Audible computer noise over network when using Powerline Adapters - Aqua La Voce S2 + Ampsandsound SE-84

Hey all, I have a maddening problem. I’m hearing very audible computer noise through my headphones when using Roon. Specifically, this seems to correlate with controlling Roon with my Mac desktop.

Here is my setup:
Modem/router connects via ethernet to :arrow_right: powerline adapter (sender) :arrow_right: powerline adapter (receiver), which connects via ethernet to :arrow_right: Innuos Zen music server, which is both Roon core and local file storage/player. USB out to :arrow_right: DAC. RCA out to :arrow_right: amp and then out to my headphones.

Before, I used a mac mini as just roon core and stored my local files on a NAS. The mac was located in the same place and same network connection as is the current Innuos Zen.

With the mac, I was hearing a lot of computer noise through my headphones when interfacing with Roon. It sounded like static, a sort of scratching sound. Whenver I would I would move my mouse, scroll, click a button or especially when I would start playing a track, I would immediately hear static-like noise associated with that action. I assumed this was due to my crappy mac, so I purchased the Innuos Zen thinking it would surely mitigate the noise. WRONG! I still hear the same noises!

The Zen is running Roon core. I control Roon via a Mac book pro used solely as remote over wifi. Can anyone tell me what is going on and how to fix it?

Have you ever tried to (at least temporarily) replace the power line adapters, with a plain ethernet wire ?

My best guess is that they are the ones to blame. Had something very similar, a few years ago in my home studio (have to admit : that system was not connected to any ground, back then). The mere function of those adapters is to inject, or ‘pollute’, the mains wiring in your house with RF signals. Not a very neat thing to do, I’d say. My assumption (…) is, that either one of your power supplies, or the connecting wires are picking up those signals, and somehow pass them through in the audible band… Not easy to resolve any of those situations…

If solved with ethernet wire : best solution will be obvious :slight_smile: . But I understand you cannot always run ethernet, everywhere. My solution was, to invest in a decent WiFi solution (ubiquity mesh in my case)

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Power line adapters can work great or…
Here’s a thread from the naim forum with the OP asking about network noise.

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Appreciate both your comments so far. I did wonder about the powerline adapters. But I’ve used them in another house and they worked fine, no audible noise. Now I’m in a different house so perhaps the wiring is worse here, or some other situation being exacerbated by the adpaters.

I’ve bought a 100ft ethernet cable to test the theory. I guess we’ll see what happens…

Regarding mesh wifi. I know there is a lot of discussion using this with audio. In a nutshell it works well? Just as well as hardwired? Any drawbacks (besides price)?

Many thanks.

I wouldn’t say it worked as well as wired but it can work well. But like all these technologies it’s not guaranteed.
I had generations of power line adapters increasing in speed and features over the years. But I’ve replaced mine with a mesh and it is much better, for me.

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It´s almost funny, how the wording in that Naim post is similar to mine :slight_smile: . Trust me, these were my own words, I have never read anything on a Naim forum…

Anyway, re the mesh question. Yes, there is a lot of discussion, and probably rightfully so.
I guess the results will heavily depend on the circumstances/environment of your specific house, as well…

I can only speak for my own situation, I have not tested other mesh equipment.
I am extremely, very happy with my Ubiquiti Amplifi set. It is very easy to use, and as stable as one can wish for. The ease of use is both its forte, and its weak point :wink: .

In a way, it is very similar to Roon Rock. Set, forget, and never look back. Want to make an exotic setting ? Sorry, this is not for you.

(This is in a larger, 2 story building, with a whole lot of reinforced concrete. I still have proper WiFi outside, some 75 meters away from the nearest router at least. Rock solid, way fast enough for music purposes.)

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Cool, thanks. Is there a reason you went with Ubiquiti vs another brand or type? I hear Orbi get thrown around a lot.

That post you made (Naim or otherwise) was very clear and helpful BTW.

I get my long ethernet cable next week so will know more then.

thanks

Summary

Doing a bit more research. Came across some info regarding inserting a couple fiber media converters (ethernet to fiber > fiber back to ethernet) to isolate noise issues. If the culprit is the power line adapters, would adding the fiber media converters after the powerline adapters and before my Zen server potentially eliminate or reduce audible noise?

Never mind. Pretty sure that won’t work. I’ve already tried a GigaFOIL v4 which didn’t help the issue.

Hi @tholt,

Getting the powerline adapters out of the way is a good step, you may also want to try a different USB cable for your DAC connection and try plugging the DAC itself into a grounded power strip.

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Hi @noris Noris, thanks for the tips. Once I get the long ethernet cable to test bypassing the adapters, I’ll know more on that front. I use a Curious USB cable so I’ll assume that’s sufficient. The DAC is plugged into a grounded power strip (Shunyata).

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No, i had no real objective reason to go with the ubiquiti. It was a matter of trust in the brand, and a matter of mistrust of most other solutions available over here (Netherlands). Already had some very good experiences with some of their NON mesh solutions, which were top of the line.

Hi @tholt !

Is there any progress you can report ? Did you test with an ethernet wire already ?

Let “us” know if we can provide any further help. Leaving an answer or solution, is helpful for this community as a whole :wink: .

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Considering you’re having the same problem with two different Core machines, both connected via USB to your DAC, I’d say these issues don’t have anything to do with the network. Instead, you may have a bad DAC. A decently engineered DAC should filter out any extraneous electrical signals, which would be what’s causing the noise. Or it could be broken. What kind of DAC is it?

Another possibility is the power to the Core machine and/or the DAC and/or the amp.

Are you using bandwidth-heavy signals? High sample rate, or DSD, or some such?

@Marco_de_Jonge thanks for the follow up. I’ve had the long CAT cable for almost a week now and in all honesty, what has stopped me from trying it is that due to the shelf and how my system is placed in it, it is physically an absolute PITA to un/replug the ethernet cable into the back of my server. But I’ve now done the experiment and here’s what I;ve found:

  • There is still noise using direct connection from modem/router to the server. Albeit, the noise seems to be less. However, most importantly, I still hear noise. So evidently it’s not the powerline adapters wholly at fault.

  • @Bill_Janssen, unplugging the USB cable from the back of the DAC has no effect on the audible noise, so it’s not USB related. Also, no bandwidth or processor heavy things. No DSD, no DSP, usually just streaming Tidal.

  • Reconnecting the powerline adapter ethernet cable to the server, the noise seems to intensify. So it appears that I’m dealing with a compounding situation?

  • Disconnecting the interconnects from DAC to amp significantly lessens the noise, but it’s still faintly audible. But this in itself is interesting because I can still hear the noise in both channels despite the interconnects being unplugged.

  • Finally, turning the volume pot on the amp affects the noise. At 0 there is a lot of noise. Turning it up, the noise lessens. This is repeatable every time.

Thus, it would appear now that it has something to do with the amp, and/or it’s volume pot? Again, it doesn’t sound like a ground loop or hum, it’s a scratchy sound that directly correlates with any Roon interaction. If I play a track, or move screen to screen etc, the noise instantly intensifies with those actions. This is why I thought it was my previous mac mini. It definitely has something to do with interacting with Roon, but I’m at a loss as to what the connection is.

One more thing – the amp is the newest member of the family. Now that @Bill_Janssen suggested the DAC, I got to thinking if I had ever heard the noise before with other amps connected to the DAC. The answer is no. So presumably, it has something to do with this amp. FYI, the amp is a tubed amp, if those are more prone to electrical noise? I mention this because whenever I turn the amp off, I can hear a rush where the noise intensifies and then slowly fades away with the amp powering down. Also, I’ve tried changing tubes, and doing so can affect the level of noise, IOW different tubes can decrease or intensify the noise.

Hi @tholt,

This does sound like it could be due to the DAC itself, it might be worth reaching out to the manufacturer.

Also, I was scanning this thread again and I don’t see you mention the model/manufacturer of the DAC/Amp anywhere (unless I missed it).

Hi @noris , curious what would draw you to that conclusion? It’s a Aqua La Voce S2.

The amp is an older ampsandsound amp called SE-84. 2x EL-84 power tubes, 1x 12AU/T/Z-7

When you removed the powerline adaptor did you remove it completely from the mains, do you have others around the house? When I used them I found they interfered with my phono preamp as it was very sensitive and I had to remove all of them on my network. The higher bandwidth ones where the worst culprits to, the lower av500 not so much but you could heart the noise floor raise with them in. I replaced them all with hardwire and a decent wireless system, they really are horrible things and can lead to network issues as they are not true ethernet devices. I would recommend using a decent wireless system over powerline any day of the week.

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Hi @tholt,

You mentioned this:

So even if there is nothing connected to the DAC except the power cable, you’re still hearing the noise through the Amp correct? And if the DAC and the Amp are not connected to each other, is the noise still present through the Amp? If so, this sounds like it could be a dodgy power supply on the amp.

Hi @noris,

Yes, I unplugged the RCAs connecting DAC to amp and I still heard a faint sound, so it seems like it may have something to do with the amp. As I also mentioned, different tubes can make the noise more and other tubes make the noise less (the tubes themselves are not noisy, they are just affecting the electrical noise that I hear). So I do wonder if it’s the amp.

Perhaps it’s a compound issue, where there is noise on the circuit and the amp is simply exacerbating it? Or would it solely be the amp?

At any rate, I might be shopping for a different amp for other reasons and also hope that a different amp will also mitigate the noise issue.

Isn’t that why they put tubes in an amp? :slight_smile:

Seriously, it sounds like the amp. Can you borrow one from a friend and swap it in to test?