not to be replaced at some point. I don't even know what the is? Capacitors? That sounds like a hassle and not something I can do myself. The hum I don't hear till I put my ear to the speakers, and it's all of them. It still pisses me off to no end and just effect the sound in some way I'd think.

Sent from my Pixel 4 XL using Tapatalk

 

[TLS Guy]

It's pretty old, 20 years probably? And I never thought of that. Parasound when I emailed them said something about caps might not to be replaced at some point. I don't even know what the is? Capacitors? That sounds like a hassle and not something I can do myself. The hum I don't hear till I put my ear to the speakers, and it's all of them. It still pisses me off to no end and just effect the sound in some way I'd think.

Sent from my Pixel 4 XL using Tapatalk

It takes an exceptional power amp, not to hear a little hum if you put your ear right in a speaker. That is nothing to be concerned about, and it will not affect the sound, if you can't hear it at the listening position.

 

[Hetfield]

It takes an exceptional power amp, not to hear a little hum if you put your ear right in a speaker. That is nothing to be concerned about, and it will not affect the sound, if you can't hear it at the listening position.

Oh wow, I had no idea. That's interesting info then. I thought it was a huge problem and issue. I definitely can't hear it during a movie or listening to music.

Sent from my Pixel 4 XL using Tapatalk

 

[manofsteel]

They certainly could if the TV is connected to your receiver, but not if the connection between your TV and receiver is disconnected.

If your satellite system is AT&T Direct TV, then their boxes are real junk, and have internal ground loops. But if there is no connection between that system and your receiver then will be NO hum, until you connect it up.

The other issue with satellite systems, is that there must be a grounding block going up to the dish, with it own ground. That is code, for lightning protection. However, unless you are really obsessional an bind that to your panel as well, with a massive cable, you will have a ground loop.

Basically satellite systems are a nightmare, and unless you really know what you are doing, will definitely give you a buzz!

You can not use ground isolators with satellite systems either, as the dish is phantom powered, and an isolator cuts the power to the receiver at the dish.

I went through all this at our former lake home. If you are into HT, satellite systems should be an absolute last resort.

Thanks for the reply
So I moved the subwoofer closer to the receiver and used a shorter lfe cable. Didn't make a diffirence
The satellite dish was here when I moved in. Don't see see any ground box unless it's near the dish on the roof
The hum seems constant hum
If I lift ground on the power lead going to the subwoofer the hum goes very feint
If I use a ground loop isolator with no ground lifted the hum goes away completely

The subwoofer is a rel qbass
Do you think it could be failing caps
There are no visual signs of failing caps

 

[highfigh]

RCA cables are 75 ohm the same as RCA, but the capacitance is different, so this I suppose could be an issue. Either way, move the sub close to the receiver and connect it with a short good quality RCA cable.

No- RG6 in various brands and shielding schemes have been used for literally hundreds of thousands of applications for audio, if not millions and it works unless the terminations are bad, a ground loop exists, someone damaged it or something like using a ungrounded power cord on a device that needs to be grounded, the building's wiring is flakey, etc.

 

[highfigh]

One thing I've tried that helped as a test is removing the earth from the kettle lead to power the subwoofer. The hum was very low. Not so loud
Also I tried a ground loop isolator and that got rid of the hum but the volume output quality really low

What is a kettle lead? DO NOT do that.

How old is the building, when was the electrical service worked on and was it done properly/up to code? Were the outlets 'back-stabbed? NEVER back-stab outlets.

 

[TLS Guy]

Thanks for the reply
So I moved the subwoofer closer to the receiver and used a shorter lfe cable. Didn't make a diffirence
The satellite dish was here when I moved in. Don't see see any ground box unless it's near the dish on the roof
The hum seems constant hum
If I lift ground on the power lead going to the subwoofer the hum goes very feint
If I use a ground loop isolator with no ground lifted the hum goes away completely

The subwoofer is a rel qbass
Do you think it could be failing caps
There are no visual signs of failing caps

Either you have a ground you have forgotten about, or you have a receptacle with the live and neutral reversed. Use a multimeter, or by a tester at home depot, that will tell you if you have a receptacle wrongly wired.

Something is not right. If you truly only have one ground, you can't have loop, it takes are circle to make a loop. It is not failing caps, or it would hum whatever you do.

The fact the ground loop isolator stops the hum completely, makes me think there is a ground you have missed and forgotten about.

Hi-Fi might be onto something. I wonder if your house wiring is not to code and dangerous. For instance if the neutrals were not properly bonded to ground at the panel, then that would explain you problem also. If you are certain you do not have a ground you have not told us about, then your house wring needs checking from top to bottom by a professional.

 

[manofsteel]

Either you have a ground you have forgotten about, or you have a receptacle with the live and neutral reversed. Use a multimeter, or by a tester at home depot, that will tell you if you have a receptacle wrongly wired.

Something is not right. If you truly only have one ground, you can't have loop, it takes are circle to make a loop. It is not failing caps, or it would hum whatever you do.

The fact the ground loop isolator stops the hum completely, makes me think there is a ground you have missed and forgotten about.

Hi-Fi might be onto something. I wonder if your house wiring is not to code and dangerous. For instance if the neutrals were not properly bonded to ground at the panel, then that would explain you problem also. If you are certain you do not have a ground you have not told us about, then your house wring needs checking from top to bottom by a professional.

Hi
I've just had allot of wiring done recently .
I've connected another subwoofer that I borrowed. Although newer and I connected a wire from the chassis of subwoofer to ground and no hum. Although was plugged in different outlet
All I have connected is the subwoofer, the lfe cable and wire grounding subwoofer to av receiver
No hdmi

 

[manofsteel]

What is a kettle lead? DO NOT do that.

How old is the building, when was the electrical service worked on and was it done properly/up to code? Were the outlets 'back-stabbed? NEVER back-stab outlets.

Like I said the kettle lead and lifting ground was only a test. I used a RCD plug for the test

 

[lovinthehd]

LOL had to look it (kettle lead) up, it's a power cord for anyone else scratching their heads.....always with the tea....

 

[highfigh]

Like I said the kettle lead and lifting ground was only a test. I used a RCD plug for the test

You should have told us where you live- if 'kettle lead', which is far from a typical name for a power cord in the rest of the World, is actually the power cord, using common terminology will help you find a solution faster. It also tells someone that your electrical service isn't the same as it is in other places, we can't help as well as if it is.

If you're a Brit and moved to the US, the use of 'kettle lead' is now understandable, but more info up front would have helped. Now that we know you had electrical work done, we need to know if it was in the same area, if breakers were added and if your system is sharing circuits that were used for existing lighting, outlets, etc.

 

[lovinthehd]

You should have told us where you live- if 'kettle lead', which is far from a typical name for a power cord in the rest of the World, is actually the power cord, using common terminology will help you find a solution faster. It also tells someone that your electrical service isn't the same as it is in other places, we can't help as well as if it is.

If you're a Brit and moved to the US, the use of 'kettle lead' is now understandable, but more info up front would have helped. Now that we know you had electrical work done, we need to know if it was in the same area, if breakers were added and if your system is sharing circuits that were used for existing lighting, outlets, etc.

LOL but TLS had no issue understanding that one I'd think....

 

[manofsteel]

LOL but TLS had no issue understanding that one I'd think....

Sorry
If you asked me then i would have happily told you that I was in UK

 

[highfigh]

LOL but TLS had no issue understanding that one I'd think....

And he didn't mention it, either. Holding out on us, again.