Question Speaker hum with Marantz SR7012

[Stupot43]

I've just purchased and set up a new Marantz SR7012 receiver. When we turned it on I found we had a hum emitting from all speakers. We never had this problem with my older amp which had been a Marantz SR7010. We eventually found that the cause of the hum was the 12v trigger to the subwoofer. Take the trigger out and the hum stopped.

Has anyone else with this amp had the same problem and if so how did they overcome this apart from removing the 12v trigger?

 

[dante01]

Hum is usually as a result of poor grounding, either in relation to the components and their internal grounding arrangements, the cabling and interconnections being used or even you homes own electrical wiring.

 

[Razor]

I have the same receiver and also found one day that I was getting a humming through all the speakers. It ended up being one of my banana plugs was not pushed in fully, it was only sticking out by a few mm.

 

[dante01]

Note that there's also a similar topic to this one here:
12v trigger cable ground loop buzz?


Also note if the trigger is being used in association with a sub then you should maybe check the connection from the AV receiver's sub pre out to the sub and or try a different interconnector between them?

 

[Stupot43]

Hum is usually as a result of poor grounding, either in relation to the components and their internal grounding arrangements, the cabling and interconnections being used or even you homes own electrical wiring.

But the only thing that had changed was the amp, everything else is the same. So I am assuming that it is a problem with the amp because it only started when the new amp was turned on.

 

[Stupot43]

I have the same receiver and also found one day that I was getting a humming through all the speakers. It ended up being one of my banana plugs was not pushed in fully, it was only sticking out by a few mm.

Checked all the connection and plugs. Everything is in as it should be and was still getting the problem.

 

[Slinkywizard]

The most common cause of this is a ground loop. You can usually eliminate it by ensuring that all of your connected gear is plugged into a single power socket. If your sub and your amp are plugged into different wall sockets, this could be the cause. If not, you’ll need to look elsewhere, but this is worth a try if they are indeed plugged into separate sockets.

 

[stevelup]

Doesn't your subwoofer have an auto-on-off mode that can be used instead of the trigger?

If not, try one of these:-

https://www.amazon.co.uk/dp/B000NVW...t=&hvlocphy=9045597&hvtargid=pla-420088663336

 

[DJ Dave]

I had an issue with a DJ monitor that was humming a bit and I just literally cut the earth off of the plug.

 

[stevelup]

Good advice, and not even slightly lethal.

 

[Stevehulluk]

I took the earth out of my kef kube 2 subwoofer that was humming, never hummed again. My electrician said it was the way the earthing is done in new build house, he said just disconnect the earth. Never had a problem and working perfectly :=

 

[stevelup]

That is terrible advice and dangerous.

 

[Stupot43]

Doesn't your subwoofer have an auto-on-off mode that can be used instead of the trigger?

That is what I've gone back to. I would still like to know why it started though. The only thing that has changed is the amp.

 

[stevelup]

Perhaps your old amplifier didn't have an earth connection (may have had a 2 pin power cable) and your new one does?

That thing I suggested in an earlier post for about a fiver will also solve your problem.

 

[Stupot43]

Perhaps your old amplifier didn't have an earth connection (may have had a 2 pin power cable) and your new one does?

Thought about that one and when we checked the new amp is still only using 2 pins, just like the older amp.

 

[rc789]

Hi all, I recently added an arcam p85 power amp to my sr7012. Received a mono cable from Amazon today, plugged it in and terrible hum. Didn't wait to check if it was all speakers but definitely came from the front. Unplugged and all back to normal. I have a rel t9i hooked up to the power amp using high level and lfe to the avr. As both amps are class a/b I've connected the black wire to the front negative on the power amp. Could this be having an impact? Am I okay to try disconnecting the high level connection, say at the sub or removing the black wire and taping the end and retesting with this hum?
First time using 12v and I've used remote in on the p85 and trigger out 1 on the marantz. Is that right?

 

[rc789]

And a side note, the new 4k belkin super fast hdmi cable caused major issues with the marantz, no issues on a pioneer sc-lx701.

 

[dante01]

And a side note, the new 4k belkin super fast hdmi cable caused major issues with the marantz, no issues on a pioneer sc-lx701.

If referring to Belkin's 48G cable then you wouldn't need it anyway. The bandwidth associated with HDMI version 2.0 is only 18 GB/s so having a cable with the ability to convey more than this is utterly pointless unless you've HDMI version 2.1 equipped hardware and if conveying 8K UHD video via it. Ultra High Speed HDMI cables are not required for 4K UHD and have no associated benefit over High Speed cables when being used in setups who's equipment is HDMI version 2.0 as opposed to version 2.1.

 

[rc789]

Understood. Just thought I'd put it out there.

 

[rc789]

Any advice on the hum?

 

[HenkL]

Stupot43, did you solve the problem?

I have exactly the same problem with the SR7013! I exchanged it for the SR7010. Exactly the same connctions!

 

[Stupot43]

No, I didn't solve it. I had to revert to the original method of the sub picking up any low frequencies to turn it on. Not perfect but it works.

 

[Hixs]

Maybe its quite a common issue? I too suffered from buzzing when I hooked my Arcam A38 up to my 5010. I worked fine to begin with but after a week or two it just randomly starting buzzing. I tried to live with it, but ended up buying a Beresford speaker switch.

 

[HenkL]

Of course generally, but maybe a bit more to Stupot43.


Think we have about the same setup. My settings are that I send everything lower than 80 Hz to the subwoofer, so also for CD music. But playing at a low level or acoustic music, the subwoofer won’t switch on always. So I really like the trigger mode.


But like stated already in this thread, hum/buzz is generally caused by an earth/ground loop.


It looks like that the coaxial cable to the subwoofer and the 12V trigger signal use the same ground.


Thinking this over, but I didn't measure it, I did decide to cut the trigger cable and to isolate the ground signal.


Works perfectly here, but I can’t guarantee in general!

 

[tta]

Hello! I'm new to this forum and I would like to ask you a specific question about the CA 752bd you recently sold. Sorry but I'm not allowed(?!) to reply to the actual thread, so I'm asking here. You referred to a disc that would work to keep BD all regions. How do I acquire such a disc, as a friend needs to unlock her modded unit of same? Thanks!