Homeplug (PLC) inducing noise in my stereo.

[Calambres]

Hi there!

I'm quite new to this community so please excuse me if I'm placing this in the wrong subforum.

The fact is that I'm getting a very nasty periodic noise in the "Phono" section of my home stereo. After much debugging I finally discovered that this was related to a powerline Ethernet I've got at home through a couple of "homeplugs" a.k.a. PLCs. This only happens when "Phono" is selected, i.e.: the most sensitive input in my amp. No noise with the other higher level inputs as CD, AUX, etc.

The amp, in case you're curious, is a very good sample of Semi-High-End eighties technology, a venerable and very good sounding Cyrus ONE (Issue 7 "TOG") from 1989 that I have just recapped entirely with very good results (Nichicon MUSE caps), but the highly disturbing PLC noise is still there.

The noise is, as I've just said, a repetitive group of three loud clicks that completely disappear when I disconnect both PLCs. Before you ask: no, I cannot substitute the PLCs with either WiFi (no good reach to destination) nor Ethernet cabling as the infrastructure in my house makes this very complicated and expensive.

I've tried using an EMI filter at the Stereo power input with marginal success... the noise is somewhat reduced but very noticeable nonetheless. Of course, if I put the EMI filter at the PLC side, the amp noise disappears but the powerline Ethernet no longer works 

Is there anything I can make to sort this noise out?... As I've just said, I'm afraid I cannot discard the PLCs as the alternatives, at least the ones that I'm aware of, are not viable


Thanks a lot in advance and excuse my poor english   

[NiHaoMike]

Maybe hack the Homeplugs to run over telephone line?

[Calambres]

Hmmm... I'm afraid that at my home it is as difficult as wiring a direct Ethernet cable   

PLCs are the ideal solution in my case except for the noise problem. I need a way to filter that noise at the power input of the amp, but don't know how to do it properly.

[Halcyon]

I know you mentioned that your Wi-Fi doesn't reach where you want it, but have you considered "proper" access points like Ubiquiti? You'd be surprised at the performance difference between a decent commercial access point vs. consumer-grade garbage. I gave a mate of mine a spare Ubiquiti AP-AC-PRO I had, where he had no coverage before he now has almost perfect 5 GHz coverage.

[Calambres]

Wow!, that looks pretty expensive!

[phil from seattle]

I would take a look at getting WIFI to work - directional antennas on both ends can work surprisingly well.

You don't say where you are but if your power is split phase (like 120VAC in the US), you could try to arrange your homeplugs to one phase, the audio gear to the other and a filter in between.

Also, you could try to physically separate the homeplug from the audio gear if you already haven't.

[IanB]

You don't say where you are but if your power is split phase (like 120VAC in the US), you could try to arrange your homeplugs to one phase, the audio gear to the other and a filter in between.

Spain according to the flag. So no split phase there. It will be single phase 230 V.

In another thread, there was some comment about PLC putting noise on the earth wire. So one option might be to look at putting filtering around the earth/ground connections?

[Jeroen3]

You can indeed get filters for PLC. But that would probably reduce the performance.
Maybe an isolation transformer would work?

[Calambres]

Also, you could try to physically separate the homeplug from the audio gear if you already haven't.

I did, I did...

Spain according to the flag. So no split phase there. It will be single phase 230 V.

Yes, I'm in Spain. Single phase and 240V.

In another thread, there was some comment about PLC putting noise on the earth wire. So one option might be to look at putting filtering around the earth/ground connections?

How can I do that? 

You can indeed get filters for PLC. But that would probably reduce the performance.
Maybe an isolation transformer would work?

As I said in my first post, I already put an EMI filter with some success but it still was not 100% noise free. I've got an isolation transformer in my bench and I'm going to give it a try but I'm afraid that my stereo needs to be earthed. Otherwise it will be very noisy by itself besides the PLCs. If I add an earth connection to my isolation xfrmr the isolation will be immediately off as the neutral wire is already connected to earth in the house breaker box.

This is the EMI filter I've used, just one I've got lying around...

[Calambres]

My experiments so far:

- Pull out the earth connection: Just in case the noise is in the earth line. No difference.

- Isolation Transformer: No difference. The noise level is identical. With or without earth connection.

- Reverse the Live/Neutral: That is, turning 180º the Schuko plug. Very marginal success. Barely noticeable but noticeable nonetheless...

- EMI Filter: The noise is somewhat reduced but not eliminated.

Combining the last two renders the best solution available so far. Adding up the first two makes no difference at all. Still looking for a definitive solution using the PLCs.

Any other ideas?

[Jeroen3]

Get a filter made to remove PLC. They are different from your average EMI filter.

[Halcyon]

Wow!, that looks pretty expensive!

That's the great thing about Ubiquiti gear, the price is less than you'd think and is very affordable for home users (you just need to know a thing or two about networking to properly configure them).

To give you some idea, I buy the UAP-AC-PRO's for AUD$192.50 each (or AUD$936.10 for a pack of 5). The retail price won't be too much higher than those.

[Jeroen3]

You can go even lower with the price using Mikrotik gear. But you'll have to compensate with networking knowledge.

[Calambres]

Get a filter made to remove PLC. They are different from your average EMI filter.

I was not aware of such things. I'll investigate a bit to see what's available.

Thanks!

[stj]

there are serious moves at the international level to ban those things, they radiate over a huge distance and cause a lot of problems for radio operators.

[Lord of nothing]

  I use an Online UPS.
And screamed at my Dad until he replaced it with Lan and Glas Fiber.

How about Glas Fiber Cable? The are very Cheap on Ebay and Media Converter could be cheap to. I got mine for ~15€ from Ebay 1000Mb/s!

The Powerline crap transmitt on 2Mhz - 30Mhz and disturber CB communication. 

[Calambres]

You mean Fibre Optics Cable?

As I said before, I cannot route wires easily at home 

[Lord of nothing]

Yes.
Ignore when your wife is arguing around. 

[Richard Crowley]

Many (most?) turntables of that vintage had a grounding lug or terminal (or 3rd wire) to bond the chassis of the turntable to the phono preamp destination (preamp, receiver, etc.)  Does your (unidentified) turntable have a ground connection?

You could also try clip-on ferrite chokes around the phono cable. They will prevent RF from entering the preamp without affecting audio frequencies. 

You could also try shielding/screening the turntable to keep RFI out of it.  Perhaps lining the inside of the base with aluminum foil.  If your turntable has a top, perhaps lining that with conductive screen (like window-screen material).  Of course, the modern plastic screen material would not be suitable as it is non-conductive.

Phonograph technology was designed (and manufactured and lived and died) before the era of nasty RFI generators inside your home, so it is not surprising that they are so vulnerable.  If you want to use old-school phonograph technology alongside new-age wireless network tech, you must add extra protection.

[Lord of nothing]

The Powerline "Transmitt" the Data over an non Shield Cable.
That mean that:
a) Everything could receive there Noise even its run on an Accumulator.
b) The Noise also come truth the Powerline into every device.
The only Solution is replace the Powerline with something else. If your Neighbour use it get an Amateur Radio Licence and an nice AMP. 

[Calambres]

Many (most?) turntables of that vintage had a grounding lug or terminal (or 3rd wire) to bond the chassis of the turntable to the phono preamp destination (preamp, receiver, etc.)  Does your (unidentified) turntable have a ground connection?

Yes, it's got one and it is connected to a dedicated ground lug at the amp. If I don't do it, the hum goes wild!
My Turntable is a vintage Pioneer PL-200 with an Ortofon OM-20 cartridge.

You could also try clip-on ferrite chokes around the phono cable. They will prevent RF from entering the preamp without affecting audio frequencies. 

Good idea. As a matter of fact, the noise stops if I unplug the turntable from the amp. This is a relevant information that I forgot to put in here, sorry! 

If your Neighbour use it get an Amateur Radio Licence and an nice AMP. 

I've got both! 

[Richard Crowley]

... the noise stops if I unplug the turntable from the amp.

So that establishes that the RFI is entering at the phono input. 
So a power mains RFI filter won't really do much good (as you have demonstrated).

There are several places along the audio path where the problem could be attacked.
Putting clip-on RF chokes around the cable where it plugs into the receiver would be the simplest.
You could add RFI filtering (series choke, parallel capacitor) at the phono input.
Or same at the junction inside the turntable where the tone-arm wire connects to the output cable.

Or even some microscopic (and very light-weight) surface-mount capacitors right at the phono cartridge.
Note, of course, that anything you add at the cartridge end of the tone-arm will have to be re-balanced for weight, etc.

You have a similar problem to what radio stations back in the previous century were facing.
Especially radio stations where the studio was co-located with the transmitter and antennas.
They had to add RFI filtering to any low-level audio wiring (microphones, phono cartridges, etc.).

Of course, modern digital RFI is much worse because of the pulses generating infinite harmonics.
Rather similar to the jamming transmitters used by the Warsaw Pact countries back during the Cold War.

[Calambres]

You could add RFI filtering (series choke, parallel capacitor) at the phono input.

The RIAA phono stage at the amp seems to have a couple of such capacitors. Anyway, I'll give it a try.

Thanks a lot!