Very strange buzzing when connected to a PS3.

[Everso]

Hi all,

I have a most unusual problem manifest it's self. I have a Sherwood AV amp and a nice new PS3. And this is where the buzzing comes in. When the PS3 is plugged into the TV with the audio connected to the RCA inputs all is fine.

I have recently purchased a 10M HDMI to DVI cable so I can connect it to my 22 inch Samsung computer screen for when I want to play and my wife wants to watch the TV. It all works fine for about 10 minutes when the amp starts to have a massive buzzing. Unplugging and re-plugging the HDMI cable will get me another 10 minutes or so but it is quite consistent in the way it is behaving.

The noise is about the 50Hz so I am suspecting it is a mains related issue. The Amp, TV and PS3 are plugged into one socket and the Screen and computer it is attached to (via RGB) is on another so I am wondering if I need to isolate them somehow?

Any one got any ideas what could be causing this and what I can do about it.

I can get exact make and model numbers of all kit if anyone thinks that relevant.

Thanks for making it this far and a look forward to your replies (hopefully).
Everso

 

[Mark.Yudkin]

Since it's a 50Hz hum, its likely an earth loop. There are two typical "causes", which first need to be checked for a diagnosis:
1) the computer. Disconnect it completely from all other components and retry. Presumably thius returns you to the state you already said was OK, but maybe you added something else too?
2) the TV feed (cable, satellite). If disconnecting the computer didn't resolve the problem, also disconnect the TV's inputs from the back of the TV and all separate cable / satellite / whatever receiver boxes and retry.

If removing the computer works, reconnect it and try 2) by itself.

Post back the results, including exactly which cables needed to be disconnected, so we can address the resolution (1 is harder, 2 is easy).

As for power sockets, sometimes using the same socket and a multi-way power adapter can help. But let's first test the likely.

 

[Everso]

My thoughts were earth loop - it does sound like a classic. The strange thing is that it will be fine for about 10 minutes and then start the hum. I disconnect the DVI lead and re-connect it and I get another 10 minutes of perfect sound.

I have also removed the lead from the headphones transmitter output (RCA pass-through) to the amp and the noise stops completely. So it looks like this is where the problem lies (though the 10 minute gap is still strange).

Anyone got any opinions on the RGS Ground loop isolates like this on e-bay?

PRO DJ GOLD RCA PHONO GROUND LOOP ISOLATOR TO PREVENT UNWANTED HUM OR NOISE | eBay

I can live without the connection to the amp if that’s what it takes to fix it but it would be nice if I can get it because it would allow me to have sound through the HiFi when I have it playing on the big screen.

Everso.

 

[Mark.Yudkin]

This specific earth loop isolator option is the last resort, which probably won't even work in your case as it's for phono leads, whereas your problem is probably in the HDMI connector or the RF feed(s).

Hence, before adding a device that solves some problem, I reckon it would be worth while finding out if you even have the problem it addresses. The headphones transmitter is probably the "other half" of the path to ground, but it's probably not the cause.

Just to console you, a ground loop problem can be safely resolved, and I'll help you get there, but a sure diagnosis is essential. Perhaps you could answer my questions from my last post?

 

[Everso]

Hi,

thanks for the reply. Good to know that this will be resolved .

The headphone transmitter is from this

Buy Datel GameTalk Pro 2 Wireless Digital Gaming Headset for PS3 at Argos.co.uk - Your Online Shop for PS3 Headsets.

It plugs into the audio/video output on the PS3 and does not have any eternal power. It does however have a pass through socket on the back and I believe this is where the issue is. I have plugged in the provided AV lead (as you are intended to) and then the phono connection from that to my HiFi.

When I unplugged it the humming stopped so that does seem like a humming - if not smoking gun. This is why I was wondering about the isolator I listed as it goes to the HiFi though phonos.

The thing that is still confusing me - and no amount of searching is helping with - is why does it take 10 minutes of use or so before the hum? From what I found the hum is normally there as soon as you plug the offending device in.

Everso

 

[Mark.Yudkin]

Good to know that this will be resolved

But only if you answer the questions, e.g. those from post #2

If the cause is indeed the Datel GameTalk, and it's a noise that only comes after 10 minutes of usage, then it's likely either the Gametalk or the PS3. You could possibly determine which by using the headset with the PS3 but not the amp, to discover if the hum occurs through the headset, and contrasting this with connecting the PS3 to the amp and not using the headset. Of course, there are a lot of if's, as there's no real evidence that the PS3 and headset are implicated at all, other potential causes not yet being excluded.

I have a tendency to like to try doing things in order, one at a time, rather than hopping around trying many things simultaneously in the hopes of possibly stumbling over something and switching mid-track. Could we try this approach ?

 

[Everso]

You could possibly determine which by using the headset with the PS3 but not the amp, to discover if the hum occurs through the headset, and contrasting this with connecting the PS3 to the amp and not using the headset.

Ok - I gave this a go.

With the headset in and not connected to the amp = no hum.
Headset and amp connected but not turned on = hum through headset.
Headset and amp connected with amp on = hum through amp.
PS3 connected to amp without headset = hum through amp.

The results above are the same if the PS3 is connected via HDMI to the DVI lead or HDMI to HDMI into the TV.

Given that there was no noise before the PS3 was connected and this was the last component it very much looks like the PS3 is allowing some sort of a ground loop with or without the headset in use.

I think am going to order one of those isolators from e-bay and put it on the phonos from the pass-through and see if it helps, it's only a few £ so I figure not too much to lose. I'll post back what happens for the benefit of any who are searching after me with a similar issue.

Thanks everyone for the help and advice you gave.

Everso

 

[Everso]

Sorry for the double post but this is for those who are searching behind me. From some other goggling I came across the suggestion that it might be poor connections causing resistance and thereby the ground loop. So I removed all connections from the audio of the PS3 to the inputs of the amp – cleaned where possible and re-plugged making sure everything was firm and as good a connection as possible.

Result – problem solved. No noise or hum no matter what is set or turned on/off.

Once again thanks for the help. For anyone searching that comes across this thread – good luck and I hope this helps

Everso.