Still trying to get rid of the buzz with my AV7005

[darien87]

Hey guys,

I've gotten the electrical buzz in my system down to a manageable level. Now you have to put your ear up to the speaker to hear the noise. At first it was putting a cheater plug on my Behringer amp that decreased the volume of the buzz. But the really annoying thing is that now the buzz is just constant and doesn't seem to be affected by anything I try.

I had an electrician over at the house this morning and he said that the grounds are all fine. He checked the main breaker box and replaced one of the breakers that he said was a little loose but he didn't find anything wrong with the electrical. He also told me that the screw that I had used to ground the cheater plug to the socket wasn't doing anything. I guess the screw didn't actually attach to anything metal in the outlet or something. This makes sense because when I previously tried attaching a ground wire from the back of the Marantz to the outlet, it didn't help.

One thing the electrician suggested I try was some sort of donut shaped magnet that he said you put your speaker wires through. He said that this would get rid of the buzz but he couldn't think of what it was called. He said it runs about $20. Would any of you know what this thing is?

 

[j_garcia]

Comes on most monitor cable for the same reason. Didn't figure it would work on a power cord, but sounds totally worth trying.

Amazon.com: ferrite core for power cord

 

[Ponzio]

Aren't ferrite cores more for RF interference? I was in the telecommunications industry for 35 years and don't remember ever using ferrite cores for power cords.

I would take it in to a Marantz service shop first to make sure the case is properly grounded. Just my 2 cents.

 

[darien87]

Comes on most monitor cable for the same reason. Didn't figure it would work on a power cord, but sounds totally worth trying.

Amazon.com: ferrite core for power cord

The electrician said to put it on the speaker wires, not the power cord. I'll drop by Fry's today and see what they have.

 

[j_garcia]

Aren't ferrite cores more for RF interference? I was in the telecommunications industry for 35 years and don't remember ever using ferrite cores for power cords.

I would take it in to a Marantz service shop first to make sure the case is properly grounded. Just my 2 cents.

He's already on his second unit

The electrician said to put it on the speaker wires, not the power cord. I'll drop by Fry's today and see what they have.

Ah, thought he was saying power cord, but that's what they are and Frys might have them. If they don't Halted in Santa Clara should: HSC Electronic Supply - Silicon Valley's Electronic Marketplace

 

[darien87]

Fry's didn't have anything. I'll give Halted a shot.

 

[jcl]

You can try Radio Shaft as well - RadioShack® Snap-Together Ferrite Choke Core - RadioShack.com or Snap Choke Core - RadioShack.com

 

[Ponzio]

This has been bugging me now as much as it bothers darien87.

I really don't believe a ferrite core(s) will get rid of electrical hum, from my own personal experience. darien87 I don't know how far you've gotten in resolving the issue but you might want to start troubleshooting from the beginning. Disconnect all associated equipment (CD, cassette, phonograph [a known troublemaker], dvd, etc.) to the Marantz AVR with the exception of your 2 front mains; also disconnect your sub [bad RCA cable?) and surrounds. If the hum persists with just the mains, disconnect one speaker and test individually. At this point if the hum is still evident, grab a long 3 prong extension power cord and connect the AVR to a known electrical outlet on another circuit breaker than the one you were using. That way you can eliminate the circuit breaker & the electrical outlet itself. If that resolves the issue just keep adding one component at a time and test. If the problem remains, grab another AVR or receiver and test with just the mains. My money is on that Marantz AVR causing the problem. I could be wrong and it won't be the first time but nothing else makes sense to me. Good luck.

 

[avliner]

Hey Darien,

I also agree with Ponzio that ferrite cores won't solve this humming issue...
BTW, do you have a STB in the circuit? If so, un-plug it and give it a try, though.

 

[adk highlander]

He has been through all of your suggestions Ponzio and AVliner. The pre has the noise with just the amps connected with no sources. He has tried different outlets and everything else in the how-to-get-rid-of-a-groundloop guide. I had similar issues with that prepro and had my dealer give me another one which did the same thing. Many others here that owned the same unit did not have any issue. I recently upgraded to a Denon 4520 avr and am still using one of my amps to power the mains and the noise is now gone. (The AVR itself has transformer noise so I am getting a replacement but no noise through the speakers) After all I went through I feel his pain but don't have any further suggestions that he has not tried.

 

[darien87]

Thanks again guys. I have pretty much tried everything. The noise is almost gone now. Like I said you have to put your ear next to the speakers to hear it, but it's my OCD that won't let me just let it go. I want the noise gone COMPLETELY. I think this processor is just susceptible to this type of noise. But I'm hoping I can get rid of it. We'll see.

The weird thing is that adding that cheater plug was what seemed to drastically decrease the noise. But now I have removed it and the buzz is still quiet so it seems like it was just a coincidence. It's completely baffling.

 

[PENG]

Thanks again guys. I have pretty much tried everything. The noise is almost gone now. Like I said you have to put your ear next to the speakers to hear it, but it's my OCD that won't let me just let it go. I want the noise gone COMPLETELY. I think this processor is just susceptible to this type of noise. But I'm hoping I can get rid of it. We'll see.

The weird thing is that adding that cheater plug was what seemed to drastically decrease the noise. But now I have removed it and the buzz is still quiet so it seems like it was just a coincidence. It's completely baffling.

Now I feel better, knowing that the cheater plug was not the fix, it shouldn't be in theory. There must be something wrong with that particular unit, surely it is unlikely that you could get two like that but it is not impossible especially when both are open box items. I would just get a refund and go with something else. I don't understand why you are still hanging on to it if it obviously is bothering you.

 

[darien87]

Yeah, I'm pretty close to dumping it. Ii'm hanging on because I like everything else about the unit and everything else out there like the Yamaha CX-A5000 is 3 times the price. But I've already put my UMC-1 and Emotiva upgrade card up on eBay. I may keep the Marantz and the upgrade card and see about the XMC-1 when it comes out next year and then sell the Marantz.

 

[j_garcia]

Trade it in for a current model Marantz AVR?

 

[Rickster71]

I missed this
PM sent.

 

[Rickster71]

Now I feel better, knowing that the cheater plug was not the fix, it shouldn't be in theory. There must be something wrong with that particular unit, surely it is unlikely that you could get two like that but it is not impossible especially when both are open box items. I would just get a refund and go with something else. I don't understand why you are still hanging on to it if it obviously is bothering you.

I agree.
I wish I saw this before just writing darien a long PM
The cheater plug thing had me tilting my head like the old RCA dog.
I didn't realize both were open box items.

 

[darien87]

Trade it in for a current model Marantz AVR?

Brand doesn't matter to me. I've had good experiences in the past with Denon and Yamaha. But going from a Yamaha receiver to the UMC-1 I was amazed at how much quieter the UMC-1 was. Will a receiver have as low a noise floor as a processor? I also hate to pay for amps that I'm not going to use.

 

[j_garcia]

IMO, that's more about the specs than whether it is a Pre/pro or AVR. A good quality AVR likely will do just as well as a pre/pro in that department, but yes, I don't want the amps in there doing nothing either. Though I basically hadn't used the amps in my former Marantz 8300 for like 7-8 years and when I moved it to the second system I was able to use it as is.