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HDMI to CAT5e to Stop Ground Loop?

post #1 of 8
10/7/11 at 10:45am
Thread Starter 
I recently added a Wyred 4 Sound DAC-2 with home theater bypass to improve 2 channel music in my home theater. Now I've got a ground loop hum I just can't resolve.

Actually, I can fix it, but I'm not comfortable with how I fix it. A 3 prong to 2 prong cheater plug on the DAC works, but I'm not leaving that in my system. Even a little risk of electrocution is too much risk for my liking. An Ebtech Hum X also fixes it, but it's a devices with no UL or CSA approvals. Again, that makes me a little nervous.

Unplugging the HDMI cables from my satellite receiver, PS3 and out to my projector makes the hum go away. HDMI from my Xbox and blu-ray player can remain plugged in without any hum.

So I've read that HDMI to CAT5e can stop a ground loop. Does anyone know if this is true?

If so, does anyone have any experience with the cheapie Monoprice extenders (either the non-powered one or the wall plate type)? Do they impact video and audio quality? The Cat5e run would be very short. Probably about 3 feet. I know this isn't the normal use for these extenders, but at this point I'm ready to try anything.

I'd just order one from Monoprice to test, but I'm in Canada, so I want to know it works before spending money to ship it here.

Thanks,
Tyler
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post #2 of 8
10/7/11 at 10:54am
Quote:
Originally Posted by tjayl View Post

I recently added a Wyred 4 Sound DAC-2 with home theater bypass to improve 2 channel music in my home theater. Now I've got a ground loop hum I just can't resolve.

Actually, I can fix it, but I'm not comfortable with how I fix it. A 3 prong to 2 prong cheater plug on the DAC works, but I'm not leaving that in my system. Even a little risk of electrocution is too much risk for my liking. An Ebtech Hum X also fixes it, but it's a devices with no UL or CSA approvals. Again, that makes me a little nervous.

Unplugging the HDMI cables from my satellite receiver, PS3 and out to my projector makes the hum go away. HDMI from my Xbox and blu-ray player can remain plugged in without any hum.

So I've read that HDMI to CAT5e can stop a ground loop. Does anyone know if this is true?

If so, does anyone have any experience with the cheapie Monoprice extenders (either the non-powered one or the wall plate type)? Do they impact video and audio quality? The Cat5e run would be very short. Probably about 3 feet. I know this isn't the normal use for these extenders, but at this point I'm ready to try anything.

I'd just order one from Monoprice to test, but I'm in Canada, so I want to know it works before spending money to ship it here.

Thanks,
Tyler

I would think the Cat5e cable would have the same ground but I'll leave it to the experts to say. Obviously the one that would guarantee non-dueling grounds would be a fibre-optic solution. I've seen those used many times to solve this situation.

That said, have you tried different wall power plugs in the room? If you can find one on a different circuit that might work.

And remember, HDMI is a digital connection. You either get the signal or you don't. So as long as you are getting the HDMI signal, you won't have any difference in audio or video. The exception to that was some of the early wireless extenders that downrezzed the signal to make it fit within the available bandwidth. Some single-wire cat 5 extenders attempted that as well.
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post #3 of 8
10/7/11 at 12:25pm
Quote:
Originally Posted by tjayl View Post

I recently added a Wyred 4 Sound DAC-2 with home theater bypass to improve 2 channel music in my home theater. Now I've got a ground loop hum I just can't resolve.

Best to fix the problem at the source.
Quote:


So I've read that HDMI to CAT5e can stop a ground loop. Does anyone know if this is true?

There is nothing inherent in what a Cat 5/5e/6 media adapter has to do that will eliminate a ground loop. I suppose it is possible some might, depending on design. A fiber media adapter certainly will. Not cheap though.

Let us know how it goes.
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post #4 of 8
10/7/11 at 1:12pm
Thread Starter 
Quote:
Originally Posted by Colm View Post

Best to fix the problem at the source.

Ya, I've exhausted all the troubleshooting tips I've found. Everything is on the same circuit, run off the same power bar. No cable TV. Still hums with the satellite cable (and receiver for that matter) unplugged. It was wishful thinking on my part that maybe Cat 5 would be a simple fix.


Quote:
Originally Posted by Colm View Post

There is nothing inherent in what a Cat 5/5e/6 media adapter has to do that will eliminate a ground loop. I suppose it is possible some might, depending on design. A fiber media adapter certainly will. Not cheap though.

Let us know how it goes.

I figured, since it was still grounded. Ah well. Might have to sell the DAC. I bought it used so I shouldn't take much of a hit if I do.
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post #5 of 8
10/7/11 at 2:19pm
I'm curious, while you hear the hum, does touching any component including the projector make the hum go away? How far apart is the projector from the rest of the equipment? If you used component video to the projector instead of HDMI do you still get the hum with the HDMI cable disconnected and component video connected?
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post #6 of 8
10/7/11 at 6:14pm
Something is funny about the first post though. You say that you recently add one piece of equipment resulting in hum... BUT then you say you have to remove cables (hdmi) from a bunch of EXISTING equipment makes it go away???? So you are telling us that IF you remove the new piece of equipment and leave your other connections as they were, you have hum in your system???? Not knowing exact how the wyred box works but I do see from the site that it indicates a "non-standard hdmi format" not sure what that means but if you would clear up some of the ???? about your setup (like how are all the boxes connected and to what) perhaps there are other solutions / alternatives.
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post #7 of 8
10/8/11 at 1:48pm
Thread Starter 
Quote:
Originally Posted by alk3997 View Post

I'm curious, while you hear the hum, does touching any component including the projector make the hum go away? How far apart is the projector from the rest of the equipment? If you used component video to the projector instead of HDMI do you still get the hum with the HDMI cable disconnected and component video connected?

I haven't tried touching the projector. I'm away for a few days but will try that next week. The projector is across the room from all the other gear (15 ft) No chance to use a component cable without dismantling everything to move it closer. The power for everything is run off the same circuit.

Quote:
Originally Posted by budwich View Post

Something is funny about the first post though. You say that you recently add one piece of equipment resulting in hum... BUT then you say you have to remove cables (hdmi) from a bunch of EXISTING equipment makes it go away???? So you are telling us that IF you remove the new piece of equipment and leave your other connections as they were, you have hum in your system???? Not knowing exact how the wyred box works but I do see from the site that it indicates a "non-standard hdmi format" not sure what that means but if you would clear up some of the ???? about your setup (like how are all the boxes connected and to what) perhaps there are other solutions / alternatives.

There was no humming until the new gear was added.
Connections are as they were with the exception of the front l and r interconnects now run from the receiver's pre outs to the HT bypass inputs of the dac and then the outputs of the dac go to the amp. It used to all go from the receiver to the amp. I'm not using the HDMI on the dac. Just an digital coax from my squeezebox for music.

All other sources (blu-ray, satellite, gaming systems) use hdmi into the receiver and are handled completely by the receiver and amp. As mentioned, the front l and r run through the dac when any of those but the HT bypass is used.
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post #8 of 8
10/8/11 at 2:27pm
OK... thanks. Ground problems are no fun. Of course, you have tried elimination on the some of the cable route. For instance, have you removed the "pre-out cables" BUT left the "amp ins" connected, and vice versa.... to see if you have a "broken/bad" connection/cable/connector on any of those areas?
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