Integra DHC-80.3 Hum Issue on Dolby Digital Content

[Cos]

I purchased an Integra 80.3 DHC-80.3 and am having a difficult time with hum issue, but what is strange is when it happens. When I turn it on, it hums loudly when it goes through HDMI setup, after which is extreenly quiet. If I play multichannel music via my Marantz UD5005 it is fine. I can watch TV and it is fine as long as the content is not Dobly D (I assume this is Dolby Digital) Anytime there is a Dolby D on the display all 6 of my speakers hum very loudly, and I do mean you can hear it almost downstairs. I did the normal checks, (cables, cheater plugs, ground loops) etc. I disconnected the cable completely from my setup, but even when I was playing with my Xbox 360, since its 5.1 I experienced the same type of hum. On a side note if I watch cable TV on channel that is not Dolby D, there is no HUM. Do I have a bad unit or am I missing something. I did upgrade to the latest firmware immediately when I got the unit and it was completed. Thanks!

 

[Cos]

One thing to add, is when I hooked it back up to my old anthem unit, it worked fine. I had such a tough time with Marantz a while back, so I hope I am not going to have to go through this again. What is strange is when it happens.

 

[AcuDefTechGuy]

If it were me, I would have to guess there is something wrong with it.

Have you tried to play something with DTS?

Makes no sense to me why DD would cause any hum noise.

One bad thing about some separates - hum noise.

I bet a plain AVR with no ext amp would not even have a problem.

 

[Rickster71]

Something makes me want to rule out the possibility of a ground loop first.

It could very well be your Integra. It's just easier to check for a common ground loop first.


You'll need to try this process of elimination, one by one:
First - disconnect your coax cable wire. Listen to see if that did anything.
Second - plug everything into one power strip. This gets you on the same circuit and the same ground.
If it's a ground loop you'll be able to isolate the offending unit by unplugging them (one by one) or adding them to a common power strip

 

[AcuDefTechGuy]

I would just get a cheater plug. If the hum is gone, it's probably ground loop?

 

[Cos]

I used a cheater plug as part of my original testing, because of what I have learned from these forums Unfortunately it did not work. My first though was also a ground loop through the cable, I completely disconnected it. When I played the Xbox 360, when Digital came up on the display hum appeared, so not a cable ground loop issue. I have all my components plugged into Monsterpower 350 or can't remember the series number, except my amp, because anthem says not to in their manual, but I did so anyway and still had the same issue. I had a cheaper tripplite powerstrip and moved everything to that, still had the issue. Ran a long extension cord to use a different circuit, still the same issue. At this point I think its the Pre. My dealer gave me his demo unit to test out, so I am going to repeat the process again step by step just to make sure. Thanks as usual for all of the suggestions. The delay in my response was the fact I was at UFC on Fox 6 last night and it went from 2-9:30pm. Going to troubleshoot now

 

[Grador]

It's sounding like the DD decoder has probably bit the dust.

 

[Cos]

I thought that as well, but I borrowed my dealers 80.3 and have the same issue. At this point I am having an electrician do an inspection and install a dedicated circuit for my Home Theater area. I am curious is their is a ground loop fault or something else going on. Its funny that my old AVM30 Anthem works like a champ when I was testing

 

[Hobbit]

I had a similar issue with my 40.2. I ran a ground wire between the chasis of Integra and my main amplifier (Acurus) and the problem went away. An easy test is to grab a piece of speaker wire and touch it to both chasis. If this is the issue you'll notice right away. Also, I've seen issues when systems were plugged into two outlets and one was either on a different circuit and/or mis-wired.

My previous system had a slight hum with my ears to the speaker. When I got the Integra the hum was audible while siting on the couch. I think some of the issue is the Integra does not have a 3 prong plug (this bothered me....). Perhaps I should have grounded the amp and the pre/pro on my previous system! But now it's quiter than ever.

PS: I almost forgot, but at my last house I had an issue with the cable line coming in. I called the cable company and the came and installed a ground break for free.

 

[Cos]

Thanks for the input, I have eliminated the cable ground issue as it has no impact on my line. I am going to try grounding the amp/preamp. My amp (anthem) has a ground screw, but where did you ground it on your 40.2?

 

[Rickster71]

Thanks for the input, I have eliminated the cable ground issue as it has no impact on my line. I am going to try grounding the amp/preamp. My amp (anthem) has a ground screw, but where did you ground it on your 40.2?

A screw that goes into the frame/chassis, preferably one that isn't painted underneath.
Now that I know the Integra doesn't have a ground pin, it's sounding like the neutral connections need to be tightened. Ground & neutral are bonded back at the main panel.
Your idea of having an electrician look at things (if bonding the two units doesn't work) was a sound one.

 

[TLS Guy]

A screw that goes into the frame/chassis, preferably one that isn't painted underneath.
Now that I know the Integra doesn't have a ground pin, it's sounding like the neutral connections need to be tightened. Ground & neutral are bonded back at the main panel.
Your idea of having an electrician look at things (if bonding the two units doesn't work) was a sound one.

This is a really strange one Rick. I can not fathom why this only shows up on Dolby Digital! The fact that an identical unit also does it in his home and not elsewhere clinches the source of the problem to be his home.

I hope the OP stays in touch. I want to know the outcome of this. As I say, this is a highly unusual situation.

 

[Hobbit]

Thanks for the input, I have eliminated the cable ground issue as it has no impact on my line. I am going to try grounding the amp/preamp. My amp (anthem) has a ground screw, but where did you ground it on your 40.2?

On my 40.2 there is a screw for earth ground. However, you should be able to use any of the chasis screws.

 

[Hobbit]

This is a really strange one Rick. I can not fathom why this only shows up on Dolby Digital! The fact that an identical unit also does it in his home and not elsewhere clinches the source of the problem to be his home.

I hope the OP stays in touch. I want to know the outcome of this. As I say, this is a highly unusual situation.

Ground issues can have very weird results. Besides having a hum, I had an intermittent phantom talk show coming through only my right rear surround speaker! This actually threw me for a loop. I started chasing down the Directv box and the cable to it. When the cable was unplugged the talk show disappeared. Getting the amp and pre/pro chassis tied together fixed all the problems.

 

[Cos]

I definitely plan on staying in touch I don't know what the issue is with my equipment. I am getting a dedicated isolated 20amp circuit added to my electrical panel as well as having it checked for any issues. I ordered a pair of blue Jeans interconnects, just because they were not super expensive and want to make sure its not any of the cables. At this point at least I will not it will not be a ground issue caused from my house and I needed to get a dedicated circuit for my equipment anyway. Very frustrated at this point.

 

[PENG]

So let's recap, you had that problem with the AV7005, now with the Integra, yet no problem with Anthem prepro? I have used quite a few pre+amp, prepro+amp, AVR+amp combinations in the past several years using Denon, Yamaha and now Marantz products without any hum or noise issues. I really don't think it is a particular brand related issue. You mentioned before other AV7005 owners experienced similar issues but that seemed quite normal considering the fact that the AV7005 is likely one of the best sellers in recent prepro history. I google searched hard after what you said and found a few, just a few that reported such issue, that is not out of the ordinary.

From what you are telling us now, it would seem to be a different issue than ground loop because it only hums when trying to do DD, but then what is the odd that your loaner is doing the same? This is beginning to sound like a mystery. If and when you finally find the root cause please do share the information. I am sure I am not the only one who really would like to know what the heck the problem is. As far as connecting the Anthem and Integra chassis together, I doubt it would make any difference if the problem only shows up in DD, but you can try. As you said the Anthem has a screw for such connection but it may be hard to do with the Integra as you sure don't want to scratch off the paint job.

Have you tried the suggested way to connect one thing at a time to try and narrow down which piece of equipment would bring about that hum? Again, as ADTG suggested, and you have already tried that, i.e. the cheater plug, so ground loop really is not likely to be the reason.

 

[Cos]

I completely tore apart my HT and built it back from the ground up. I did it channel by channel and device by device and still the same problem occurred. I had it hooked up with only the blu ray player and on DTS and Dolby content it hummed loud. I tried it just with my xbox and it hummed loud again. On multichannel it is fine, on two channel it is fine. When the 80.3 boots up HDMI setup it hums until it finishes the setup process. When I went to do a firmware upgrade it will hum. The 80.3 Does have a ground screw located next to the phono input, so I am going to use that to connect to my amp tomorrow when I try to set it up. No one wants to figure out the problem more than I do . If it didn't work with my AVM 30 I would think its the Amp, who knows it still may be. My dealer is checking out the issue with the 80.3 he has of mine to see if he has the same problem. I may borrow one of his amps to see if the issue is amp releated, I really don't know at this point and to be honest I am tired repeating this process. If it turns out to be the amp, do you have an suggestions for a solid 7 channel amp to pair with it in the 2k price range? Thanks! My speaker setup is listed below, but I upgraded to the Studio 100v5s and CC690v5 everything else is the same

 

[PENG]

Does the Anthem has HDMI ? Was the Marantz hum problem same in nature as the Integra?

 

[Rickster71]

I thought that as well, but I borrowed my dealers 80.3 and have the same issue......

Was wondering if the dealer's 80.3 has this issue back at his shop?
It would help narrow this down a bit.

 

[Cos]

-Dealer is checking the unit at his shop he is supposed to let me know.
-Good point the AVM 30 does not have HDMI, I had to use component cables & TOS for hookup

Marantz hum was not as dramatic as the Integra. If I was 8ft away I could not hear it. I could hear the hum about 5' away from speakers if I really tried to listen and could not hear it from surrounds. Integra was loud on all speakers, loud enough I could hear it downstairs. I have 3 different types of Manufacuter's HDMI cables, Basic Cables to Go on Cable Box, Higher end on Blu-ray, xbox. They are both shielded and not more than a 1M cable. I doubt the cable is the issue as I have tried 1 HDMI device at a time.