Ground loop hum eliminated.............. the expensive way!

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BlueSky

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I have had this nagging, low level, 60Hz hum in my system that was identified as occurring any time a piece of equipment interfaced via an HDMI cable was connected. The hum wasn't loud but it was there and, in between music titles or very low level passages, it was apparent. No amount of tinkering with the equipment's power supply cables, external grounding configurations or any other measures I could think of were effective.

What I ended up doing was replacing a bunch of copper HDMI cables with fiber optic HDMI cables. No more annoying hum!

The things we do to
 
Congratulations !

Hum like that can be annoying. So happy you found a way to eliminate it.
 
Thanks Joe! I found some considerably less expensive and shorter cables on line that filled the bill.

Joe
 
Hmmm (re hummm), I've had that exact problem with HDMI "contaminating" my 2 channel system (when connected to my Oppo player). What brand fiberoptic HDMI cable have y'all used? Does it require some kind of optical to electric converter to work with older HDTV's?
 
The cables include the converters embedded in the connectors and are self powered by the ports themselves or, in the case of FIBBR's Crystal Series, as a result of rectifying the AC currents carried in the cables. Older HDMI TV sets should be no problem as the cable are compatible with earlier HDMI specs. Amazon has them as well as Monoprice. Not cheap but does the trick.
 
Nice. Video gear often isn't designed to avoid ground loops in the audio gear to which its are connected. Optical avoids all that :)
 
I ordered this FURUI brand fiber HDMI cable from Amazon, which also offered shorter lengths, and less expensive than the FIBBR series... https://www.amazon.com/dp/B07CGKDQDD.

It arrived today, but, unfortunately, did NOT eliminate the ground loop hum in my setup. Fortunately, FURUI allowed me to return it for full refund.

I wonder if the FIBBR design is different, and still might work?
 
sleepysurf said:
I ordered this FURUI brand fiber HDMI cable from Amazon, which also offered shorter lengths, and less expensive than the FIBBR series... https://www.amazon.com/dp/B07CGKDQDD.

It arrived today, but, unfortunately, did NOT eliminate the ground loop hum in my setup. Fortunately, FURUI allowed me to return it for full refund.

I wonder if the FIBBR design is different, and still might work?
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I know you've probably already done this but first confirm that it is indeed the HDMI cable causing it by disconnecting, listening and then reconnecting for confirmation. The FIBRR cables, unlike the less expensive ones that I bought from D-Tech, do not use the four copper conductors to carry power from one connector to the other. If I understand FIBRR correctly, they use a different technique to obtain power for the copper to optical transceivers and back again. FIBRR does, however, use a single copper conductor but, apparently in my situation at least, does not conduct the ground currents that lead to hum.
 
Yes, I've confirmed it's the HDMI cable running from my Oppo UDP 205 (likewise with older BDP 95) to my Denon receiver into Sony HDTV. Everything is plugged into the same circuit. I've struggled with this for years... even trying an Ebtech Hum X on the Oppo, C-J Preamp, and Denon respectfully, without success. I've dealt with it by connecting the HDMI cable only when watching a DVD.

I'll contact FIBBR to see if they likewise offer refund if it doesn't work.
 
Are you sure it’s a ground loop and not just noise in your system? Does it adjust with volume?

Unplug everything, and I mean everything then start with the amp to the speaker and see what happens. Then start plugging in everything until you hear the hum.

Ensure all power cables are not running parallel alongside interconnects and speaker cable.






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sleepysurf said:
What brand fiberoptic HDMI cable have y'all used? Does it require some kind of optical to electric converter to work with older HDTV's?
Click to expand...

In my geographic area, FIBBR and Moshou are more popular with videophiles. I use a cheaper brand SGO.

You use it just like any other HDMI cable regardless of what kind of HDMI device you have.

However, they draw power from the HDMI devices they connect to for the optical conversion electronics, so there may be incompatibility with specific devices. It's best to make sure you can return the cable if it does not work for you.

Very often antenna feed also causes ground loop issues. Some people got rid of it by a ground isolator for the antenna.
 
sleepysurf said:
I'll contact FIBBR to see if they likewise offer refund if it doesn't work.
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If you purchase the FIBBR cables through Amazon, as I did, returns are pretty much a guarantee.

(P.S. For me, I chose cable from their "Crystal" lineup)
 
Jack said:
Does lifting the ground on the Oppo do anything?
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No. Lifting the ground does not help. Antenna coax to cable box is, likewise, not the source. The hum is not related to preamp volume, so not tube noise. It's clearly due to the HDMI connection to my old Denon receiver, HDTV, and Frontier cable box. Interestingly, unplugging all three of those simultaneously eliminates the hum, but unplugging each of them individually does not, so I can't isolate it to any specific component. Those are all powered by a Monster HTS 3500 conditioner (plugged into same 20A outlet as the rest of my system), so it's possible that device is the source of the problem. I'll try the FIBBR cable next, before pulling the Monster conditioner out of the system.

Of note, I emailed FIBBR asking if they'd confirm their design can eliminate a ground loop, but never heard back. Guess I'll just buy it from Amazon, and return it if it doesn't work.
 
I opened the cable housing box (you may have this inside or outside) where the cable comes in from noticed there is a grounding wire along side the incoming cable and noticed it was not tight, I mean it was like a little better then finger tight. After I tightened this down things improved.




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If the Frontier cable box is integrated into a joint two channel/HT setup then having any of the three HDMI cables connected will cause the noise. So disconnecting the cable box from the incoming line alone doesn't stop the hum? Have you tried to take the Frontier box in and swap it for a new one? I doubt it is the HTS-3500 if the common denominator for stopping the hum is removing the HDMI cables. And like Ultrafast said check the cable companies ground wire at the junction box.
 
sleepysurf said:
Of note, I emailed FIBBR asking if they'd confirm their design can eliminate a ground loop, but never heard back. Guess I'll just buy it from Amazon, and return it if it doesn't work.
Click to expand...

I had the same response from FIBBR which was NADA! Zippo! Bupkiss! Interestingly, I had problems with FIBBRs cables. Two of my sources worked fine. Two did not "like" the cables. The two that didn't work were a relatively new ROKU 4K streamer and a relatively old Toshiba HD-DVD player. Those two devices worked well will a Monoprice Ultra Slim fiber optic cable but 100ft was a little long for my three foot need. Amazon was very gracious and took back the cables I did not need and am trying another solution, Celerity Tech, which is pure fiber, no copper running concurrently, and power if, needed, is supplied via an attached USB connection at either end of the cable. CelerityTech is California-based and the COO was quick with a response on every question I had about her cables, which I appreciated, because customer service goes a very long way with me. These cables are also available on Amazon although they are a new vendor.

YMMV on whether or not FIBBR's cables will work with your sources but thought I'd share my experience.
 
BlueSky said:
I had problems with FIBBRs cables. Two of my sources worked fine. Two did not "like" the cables.
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As I said in post #14.

Also note that there are different grades of fiber HDMI cable. Only 18Gbps version should be used - but with some brands it costs much more than 10.2Gbps versions (not good).
 
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