Humming Supercap Caused by LG TV


I’ve changed my TV to an LG OLED and it’s causing my Supercap to produce a loud hum. As soon as I turn on the TV the humming starts and it stops as I turn the TV off. The humming gets louder if the TV works a little harder and it gets softer when the TV has less to do.

Does anyone have any suggestions how to stop or reduce the humming? Perhaps some sort of filter to stop the interference being introduced to the mains by the TV. Many years ago I arranged for the lounge to have it’s own electrical circuit but that’s the same circuit used by the TV.

Any suggestions would be greatly appreciated as I don’t want to change the power supply or the TV.



Have a look here

Are you able, if not done already, to put the SuperCap and TV on different house mains circuits?

I should say I have my Naim and LG OLED TV ultimately on the same consumer ring circuit, I don’t experience the problems you do… compared to my previous plasma TV I find the LG totally benign, but I realise that doesn’t help you.

I think the issue may depend on whether your TV model incorporates PFC circuitry in the power-supply, but alas you won’t know that. I believe it is EU law for all AC to DC switch mode powersupplues above a certain current draw.

Thanks for the link. If the Supra DC blocker was available in the UK, I would have tried it out.

One retailer I contacted wouldn’t sell me any of their mains conditioners or power filters as, in their experience, they don’t solve the issue.

This isn’t an easy problem to fix!

Careful… do a try before you buy… if it is a power factor (PF) issue, you may find conditioners don’t do much good. A DC blocker might, just ensure it’s rated for the correct current of your system…, but depending on the underlying issue, that might not even resolve the matter…

That’s a good point about ensuring the DC blocker has the correct current for the UK as that model isn’t available.

I used a long extension lead today to plug the TV in from a different consumer ring circuit. This reduced the humming by about 90%. It’s a pity my wife will probably object to me running an extension cable out of the lounge, along the hall and into the kitchen!

In the longer term, it look like an electrician will have to put in a new ring circuit just for the TV.

Good to hear it’s better on a separate circuit. It’s well worth getting a dedicated supply just for the Hi-Fi

As James says, a dedicated mains circuit for the HiFi is always worthwhile. The gold standard is to run it from a small separate consumer unit, with heavy duty (preferably 10mm) cable. In your case, I wonder if shielded mains cable would be worthwhile.

Thanks for your suggestions. If I’m going to have an electrician run a dedicated mains circuit, I may as well ensure it’s done properly.

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The humming continues unabated and it’s driving me a little crazy (countless weeks at home probably isn’t helping either).

Has anyone tried an Airlink conditioning balanced power supply? Apparently, balanced power works best if all of the connected equipment in a system are fed from the one balanced source. They recommend adding up the total maximum power of the connected units, doubling it and then selecting a supply that is equal to or greater than that figure. This is in order to make sure that there is no possibility of power compression affecting the dynamic performance.

That being the case, do you know the the total maximum power for a supercap (for the 52), XPS DR (for the NDS) and a NAP300?

I appreciate a lot of you will want to tell me the balanced power supply may have an adverse effect on sound quality but, right now, that needs to be balanced (no pun intended) against removing the humming sound, which really needs to go!

Hi David,
This post might help:
Airlink BPS installation

In the old forum there is a long thread called
“Suffering from those transformer hum blues?” which runs through the full history and benefits of installing one of these beasties. A quick phone call to Airlink will soon sort out the most appropriate model for you. I was recommended a 3kVA one but went for the 5kVA because the cost difference was so small.

Quite a few Naim owners have an Airlink BPS installed due to transformer hum.
Alternatively, you can buy a dc blocker (others can advise their preference here) or even put your TV on one of these APC uninterruptible power supplies, as used for small home computer computer networks, as this decouples the TV and other devices that are powered through it.

Best regards, BF

Hi David, I’m using an Airlink BPS for one of my system. Works very well, no more hum and cost is not too bad.

I tried an airlink transformer and it did not reduce hum for me at all. They obviously work for some people but are not a cure all.

Thanks for the advice. I’ve ordered an Airlink Balanced Power Supply and hope it works.

Hi David, did you finally solved your problem at the end? I saw your post because I have experienced the same issue when I bought a new TV OLED and my amplifier was doing a very concerning sound. I have finally decided to return it and change for a TV QLED, since the problem is completely gone. Hope this would help other users.

I bought an Airlink ASF3000 transformer which has stopped the Naim power supplies from humming. Sometimes the transformer is virtually silent but at other times it hums! At its loudest, the volume of the humming from the transformer is much softer than with the Naim power supplies, but it’s not the perfect outcome. I’m going to contact Airlink and see whether there’s anything that can be done to reduce or stop their transformer from humming.

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