Audio hum / buzz with analog audio but not HDMI...

[Nealio]

Hi guys, I just had DirecTV installed a few days ago and I am having a problem with when my old tube TV is hooked up to the receiver via analog audio. There is a constant hum / buzz sound that is extremely noticeable whenever there isn't much talking or music going on. I have recorded a short sample of changing the channels and put it on YouTube. Here is the link (note that I slightly amplified the audio so that you can easily hear it).

[ame=http://www.youtube.com/watch?v=a5KZ_VP6rlk]YouTube - Audio Hum / Buzz with Analog Audio[/ame]

What I find strange is that when I use the same receiver to hook up to my HDTV via HDMI, there is absolutely none of that noise. If I hook the analog cables to my HDTV, the noise is there again just like it was with my tube TV. Any ideas why the analog cables do this but the digital/HDMI cable doesn't?

 

[Davedirectv]

By analog audio I'm assuming you are talking about the red/white composite cables?

What it sounds like from that noise, is something is crossed.

Just to make sure, check that you have white into white and red into red, on both the box and the tv.

 

[Nealio]

Yeah, by analog I mean the RCA/composite red/white cables. I am away from home right now, but I'll double check that they aren't crossed later tonight. I'll even cross them to make sure something isn't labeled incorrectly or to see if there is some other problem.

Also worth nothing is that I have 2 receivers from Direct. About an hour ago I tested everything out on the 2nd one, and there is no noise whatsoever when it's hooked up with the same RCA cords that produce that noise on the other receiver. I even brought my computer to that TV to make a few recordings to see if there was any noise, and there was no noise on with it either. I might try switching around the receivers later tonight to see what happens.

 

[Jimbo]

Yeah, by analog I mean the RCA/composite red/white cables. I am away from home right now, but I'll double check that they aren't crossed later tonight. I'll even cross them to make sure something isn't labeled incorrectly or to see if there is some other problem.

Also worth nothing is that I have 2 receivers from Direct. About an hour ago I tested everything out on the 2nd one, and there is no noise whatsoever when it's hooked up with the same RCA cords that produce that noise on the other receiver. I even brought my computer to that TV to make a few recordings to see if there was any noise, and there was no noise on with it either. I might try switching around the receivers later tonight to see what happens.

Maybe the Red /White cables are going bad and they are fine till you move them slightly.

Is there any option to use a different type of connection to the tube type TV ?

 

[Nealio]

Alright just got home. The cables were going to the correct places, but I reversed them to see if it would make any difference. Negative... same thing.

I've also tried 3 different RCA/composite cables (2 of them were brand new). They all do the same thing. The TV only has the yellow/red/white RCA/composite connector on it. It does have a coax input, but it broke a while ago. I probably just need to get a new TV but it's served me well for so long that I'd like to keep it.

Anyhow, I wonder what could be interfering with that connection but not with the HDMI connection? Next up, I'll try switching the 2 receivers to see if it makes any difference.

 

[Jimbo]

Alright just got home. The cables were going to the correct places, but I reversed them to see if it would make any difference. Negative... same thing.

I've also tried 3 different RCA/composite cables (2 of them were brand new). They all do the same thing. The TV only has the yellow/red/white RCA/composite connector on it. It does have a coax input, but it broke a while ago. I probably just need to get a new TV but it's served me well for so long that I'd like to keep it.

Anyhow, I wonder what could be interfering with that connection but not with the HDMI connection? Next up, I'll try switching the 2 receivers to see if it makes any difference.

So your saying that it doesn't always do that on that input ?
I was wondering if the input was the problem, obviously the HDMI connection would be the way to go.

Any RF signals running astray could be causing it.
Are the Composite cables laying on other cables ?

 

[Nealio]

HDMI would be the way to go, but the TV I'd like to hook it up to doesn't have it.

There are some other cables that criss cross with each other... so I took all of the cables out and separated them so that the satellite ones are not touching any others. Same problem thought--that didn't seem to help. I also thought that possibly it could be an electrical problem in the room that could be causing just the analog outputs to be giving me problems for whatever reason. So I ran an extension cord to the same outlet that my other receiver works fine on, but I still got the same results.

Lastly, I tried swapping the 2 recivers I have. They both work fine in the other room (no or close to no noise), but they both produce a pretty loud hum / buzz when hooked up in the problematic room. I don't really know what to try next. Any more ideas?

 

[ebms1]

HDMI would be the way to go, but the TV I'd like to hook it up to doesn't have it.

There are some other cables that criss cross with each other... so I took all of the cables out and separated them so that the satellite ones are not touching any others. Same problem thought--that didn't seem to help. I also thought that possibly it could be an electrical problem in the room that could be causing just the analog outputs to be giving me problems for whatever reason. So I ran an extension cord to the same outlet that my other receiver works fine on, but I still got the same results.

Lastly, I tried swapping the 2 recivers I have. They both work fine in the other room (no or close to no noise), but they both produce a pretty loud hum / buzz when hooked up in the problematic room. I don't really know what to try next. Any more ideas?

the noise you hear is ac hum... you have an open gnd or a gnd loop....
you might try getting a circuit tester & check the outlet... if the tv is pluged into anothe outlet ,,try plugging everythong into one ... also are there any gnd disabiling divices in line like adaptors for ungrounded plugs...


i thought you said that one recvr did it & another didnt ... then you said that 2 recvrs did it in the same room ....??????

 

[Nealio]

Thanks for the reply embs1. I had a circuit tester on my tool shelf, so I tested all of the outlets in both rooms that the 2 receivers are in. They are all setup/wired correctly according to the tester. I do have the TV and receiver plugged into different outlets, so I'll try to plug them into the same power strip next. Do they make some kind of power strip/surge protectors that help with this AC hum, or is something like that not possible to fix so easily?

There are no adapters that convert 3-prong to 2-prong plugged in anywhere if that's what you are asking.

As for the which receiver does what... I guess I wasn't very clear. Anyways, both receivers have minimal noise when connected in room 1 (you have to turn the volume up almost all the way and be switching channels to really hear it). I'm fine with that because you don't notice it during normal viewing with normal volume. However, both receivers make the audio hum / buzz noise when they are hooked up in room 2 (the problematic room). Does that make sense?

 

[ebms1]

Thanks for the reply embs1. I had a circuit tester on my tool shelf, so I tested all of the outlets in both rooms that the 2 receivers are in. They are all setup/wired correctly according to the tester. I do have the TV and receiver plugged into different outlets, so I'll try to plug them into the same power strip next. Do they make some kind of power strip/surge protectors that help with this AC hum, or is something like that not possible to fix so easily?

There are no adapters that convert 3-prong to 2-prong plugged in anywhere if that's what you are asking.

As for the which receiver does what... I guess I wasn't very clear. Anyways, both receivers have minimal noise when connected in room 1 (you have to turn the volume up almost all the way and be switching channels to really hear it). I'm fine with that because you don't notice it during normal viewing with normal volume. However, both receivers make the audio hum / buzz noise when they are hooked up in room 2 (the problematic room). Does that make sense?

did you also check your power strip to see that it is grounded with the circuit tester...

does all your equip. have 3 wire plugs ???? has the tv a 3 wire or 2 & does any equip not have polarized plugs.... it seems that you have an open gnd somewhere......if you have a meter ... read from metal case to case ....see if you have a potenial....

 

[Nealio]

Yes, the power strip is good according to the circuit tester.

I see what you are saying now about the 3 wire / 2 wire plugs. I do have a DVD player and external speakers plugged in that have 2 wire plugs in the same outlet. I'll try unplugging everything that is 2 wire plugs and see whether or not that helps. The TV is 3 wire, but the receiver has a 2 wire plug though so I'll have to leave that plugged in.

What kind of a meter would I need to read the metal cases for a potential?

EDIT:

I tried unplugging everything in the entire room except the TV and the receiver. Didn't help at all.

I have been looking online and have come across AC hum filters. Do you think something like this would get rid of the problem? I know it's a bit pricey, but I'd really like to fix this problem.

http://www.zzounds.com/item--EBTHUMX

EDIT 2:

Amazon has several reviews that report that their ground loop audio hum / scrolling horizontal video lines were fixed with the AC hum filter I listed. I didn't notice until I turned the brightness really high on my TV that there are also scrolling horizontal video lines on my set when hooked up via RCA/composite yellow/red/white. Same thing happened when I moved the HDTV into the room and turned up the brightness--it did it with the composite cables as well as component, but not the HDMI cable. It sounds like it would be worth a shot to at least try it. If it doesn't work then I guess I could send it back or sell it on eBay. Here's what a few of the reviews on Amazon says:

"I had an annoying 60cycle hum appear after my satelite installer installed my new hi-def DVR. A quick search of the internet led me to the Hum X. Decided to order it but was a bit scepticle. Received in quickly and installed - viola!!! Hum gone!!! I am a happy camper!"

"I don't typically write reviews for products, but I am a technician and I had a ground loop in a television. I spent two whole days working on trying to eliminate the grounding issue and even had my electrician come over and try. Nothing worked. I decided to try this and it worked like a charm. I only wish I had this on the first day. I am going to start stocking these on my truck."

"When I added a new TV to my system I was getting a hum through the speakers. I plugged my power amp into the Hum X and the hum disappeared!"

 

[ebms1]

Yes, the power strip is good according to the circuit tester.

I see what you are saying now about the 3 wire / 2 wire plugs. I do have a DVD player and external speakers plugged in that have 2 wire plugs in the same outlet. I'll try unplugging everything that is 2 wire plugs and see whether or not that helps. The TV is 3 wire, but the receiver has a 2 wire plug though so I'll have to leave that plugged in.

What kind of a meter would I need to read the metal cases for a potential?

EDIT:

I tried unplugging everything in the entire room except the TV and the receiver. Didn't help at all.

I have been looking online and have come across AC hum filters. Do you think something like this would get rid of the problem? I know it's a bit pricey, but I'd really like to fix this problem.

Ebtech Hum X at zZounds

EDIT 2:

Amazon has several reviews that report that their ground loop audio hum / scrolling horizontal video lines were fixed with the AC hum filter I listed. I didn't notice until I turned the brightness really high on my TV that there are also scrolling horizontal video lines on my set when hooked up via RCA/composite yellow/red/white. Same thing happened when I moved the HDTV into the room and turned up the brightness--it did it with the composite cables as well as component, but not the HDMI cable. It sounds like it would be worth a shot to at least try it. If it doesn't work then I guess I could send it back or sell it on eBay. Here's what a few of the reviews on Amazon says:

"I had an annoying 60cycle hum appear after my satelite installer installed my new hi-def DVR. A quick search of the internet led me to the Hum X. Decided to order it but was a bit scepticle. Received in quickly and installed - viola!!! Hum gone!!! I am a happy camper!"

"I don't typically write reviews for products, but I am a technician and I had a ground loop in a television. I spent two whole days working on trying to eliminate the grounding issue and even had my electrician come over and try. Nothing worked. I decided to try this and it worked like a charm. I only wish I had this on the first day. I am going to start stocking these on my truck."

"When I added a new TV to my system I was getting a hum through the speakers. I plugged my power amp into the Hum X and the hum disappeared!"

another thought ... is youre dish grounded ... & where is it grounded???????????????...what is it grounded to ... is it on the same ground nas the house gnd??????/

 

[Nealio]

Yeah, last week the installer actually showed me where/how he grounded it. It is connected to the main house gnd, which runs off a pole that is attached to the electric meter. That is where the Dish Network installer put it as well back when I had Dish... and I had the same problem then as well (I had Dish up until about a week ago).

 

[bhelms]

Wow - Same as ebms1, I was guessing ground loop as well as I first started reading this thread, but it sounds like you checked everything I would have suggested. One thought, and this is a stretch - is it possible that the outlet you're using for the HT equipment is not bonded back to that same ground at the entrance where the dish is grounded? (It might be part of a subsystem that was grounded by other means, like a water pipe?) Your circuit tester will indicate if you have no ground at all (which is apparently not your problem) but it won't tell you how a circuit is grounded.

A possible test would be to remove all of the dish grounds temporarily (the messenger wire from the dish and the ground wire from the ground block) to see if the hum goes away.

 

[ebms1]

Yeah, last week the installer actually showed me where/how he grounded it. It is connected to the main house gnd, which runs off a pole that is attached to the electric meter. That is where the Dish Network installer put it as well back when I had Dish... and I had the same problem then as well (I had Dish up until about a week ago).

now ... what you need to do is see if your pole or box is grounded... check & see if you see a grn rod about straight down from your meter box ... a heavy wire should be going from the gnd rod to your meter box .... should be a heavy copper wire....about 3/16 in thick


other than this ... you might need an electrican

 

[Nealio]

The hum is gone! I'd like to give a BIG thanks to ebms1 for pointing out what the initial problem was (AC hum). I received the Ebtech Hum X from Amazon today and it's working as advertised! It took a few fidgeting tries, but all is good now--no AC audio hum or horizontal panning video lines! I initially had a few things plugged into a few different outlets, and my first attempt with the Hum X failed miserably. However, after plugging everything related to the TV/receiver/PC/speakers into 1 power strip (which was connected to the Hum X), all was well (and yes, I tried doing this without the Hum X connected, but I still got the hum). I ended up paying $63 for the Hum X, but as long as it continues to work I am totally fine with that price.

bhelms and ebms1: I'll try looking into those things in a few days and see about fixing the problem at the source. I'd just like a few days of it working correctly and me not having to mess with anything first.

Thanks again guys!