Internet Noise: A Pest in the Machine

I have already posted a glowing review of my new Synthesis A100 Titan integrated amplifier, which is my favorite of the many amplifiers I have owned over the years. I hope to keep it as the centerpiece of my system for many years to come.

With that said, I am having an issue that is not only perplexing to me, but to the importer and dealer as well. The gist of it is that I am getting intermittent noise (sort of a gauzy static sound) that seems clearly associated with my internet set-up, which consists of a basic ethernet switch and a couple of smaller switches, with an audiophile-grade ethernet cable running from the switch to my Aurender N20. Except for the ethernet cable, everything else is basic stuff our internet service provider brought for the install.

The importer suggested moving the router (it is actually an access point) into another room, suggesting that sometimes the tubes in the Synthesis will pick up noise from nearby routers, and also suggested moving the streamer as far from the amp as possible. Moving the router did seem to help some, and at times the system is blissfully quiet. But the noise always comes back, with varying degrees of volume.

I have pretty much ruled out the streamer as a potential cause by disconnecting the sources (streamer and phono stage) to see if the noise continued. And it did. But every time I disconnect or turn off the internet by unplugging it, the noise immediately goes away. I can listen to my analog rig with no noise with the internet disconnected, but not for long when my spouse or children complain about not having internet. When I turn the internet back on, the noise will usually come back within a few minutes.

It may be that the answer is investing some money in an audiophile switch—or even something better than the cheapo plastic TP-link switch I have now—but before I go down this road, I need to be relatively confident that this is the issue. I don't want to invest a lot of money and be back at square one.

Another possibility is moving the switches and cables into the next room, far away from the system, and just running a single, lengthy ethernet cable into the room to connect to the Aurender. Maybe the amp is picking up noise from the cables or switches, though that seems unlikely. On the other hand, one day when the noise was particularly bad, I went over and just tried jiggling the cable coming in from outside where it enters the house, and for some reason, that really helped. I have no idea why, or what is going on here. It is just bewildering.

If anyone has a theory or suggestion for troubleshooting this problem, I would appreciate your thoughts. The dealer has been no help at all (he also didn’t know that amp is manual bias) and the importer has offered suggestions but seems as baffled as I am as to what might be happening to cause this.

It is the strangest problem I’ve encountered in twenty-plus years in high end. I would be more than relieved to get to the bottom of it.



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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. 



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. :)