Internet Noise: A Pest in the Machine

You need to rule out what it isn't first. Try playing stuff with no internet, just a CDP and see if it recurs.

I agree. That has been my approach. I have used my phono stage and have been able to play records with no issue. I do not have a CD player but could borrow one as an experiment. It seems pretty clear that the noise is related to the internet, since I do not have any when it is disconnected. Other than that, I am in the weeds.

I had a power line adapter interfere like that.  The digital was riding on the phono pre out as seen on an o-scope.  Any in the house?

So it's worth investigating the power output of your wifi router.  Since moving it helped some.  Most routers have this setting buried in the user interface (UI). If your home is small, and you don't need very wide coverage this may help.  It's also more secure as it is less likely a hacker will drive by and see it. 

Try turning off the wireless 2.4 and 5GHz if it is enabled in your router.  If that solves the interference, you could manually select different wireless channels in the wireless settings of your router and see if that helps.

TP-Link is pretty cheap stuff.  You could try a better quality router from a store with a good return policy.  The router could be giving off 

Thanks, all. I will follow up on these suggestions and do some investigating.

A while back I had a similar problem, and it was finally resolved when I noticed the ground inside the cable entrance enclosure on the side of my house…  was disconnected.  I connected it securely and my issue went away.  Might not be your issue, but worth checking. 

I have a similar issue. Static noise in the system, and with 106dB sensitive horn speakers let me tell you it is sometimes unbearable. It comes and goes, sometimes it is juts faint, sometimes it's unbearable.

I want to try a couple Ifi Audio AC iPurifiers, see if it does anything, then I will know it comes through AC. If it doesn't help, then I will know it enters from another point in the system.

But yeah, my house is full with devices that have the ability to produce nasty pollution: Internet router with a second remote router for the wi-fi to reach the rest of the house, smart lamps that are remote controllable from my phone, and then the upstairs neighbors are an office full with computers and a big server. there's no way I can isolate or turn them off, so I will try to stop it from getting inside the system. Easier said than done!

Thanks for the continued feedback and shared experiences. Just for some added context, I have not had these noise issues with other amps, especially solid state amps. It is not that I think the Synthesis is to blame, not at all. But the tubes appear to be picking up this pollution and it is almost surely related to the internet, since when I disconnect it or unplug it, the noise vanishes.

I will be experimenting more in the days to come and following up on some of the suggestions made so far.

@rolox 

I feel your pain. It has taken me a couple of months to trace the problem down to the relationship between the internet and the amp. I initially thought it had to be faulty tubes or a something going on with the amp, but after much trial and error, it seems the issue is figuring out how to tame the internet noise.

Hello! 

I used to work for the importer- in fact I believe we spoke when you first got the amp about how it is biased- though I could be wrong on that. Either way unfortunately not the first person to have issues with tubes picking up wifi noise. Definitely not just a Synthesis thing, Ive seen it happen on a variety of different brand products.  

The first thing to do is always try moving the router if you can, since you already did that the signal must be coming from the switch. A good way to check this, if possible, is to move the switch around the amp and see if there is any change in the noise from the amp. Sometimes you get lucky and it can be as simple as turning the switch 90 degrees and suddenly its dead quiet- Ive driven an hour each way out to customers houses and fixed it just like that. 

If you move it around and the noise gets louder/quieter then you know its the switch causing the issue. If the noise doesn't change at all then it has to be a different switch or something else. 

If it is a switch then there are a couple different solutions you could try:

a: You can move the internet equipment out of the room or farther away and just run a long ethernet cable to you streamer.

b: You can try a different switch, I wouldn't say it needs to be a fancy audiophile switch necessarily just something that is shielded better than it sounds like your current one is. 

c: You can also try replacing the input tubes on the amplifier, the small 12AX7 tubes, as sometimes- rarely- certain small signal tubes happen to be more susceptible to RF noise than others. If you went that route I would recommend trying a different brand of tube than whatever stock is as they often have different construction internally. 

Hope this is helpful! 

@steakster 

+1. I made the mistake of having a friend buy a TP-Link router… it was faulty. I have had several Nighthawks now… they work great for a couple years, easy to install and add on extenders for streamers. 

Get rid of the wi-fi period and go fiber. 

Fiber is not an option where I live unfortunately.

I will try a better switch tomorrow and see if that helps, perhaps a Nighthawk. I appreciate all of the suggestions.

@waltersalas In my case, I used a "ground lifter" on the incoming coax.  Can't say I noticed a change but I had no issues.  

https://www.amazon.com/dp/B08FRGH4X2?psc=1&ref_=cm_sw_r_cp_ud_ct_2Z5MM0TACZ9T4KCQ3QHK

I would buy a cheap wall wart extender and plug your Aurender into that. This will isolate you from the router. This is how my systems work, from extenders.

If that doesn’t work. Swap out all the tubes… you should have a spare set anyway. If it goes away, then you can slowly swap back one tube at a time until you find the offending tube.

I tried a different switch today. Did not solve the problem. Next will be moving the cables and switches into the next room with the router, and then running a long ethernet cable back into the room and into the Aurender. If that doesn't do it, I will try some tube swapping.

It's almost enough to make me go back to solid state. Almost.

I doubt this will be your answer but I was dealing with some noise issues that seemed to be related to my cheap switch. Some of this was mitigated by wrapping my switch with the following tape:

Faraday Fabric Tape 2inch x 50... https://www.amazon.com/dp/B097HC9HR7?ref=ppx_pop_mob_ap_share

There was mention of going fiber which would replace your long Ethernet cable run when you put your router and modem in a different room. I had a lot of questions about implementing fiber into a system to reduce noise myself. The first three post to the thread I started are relatively cheap, but it would essentially look something like this:

Modem > Router > Switch > Ethernet > Fiber Media Converter (FMC) > fiber (long run) > FMC > Ethernet (very small run) > Streamer

https://forum.audiogon.com/discussions/network-acoustics-eno-streaming-system-vs-sgc-optical-isolation-system

Worth a try. I’d be pretty frustrated if I were in your shoes. I’m sure you’ll figure it out.

Sounds like a problem with your cable coming into the house with either a bad cable, connector and/or grounding of system to earth ground. Call your cable company and they can test for good signal to noise ratio and power levels as well as inspecting and/or replacing bad wires or connectors.

Other suggestions:

Do you have dedicated AC power circuits for your equipment? If not, have 2x20 Amp dedicated lines installed. Put analog equipment on one circut and the digital equipment on the other. Replace Ethernet cable with a tested Cat 6 (not Cat 8) cable from vendor such as Blue Jeans Cables on Amazon. You can also try a Furman PST-8D power conditioner. Replacing router and switch with a metal case are also good recommendations although it is not necessary to use a so-called audiophile switch. Routers and Ethernet cables provided by your cable company are often cheap and of low quality so consider replacing them if no issue is found with your incoming cabling. Fiber Ethernet is your best bet for noise isolation so consider it as well as it is easy to hook up and inexpensive. Good Luck!

Thanks for the help, folks. You have no idea how much I appreciate it. The cable coming into the house does seem to be pretty shabbily terminated.. There is some exposed wire and the cable can be twisted into an L at the switch, if that makes sense. I am keeping a good thought that maybe this is the issue.

I have contacted the cable company for more information and asked these questions.

I am certainly open to the fiber optic and converter option. I bought a Netgear switch that is certainly sturdier than the cheap, plastic TP-Link switch, though the Netgear is also pretty basic.

You folks have given me a lot of great ideas to explore. Thank you kindly!

By the way, I do have a dedicated circuit, and a Puritan 156 power conditioner. I have my components plugged into that, but not the ethernet switch. That might be worth a try.

Have you checked the tubes yet?

I have checked the smaller tubes, but I do not have a substitute KT66 tube to try yet. The amp is new, so the tubes have maybe a hundred hours or so on them. One complication is the KT66 tubes are manual bias, and the design makes is very difficult for the user to do it--difficult and perhaps a little dangerous, which makes swapping out the power tubes somewhat problematic.

Most Digital devices emit rf noise that must be managed somehow.

Keep all digital devices as far away from integrated amps or pre-amps as possible. Unless specifically designed otherwise to effectively address noise issues.

Most truly good quality hifi digital devices these days are pretty well designed to address noise issues but most commercial or other consumer digital gear is not

Whenever in doubt, isolation, both physical and electrical, are your friend.

FWIW I have an all in one Cambridge Evo that has everything including phono built in and the thing is always dead quiet.  Very impressive!

For whatever it may be worth to anyone who contributed to this thread or may stumble upon it in the future--especially for anyone who may have a Synthesis amp or be considering one--I seem to have found a solution to the noise problem.

It turns out that the amp did not like being near ANY of the internet gear--router, cables, switches, power supply, none of it. I moved all of it to another room and now have only a single ethernet cable remaining in the music room, which of course is connected to the streamer.

I would have tried this sooner, but with the exception of one person, no one I talked to on either side (amp dealer or importer) or my ISP thought there was much of a chance this was the issue once the router was taken out of the room, which did not solve the problem. 

Prior to moving everything, I tried a new switch, but that also did nothing. For whatever reason, moving all of it was the answer. I will wait at least a couple of weeks before declaring victory, but this is a tremendous relief to say the least!

Yay!  Glad to hear it’s better now. 

Thanks so much, guys.. This had become the ultimate conundrum--best amp I've owned, but an annoying problem that was robbing me of enjoying it. Now that the noise issue is gone, I can very highly recommend Synthesis amps to anyone without any reservation. 

OP,

Thank you for the follow up on how you solved the problem.

However, what you did to solve the problem makes me wonder. You did not change out the KT88 tubes yet, correct? Makes me wonder if it was a tube acting as a receiver. I would find it nearly inconceivable that a production model amp would be that sensitive to nearby noise. That makes the amp a really good antenna, suggesting it would pick up other nearby devices.

Anyway, if you are inclined, it would be interesting to know if the unit is still sensitive after a tube change.

The Synthesis uses KT66 tubes, and I do not doubt that the amp was acting as an antenna. If the noise problem recurs now that the system is quiet as a church mouse, I will try tube swapping next. I once had a tube amp that picked up conversations my neighbor was having on his ham radio.

For now, after weeks of tedious trial and error and considerable frustration, I will be enjoying the music for a while. :)