Vibration on the back of the AV receiver

[peterbund]

Last week I bought a new AV receiver (Sony STR-DH590) because I bought a new projector. If I touch the back of the receiver I fell some vibration. Is this normal? During watching a movie yesterday with headphones which were connected to this AV receiver I also felt for a moment some electricity in my headphones. It was like static electricity. Is this normal too? I wear often headphones (mostly the ones over ears..yesterday I wore those that go inside the ear) and I never felt this quick electricity.
I contacted official Sony repair office in my country and the person there said that this two things that I mentioned are normal.

 

[Researcher]

Vibration could be caused by a fan starting up.
I don't think you should be getting any static electricity though as everything should be grounded.

 

[Joe Fernand]

Many folk ‘feel’ the Vibration effect with Double Insulated (no earth pin on the Mains plug) devices - if your device does have a 3-pin Mains cable and you feel this effect you should have your Earth checked ASAP.

Headphones - very odd to ‘feel’ rather than ‘hear’ any effects, could you have been touching another chassis at the time?

Joe

 

[peterbund]

I dont think it is vibration from the fan. I would feel it differently I guess.

Earth checked? What do you mean with that? Acutally this Sony AV receiver has that kind of cable: 2 Pin Mains Cord
Yes I touched the chasis of the projector and mounting it to the closet. I was also touching the AV receiver because I also put it to the closet. Both I put on TOP of the closet not inside.
I use them after that (without headphones) and everything worked without some problems with signal..

 

[Joe Fernand]

If you have a unit with a 3-pin Mains cable and you felt a tingle you need to have its earth checked for continuity straight away by someone qualified to undertake the test.

Does your AVR carry the Class 11, Double Insulated (Square within a Square) Logo - Appliance classes - Wikipedia

Joe

 

[peterbund]

As you can see on the picture I give you I have different Mains..it is not 3-pin. So what I need to do now if something at all?

 

[Joe Fernand]

Which Sony AVR do you have?

Joe

 

[peterbund]

Sony STR-DH590

 

[noiseboy72]

So what you are feeling is probably actually coming from your projector. It's basically parasitic earth noise that's got onto the audio amplifier ground via the HDMI. This is not at all uncommon and in fact, I get it from my laptop if it is plugged into my TV. It can be quite high frequency functional noise from the power supply and is the same thing that can cause the zinging and buzzing on some audio connections from laptops into sound systems.

It's not dangerous, as it's very high impedance, low voltage and low current. It's just a nuisance if you can feel it in every day use. I would imagine that when you felt it through your headphones, it felt more intense, as your hands get quite de-sensitised to the sensation, but other skin does not!!

Not a lot you can do about it. Some user manuals actually mention it - sometimes described as a "roughness". I had a Roland HDMI vision mixer at work that did exactly this and could be quite painful if you rested your wrist on the casing. We ended up fitting foam arm rests to cure the issue.

 

[peterbund]

You talk about the vibration from the back of the receiver or about this short electricity/static electric in a headphones?
I feel this "electric vibration" on the back of the receiver also when the receiver is not connected to a projector or to any other device. I don't use headphones now anymore..I connected speaker to receiver and in terms of sound and video that I get from a projector and speaker everything looks ok. Just this vibration on the back still exists. It is actually far less noticable if I put something on the top of the receiver...

 

[noiseboy72]

Yes, it's just slight electrical noise. Nothing to worry about. The vibration might be from the transformer - they do vibrate slightly, and putting something heavy on top of the amp is enough to dampen it out.

 

[peterbund]

What was then this fraction of the second electricity in one side of the headphones (i used the ones that goes in ear)? I asked one other person and it said that it could be because the connector of my headphones was dirty. And actually I watch it and it really had some like dry dirtiness on it.

 

[peterbund]

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