Noise from Powerline Adaptors

surfguy13

Just wondering if anyone has had any issues with noisy amps as a result of installing powerline adaptors?  I installed a pair of TP-link 1200 powerline adaptors to provide a fibre signal in an upstairs room.  These units use the electrical circuit in the house to carry the fibre signal as I understand it.  They work perfectly but................the router, to which the 1st powerline adaptor is hooked up, is downstairs and about 10 metres from the room in which I have amps set up.

I noticed a sort of pulse/electrical noise coming from the amp and initially didn't associate it with the powerline adaptors so assumed it was an amp issue.  Because it was a pulse noise rather than something I would expect from an old valve amp I decided to check power connections first, isolate the amp from effects etc etc.  Didn't make any difference and the noise was still there.  Even when the cvolume on the amp was truned to zero.  So, tried turning off the powerline adaptors and the noise immediately stopped.  So that's definitely the source.

I can't think of any solution to this problem although by moving the amp much further away from the adaptors the noise eventually stopped; so it seems to be proximity to the adaptors rather than something that is being generated within the elctrical system within the house.  Looking online it seems to be a common problem but can't see any advice re how to prevent it happening.

Just wondered if anyone had experienced this before or possibly had any ideas how to stop it happening?

mynamesnotbob

Yes, the power line adaptors effectively are just radio transmitters that push it to cable rather than air.  Every single socket is then infected with this radio interference, some devices cope others do not. I don't have it with any guitar stuff, but I do have it with the sub in the living room. I have no removed all the power lines and gone hardwired Cat6. The problem I had was the amp for the TV was under the stairs along with everything else and a power line adaptor taking ethernet to the TV's - it seemed the combination of noise through the cables, combined with it being radiated caused the noise. Pluging into a UPS and being next to it was fine, being on the mains but not next to it was fine - both together = bad

But you could minimise, but none are guaranteed, steps I took to minimise:

• Don't push traffic down the power lines, not really practical.
• For the power cables of the effected units, use a ferrite sleeve - any cheap ones will do.
• For the input signals, again ferrite sleeves
• Move the device to a surge protected extension lead
• Move the device to a UPS - this works, but who wants an amp on a UPS, hold on thats not a bad idea...

By their very nature power line adaptors inject noise into the mains, depending on proximity to the devices, age of wiring, shielding on wiring, other devices etc it gets worse

Try ferrite sleeves and a surge protector first.

Powerlines are horrible dirty things that don't get enough RF interference testing - thats all manufacturers IMO

surfguy13

Really appreciate that detailed response @mynamesnotbob, really good to understand the problem a little more. 

The weird thing is that it's not affecting all the sockets on the ground floor.  I can get a clear signal with no noise in the kitchen and in the conservatory but these are both further away from the powerlines than the room in which the amp is located.. 

I have to be honest and say that I've never heard of ferrite sleeves but I will order some today in the hope that it may reduce the problem.  When you say use ferrite sleeves on input signals would this include the power supply for the effects (multi power supply)?  I have a surge protected power supply so will get that hooked up too, great tip.

I'm guessing the noise generated by the powerlines won't damage the amp? 

surfguy13

Just been looking at ferrite sleeves on RS and there is a hell of a lot of options!!!!  Just measured the power lead from the amp and that's 7.44mm but not sure which sleeve is the right fit?  The lead from the power brick is 3.59mm so much narrower.  This is the page I was looking at:

http://uk.rs-online.com/web/c/passive-components/ferrite-cores/ferrite-sleeves/?cm_mmc=UK-PPC-DS3A-_-google-_-1_UK_EN_G_Ferrite_Cores_Phrase-_-Ferrite_Sleeves-_-ferrite sleeves&matchtype=p&gclid=EAIaIQobChMIsYzVx8vZ1gIVVdwZCh1MJgZREAEYAiAAEgIOCPD_BwE&gclsrc=aw.ds

Any idea which sleeves would fit a 7.44mm cable and a 3.59mm cable?  Or, should I fit a sleeve only to the extension cable that feeds both the amp and the power brick?

mynamesnotbob

It's a minefield, and not consistent thats why I learnt to hate them, but they do serve a very useful purpose!

If it was me, I would get:

http://uk.rs-online.com/web/p/ferrite-sleeves/7740639/

1 to go straight over the mains cable, you will have to squeeze tight but it won't move

Then use the same diameter (or get http://uk.rs-online.com/web/p/ferrite-sleeves/1232480/) for the power brick cable, and loop it over twice like this:



Or go for a selection pack like this: https://www.amazon.co.uk/Dreamtop-Clip-Ferrite-Suppressor-Diameter/dp/B01MG8GQ1F/ref=sr_1_1_sspa?ie=UTF8&qid=1507211188&sr=8-1-spons&keywords=ferrite+clip+on&psc=1

The trouble is you are never sure which one is injecting the noise, it could be mains cable, it could be a signal cable picking it up etc etc - so being able to experiment helps.

When I was isolating the sub I put them on the amp power cables, the sub power cables, the amp line output, the line input on the sub, on the wiring in the wall hidden behind the faceplate. To this day I don't know which one it was that fixed it, but it all of them together dropped the noise massively.

Noise from the power line shouldn't damage the amp, it's just a noise, but will be annoying for you. The correct answer is to remove the problem like an earth loop on a pedal board, but for both cases that not always practical.

I will put the disclaimer that none of this may work - RF interference is a tricky thing to isolate. So if there is an easier option of moving to a different plug that is less effected, it's worth looking at. I found an extension cable from another room worked in isolating it, but then I had 10m of extension cable running across a room, so not really practical 

surfguy13

Once again, very many thanks for taking the time to run through this, really appreciate it.

I will get the sleeves you suggested from RS but might also consider the Amazon selection pack if the RS sleeves make a difference.  Great to know which ones to go for!  Normally use RS as they are relaible and customer service is great.

It hadn't occurred to me to install a sleeve on the wiring behind the faceplate but that makes a lot of sense.  I can cover all the bases with the Amazon pack, cheap enough and if it doesn't work they'll probably come in handy in the future.

I totally understand that the above suggestions may not work but it's certainly worth a try and the cost is peanuts.  I installed a Belkin surge protected extension lead with an earth and unfortunately there was no difference but in conjunction with the sleeves you never know.

I did consider an extension lead but it means the doors can't be shut which is a pain.  When plugging the amp into sockets in the two rooms off the room with the amp there was no noise at all so if the worst comes to the worst I can either ditch the powerline adapters or maybe run an extension cable through one of the walls, one is block but the other is just a stud.

As you say, these adapters are a huge pain but they are very handy indeed!!    Thanks once again @mynamesnotbob ;and I will let you know how I get on.

Gagaryn

If you decide to go at the problem the other way you could ditch the power line and use modern Mesh WiFi like the Google one which work much better than traditional WiFi extenders. This page has a good explanation of how they work  http://www.trustedreviews.com/opinion/mesh-routers-whole-home-wi-fi-explained-2953740

surfguy13

Gagaryn said:

If you decide to go at the problem the other way you could ditch the power line and use modern Mesh WiFi like the Google one which work much better than traditional WiFi extenders. This page has a good explanation of how they work  http://www.trustedreviews.com/opinion/mesh-routers-whole-home-wi-fi-explained-2953740

This is REALLY interesting and I had no idea that a Mesh system was even out there let alone an option.  It sounds almost perfect with few if any downsides.  I will try the ferrite sleeves and see if I can reduce the noise but if that fails then this is a very real option.  Really appreciate the heads up!

bean7

FWIW I experienced this too - and found that powering the amp via a surge protected Ikea extension socket seemed to filter out the noise.

surfguy13

bean7 said:

FWIW I experienced this too - and found that powering the amp via a surge protected Ikea extension socket seemed to filter out the noise.

Yeah, I tried this first as @mynamesnotbob suggested but unfortunately it didn't make any difference.  Bummer.  However, last night I powered the amp up with both powerline adaptors switched on and........no noise!!  Bloody weird.  I'm going to install the ferrite sleeves anyway in the hope that they reduce the noise or possibly even get rid of it altogether.

Andyjr1515

Hmmmmm.....I've started getting some really intrusive buzz on my home practice amp.....and thinking about it, I've relatively recently started using powerline adapters. 

When I get a moment I'll see what happens if I unplug them all....although don't expect me to be able to post a response after I've subsequently f****d up my home network

DartmoorHedgehog

I think a lot of it just down to luck - most devices don't seem to be affected in my experience.  I use a pair of powerline network adaptors and only ever had one case of interference with an audio device - a Blackstar HT20.  Various other amps around the house seem to have no problem with it (various HiFi amps and radios, telly, Blackstar ID Core, Orange Rocker 30).  I haven't bothered doing anything about it because I don't have the HT20 any more, but at the time it was pretty annoying.

surfguy13

DartmoorHedgehog said:

I think a lot of it just down to luck - most devices don't seem to be affected in my experience.  I use a pair of powerline network adaptors and only ever had one case of interference with an audio device - a Blackstar HT20.  Various other amps around the house seem to have no problem with it (various HiFi amps and radios, telly, Blackstar ID Core, Orange Rocker 30).  I haven't bothered doing anything about it because I don't have the HT20 any more, but at the time it was pretty annoying.

 I have not had issues with other devices so far either.  Just the one amp.  It's a 1963 Ampeg guitar amp and so much older technology so I wonder whether that makes it more vulnerable?  However, it is perfect working order and about as quiet as a valve amp can be.....assuming the powerline adaptors are unplugged!!

I did contact TP-link about the problem and to be fair they were quite responsive.  It was escalated to a 'senior engineer' (in China) who responded with this today:

We've received some cases about noises on speaker devices like yours.Since HomePlug AV/AV2 protocol use the same frequency band with some other devices, Powerline products may interfere with devices such as lighting systems that have a dimmer switch or a touch-sensitive on/off feature, short wave radios, cable television system, VDSL devices, speakers, or other Powerline devices that do not follow the HomePlug AV/AV2 standard.
For now we cannot solve this 'cause it's not only on the powerline device but also need other manufacturers to modify their speakers/amplifiers etc.
But here's a method you can have a try:
Please download the tpPLC utility on our website and install it to your PC.
Connect your PC to the powerline unit and run the utility.
Move your mouse over the device icon and go to Advanced menu-Mode,try to enable the Lower interference mode to see if this help (this will decrease the rate in powerline so the performance will be affected)

So, basically they are saying they know all about it and there's sod all you can do about it other than accept that the only possible fix/semi-fix is to reduce the output/range of the powerline adaptors.  Oh yes, and of course blame 'other manufacturers' because they haven't modified their equipment!!!!!!!!!  Priceless.