Help! I Can Hear Weird Background Sounds Through My Speakers?!

[Shakey]

Hi All,

First time poster here! 👋 I am hoping someone may be able to offer some help or advice concerning a strange issue my hifi has just developed. When my amp is set to the phono stage, and the turntable is plugged into the amp, I get a weird eletronic tone that appears every minute. I don't think I can upload videos here but you should hopefully be able to view a short clip via this link.

In summary, I have just re-located my hifi back to a spot in my living room where it used to live before I had kids, but I have never heard this sound before. Nevertheless, re-positioning the system is the only thing I have changed, other than perhaps where the hifi is plugged in. I have the amp and turntable plugged into the same extension cable and I have unplugged my other separates leaving just the speakers and sub plugged in to the amp. When I unplug the turntable interconnects from the amp the sound disappears, but if the interconnects are plugged into the amp's phono input, but not plugged into the turntable, the cables seem to pick some radio interference plus the noise returns. For what it's worth the interconnects are not super expensive ones but they are of good quality and as I say, I have not experienced this issue before with them. Furthermore, this issue doesn't occur when using the other inputs on the amp. I have also tried turning off my router in case this was the source of the tone, but the issue persists.

Many thanks in advance for any help you might have, this was supposed to be the first step to getting the hifi back up and running properly and it feels as though I've fallen at the first hurdle

 

[Al ears]

Odd. Is the turntable earth wire attached?
First thing I would do is plug the amp into a different mains socket to the one the turntable is powered from.

 

[Shakey]

Thank you for the reply! It is attached and I did think it could be the earth wire initially (still not ruling it out either). As for the mains plug, the sound will occur if I've only got the turntable plugged into a wall socket and with interconnects plugged into the amp's phono input, but not connected to anything at the other end. So this makes me thing it's not the turntable at fault. Furthermore, if I unplug the interconnects from the phono stage then teh sound goes away. So it seems as though the interconnects are acting as an aerial somehow?

 

[abacus]

Try removing the ground wire in case it is causing an earth loop.
It's possible that the grounding in the cables has become open circuit during the move (Unplugging and plugging back in), so try another set of leads first. (Amazon basics are fine)

Bill

 

[Shakey]

Cheers Bill, will do! Got a good list of things to try later on now. I will report back!

 

[Jasonovich]

As per the suggestions above, if all fails. I would change the phono interconnects with new ones. Good luck.

 

[Shakey]

A quick update as just tried a couple of things as below:

1) I tried different interconnects (plugged into amp's phono input but not the turntable) and sound remained.
2) I removed the interconnects from the phono input altogether, and the sound remained but was much quieter (barely audible)
3) I set the amp to one of the line level inputs and cranked the volume right up. I couldn't hear the noise

I guess this suggests it might be the amp's phono stage at fault?

 

[Gray]

I guess this suggests it might be the amp's phono stage at fault?

No, it doesn't.
Phono stages give much higher gain than line inputs.
You will always hear more noise from open phono inputs, than you will from line inputs with the volume turned right up.

That's not an answer to your issue, just don't go thinking your amp is at fault.

 

[Shakey]

No, it doesn't.
Phono stages give much higher gain than line inputs.
You will always hear more noise from open phono inputs, than you will from line inputs with the volume turned right up.

That's not an answer to your issue, just don't go thinking your amp is at fault.

Duly noted!

So, next update. I just went around the whole ground floor switching off each wall socket individually to see if I could find what was causing the sound. I switched off everything except for a fridge in the utility as I couldn't easily access the socket. However, it did mean that all computers, peripherals, the router and smart devices were switched off at the wall sockets. The sound remains

Any other suggestions? I'll give anything a go! Thanks again for all of the input so far

 

[Shakey]

Another update! I've cracked it! I moved the hifi back to its previous position and the noise went, I returned it to the new position and the noise came back. I was puzzled as I had previously switched off all of the mains powered electronics, so they shouldn't be causing the interference. Then it occurred to me, that we had a small battery powered thermometer that sits just outside a nearby window that transmits to an indoor/outdoor temperature display in the room. I brought the transmitter inside and placed it next to the amp and the sound came back louder than ever, but with the batteries removed it went!

So it turns out that just by moving the hifi about 5" along a wall it brought it close enough to the external transmitter to cause a problem.

I feel a bit daft now but very pleased to have got to the bottom of the issue. Thank you all so much again for your time and suggestions!

 

[good_enough]

Another update! I've cracked it! I moved the hifi back to its previous position and the noise went, I returned it to the new position and the noise came back. I was puzzled as I had previously switched off all of the mains powered electronics, so they shouldn't be causing the interference. Then it occurred to me, that we had a small battery powered thermometer that sits just outside a nearby window that...

Nice one, but worrying a little - there are lots of RF sources in a house from LED lights to Hive thermostats to smart meter indoor units, and it would be nice to think our kit was immune to it all! Obviously not!

 

[Shakey]

Indeed, of all the electronic devices in the house though a little wireless thermometer thingy (that’s not even inside the house) was the last thing I considered!