Help me with a noise problem please

Discussion in 'Amps, Pre-Pros & Receivers' started by Definitive_Tech, Feb 12, 2013.

  1. Definitive_Tech Audiophyte

    Definitive_Tech
    Joined:
    Apr 5, 2012
    Messages:
    4
    Likes Received:
    0
    Location:
    Albuquerque, NM
    Ok, I'm about at my wits end. I have a noise problem I can't figure out. Essentially the problem is a popping sound emitted from the front left and right and back surround speakers when the preamp is decoding and outputing the signal to the amps. The problem started when I purchased a N.O.S. Harman Kardon Citation 5.1 to run my surrounds. I already had an Emotiva XPA3 running the front left, right, and center. I never noticed the popping in the front left and right when the Emotiva was running them, but I purchased a N.O.S. Citation 7.1 which I bridged to the left and right. I was using the amp in my receiver to run the center until I more recently got a Emotiva XPA 100 to run the center.

    The popping sound is like using a 9 volt battery to test speaker polarity. It occurs also if the amps are already on before the receiver has finished it's start up. The receiver is an Onkyo TX NR809, which is just acting as a pre/pro. The rest of the setup includes a Directv digital box, Xbox 360, Oppo BDP 103, and a Panamax M5300PM as the surge suppressor/line conditioner. All the pieces are using HDMI from the Onkyo to the unit and then using the Onkyo analog outputs to feed the amps. I have done a ton of troubleshooting and have figured some things out. I figured it was the Onkyo at fault and sent it to their authorized repair center who told me they couldn't replicate my problem. After I sent the Onkyo to them I hooked up the Oppo to use it as a pre/pro while the Onkyo was gone and noticed it did the same thing!

    The Directv box would cause the pop anytime I changed the channel or muted, basically anytime the sound was processed. I fiddled around with it and turned off the Dolby Digital output and let it just output PCM. That stopped all popping except for muting and unmuting, and the shutdown or turn on where the Onkyo shut down before the amps. When the Onkyo is only getting the PCM signal it doesn't have to decode the signal because it is using the preset decoding option I chose. The Xbox will cause the pop under the same situations. Also ditto for the Oppo.

    I spent a good deal of time to route the power cables away as much as I could from the HDMI and RCA cables as well. The outlets being used check out ok and show good ground as the Panamax shows "wiring ok" as well. I have tried switching HDMI cables and RCA cables with no changes. I use the high end Monster and Blue Jeans/Belden HDMI cables as well as RCA. I even tried shielded RCAs I had lying around that I used for car audio, no change. I swapped the Citation amps to run the surrounds and no change. I hooked up the Emotiva on the fronts again, but noticed when my ears were right next to the towers that the pop was there with the Emotiva, but I was only able to hear it with my ears right by the speaker. That is probably why I didn't notice it before. I am so frustrated and at my wits end. I tried explaining to the tech where I sent the Onkyo to, but he had no idea what the problem is and just said he couldn't duplicate the problem. HELP ME PLEASE
  2. TLS Guy Audioholic Overlord

    TLS Guy
    Joined:
    Oct 30, 2007
    Messages:
    12,104
    Likes Received:
    4,876
    Location:
    Benedict MN
    I have been pondering your problem all day.

    These types of problems are usually due to processors, or power supply problems. Since this seems to affect multiple units and different ones to a different extent, I suspect that Panamax unit is the problem

    If you have not already, then cut it out of the equation. I have had friends have these type of units, and seen them cause all manner of problems. In my view those type of units are pretty much a scam. My view is they can and frequently do cause more problems than they solve.

    My view on power protection, and it is important, is whole house surge protection and properly rated commercial UPS devices. I use APC devices. Basically if the unit does not have a big battery, than can take over when the power is out of spec or goes down, then the unit is a waste of space.

    If you have cut the Pananmax out, and that means unplugging it and plugging things into something else, than I would get those bridged amps out of the equation. I am not in favor of bridging. That is another trick that often leads to a host of problems.

    After that there is not much I can do to help without being there with instruments.
    • Like Like x 1
  3. M Code Full Audioholic

    M Code
    Joined:
    Oct 26, 2009
    Messages:
    468
    Likes Received:
    149
    Location:
    Joshua Tree, CA
    You have a grounding problem between the components..
    You have isolated certain things such as the noise pulse is generated when the Onkyo audio processor chip is switching modes. Suggest you try a couple of things..
    1. Try connecting the AC power of the Onkyo into a different electrical outlet away from the other components
    2. Try connecting a separate chassis ground wire between the components, make sure you touching bare metal on each chassis
    3. Cable boxes and Direct tuners frequently present a unique grounding dilemmas, especially through its coax feed You might try a ground isolator on the coax
    4. Also an RCA ground isolator between the lineouts of the Onkyo and the HK amp may help

    There no EZ fix-all for these type of problems, each component needs to be isolated and grounded. Over the years we have worked with the FCC for minimizing and/or eliminating certain local RFI issues, takes trial & error...

    Just my $0.02... ;)
    • Like Like x 1
  4. PENG Audioholic Warlord

    PENG
    Joined:
    Oct 23, 2004
    Messages:
    7,893
    Likes Received:
    2,199
    Location:
    Ontario
    I suggest to remove all HDMI connections and see if the pop remains. I remember someone was having a similar though not exactly the same issue, and it was HDMI related.
    PENG,
    • Like Like x 1
  5. Cos Audioholic Chief

    Cos
    Joined:
    Dec 26, 2005
    Messages:
    935
    Likes Received:
    249
    Integra DHC-80.3 and Anthem MCA 50/20 Amps (I did not have popping, just loud Hum)

    "The popping sound is like using a 9 volt battery to test speaker polarity. It occurs also if the amps are already on before the receiver has finished it's start up. The receiver is an Onkyo TX NR809"

    I spent 2 weeks and numerous suggestions from PENG and other excellent resources on this site and was unable to resolve the issue

    My situation:

    - My amp would turn on from 12v trigger and even tested manual and would hum loudly on all speakers while my Integra went through HDMI setup, once it finished they were whisper quiet playing multi-channel audio
    1. When it tried to play Dobly Digital or DTS content that was 5.1 channel my back rear speakers would hum (i.e. the back surrounds which were not supposed to be getting any signal, which was hard to isolate due to 4x dipole speakers)
    2. This occurred on both my Xbox 360 and Cablebox content when Dobly D 5.1 was being played. I was finally able to figure out part of the problem when I completely disconnected the back surrounds
    3. I reconnected the rear surrounds and selected 5.1 in Speaker Setup, but even in that mode the 2 Back Speakers plugged into the amp, they would hum, so the only way to eliminate the noise during normal playback was to remove those speakers and go 5.1 (This did not eliminate the hum on HDMI Startup or Firmware upgrade menu)
    4. I hooked up my amps to my old AVM 30 Anthem and it worked perfectly silent, but I was also not using HDMI.
    6. All speakers would hum anytime I would try to do a firmware upgrade or when I tried to do level calibration, but would return to quiet when I was back on source
    7. I had a dedicated Isolated 20amp circuit installed for my HT gear and that did not fix the issue.
    8. I finally spoke to Bob at Integra (He is the troubleshooter for professional installers) who basically told me that there was pretty much nothing more he could think of to test it out and suggested for some reason there was a compatibility issue with my Amp and the Integra
    9. My dealer lent me his Integra and had the same issue
    9. My dealer then lent me a new Halo A52 amp and I did not experience any of the same issues as it was quiet on all modes

    I have read a very few posts on bad HDMI boards with Integra/Onkyo, but I am not sure if that really is the issue.


    At that point and two weeks of testing I finally said "screw it" and bought the A52 and J23 Halo amps for 2k.
    - 2k for both amps was a incredible deal and even though they had less power than the Anthems, I was thoroughly impressed by the quality of sound. I was trouble shooting issue and using 007 Skyfall Bluray as sample and noticed a significant difference in sound quality between the two.
    - My dealer is evil, he must have known that I would want those amps when he let me borrow them LOL :)
    Last edited: Feb 15, 2013
    Cos,
    • Like Like x 1
  6. Definitive_Tech Audiophyte

    Definitive_Tech
    Joined:
    Apr 5, 2012
    Messages:
    4
    Likes Received:
    0
    Location:
    Albuquerque, NM
    Hmm, my personal thoughts lean toward ground and the HDMI. I used a different conditioner that wasn't as good, a Monster, and had the same issues. I hooked up the Oppo and the 7.1 in my bedroom only to have the same problem still. I know the 7.1 is fully ground isolated for each channel, so there is no shared ground internally. That only means, I think, that somehow the signal path is getting a voltage spike that is being amplified by the amp. I know the Panamax has separate, isolated filter banks, so that makes for more isolation there... By the way, I also tried disconnecting the ground run for the Directv, but that made no difference too.

    I'm curious what differences between the Emotiva and the H/K would cause the much more audible popping with the H/K? They are both class A/B designs too. One thing I need to do is disconnect the HDMI from the Oppo and see if running the audio outs directly to the amp changes anything. Ugh... I guess nothing comes easy. Thanks for the input so far
  7. Hobbit Full Audioholic

    Hobbit
    Joined:
    Nov 26, 2012
    Messages:
    280
    Likes Received:
    59
    Grounds are fickle to say the least, even a few ohms can make a big difference. When I worked in a fab we had to drill deep holes into the ground and put big copper rods into them. Then a drip system was installed to keep the ground moist around the rods. These rods were then tied to a big grid that ran under that fab floor. All this because we live in the desert and earth ground floats ~8-12 ohms. A difference in true grounds between equipment in the real world, even just a couple of ohms, can make weird things happen.

    Today I went to a friends house to help him solve a ground problem. I grabbed a wire and started touching it between the different components. After touching this to about every combinations I landed on the right combo, the 2 way coaxial digital splitter, going to his cable box and modem, and his amplifier. When I touched these two together the speaker hum vanished. Went ahead and put connectors on each end of the wire and tied the amp and digital splitter. The key point in this exercise was making absolutely sure you are making a good connection. It took a couple of rounds of touching and retouching to nail it. You would think connecting between the cable box and amp (I even touched the outside of the cable where it goes into the box) would have done the same thing? However, I'm not going to take them apart to find out why it didn't. (note: I also went outside and it appeared the cable line had a good earth ground)

    I personally don't buy it has anything to do with the HDMI. I know Onkyo/Integra had issues with these boards a couple of years ago.....
    • Like Like x 1
  8. PENG Audioholic Warlord

    PENG
    Joined:
    Oct 23, 2004
    Messages:
    7,893
    Likes Received:
    2,199
    Location:
    Ontario
    I would tend to agree with you, but others (not Cos) had experienced similar issues. In fact Cos issue is hum, not pop, so I think his issues are most likely related to grounding but it could still be HDMI circuit grounding related because I think at one point he mentioned he did not have the hum when he was using another prepro and that one does not have HDMI. As the OP said, it could be something wrong somewhere that may be causing signal spikes that get amplified. I am not familiar with HDMI and related circuit design so I wouldn't rule that out. I also thought there might be relay switching and some capacitive coupling involved in that part of the circuit, and if something there went wrong, it might just be a source of spikes that could be amplified to make those short pops. I thought the OP could easily remove all his HDMI connections so there would be no intentional signals other than when he switch the inputs, to start eliminating HDMI circuit being part of the problem.

    As for this grounding thing, that is quite possible, but in most cases I think we both know grounding issues generally result in humming kind of noise, not shot pops that are typically created by short pulse/spike but then anything is possible.
    PENG,
    • Like Like x 1
  9. jeffro Audiophyte

    jeffro
    Joined:
    Aug 22, 2012
    Messages:
    2
    Likes Received:
    0
    Just figured i would post the fix since i have been dealing with it for over a year and finally resolved
    this issue with my two citation 7.1's
    The problem is with DC Offset coming off the amps outputs creating a pop/popping sound whenever the audio changes or enguages
    i had this fixed at my theater install/repair shop. The fix is they installed caps inside the amps at all of the outputs & presto no more
    annoying popping.this is also a known problem with some Adcom amps as well.
    Hope this helps anyone else with this PITA problem

    Jeff.
    Last edited: Mar 31, 2013
  10. TLS Guy Audioholic Overlord

    TLS Guy
    Joined:
    Oct 30, 2007
    Messages:
    12,104
    Likes Received:
    4,876
    Location:
    Benedict MN
    That is a really crude fix and will limit bass response.

    I would not keep amps that created DC offset like that in my system. They would go down the road pronto.
  11. jeffro Audiophyte

    jeffro
    Joined:
    Aug 22, 2012
    Messages:
    2
    Likes Received:
    0
    Thanks for the input TLS GUY.

    im not RICH & cant afford to send them down the road pronto !!!!!

    i was also made aware off the bass response possibility but the dc offset was so minimal
    i decided to go for it & my system sounds just fine to me.
    but thanks for taking a shot at raining on my parade.

Share This Page

  • rbhsound.com
  • BlueJeansCable.com
  • Emotiva.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
  • CEDIA