2. analog
  3. 127317-5312

Periodic noise

My system picks up noise every eight minutes. There is a kind of scratching mid-register ("ta-ra-ta-ta") sound that last for ten or fifteen seconds. It is similar to descriptions of "GSM buzz" but it happens regularly and regardless of whether our mobile phones are on or off. It happens when the analog source is selected, not other sources (or not obvious, in my system). It is very clear when the volume is mid-high, with no music playing. It is not from the cartridge and the tonearm cable, since it happens even when I disconnect them from the phono stage. When I disconnect the phono stage, however, I don't hear it. So it seems to be picked up from the phono stage itself. It happens across different phono stages. Shielding the cables with ferrite does not help much. It seems like a very strong signal.

Anyone recognizes this problem?
o_holter

Showing 2 responses by dbtom2

dbtom2
295 posts
 
Every eight minutes? And lasts for ten or fifteen seconds?

If you live in an urban setting or an apartment, discovering the source of this may be more difficult. 

Look at any other wireless devices used around the house. In particular, those that may be close or too close to the hifi. A Wifi router could be one culprit. Another could be a device like a weather station remote or monitoring system that periodically connects to your network. (Or is your neighbors, looking to connect on your neighbors network.) Some GPS devices will have an interval like that to upload a changing position. Others, like those flat, white, locator tabs that help us find lost keys. Camera monitors, refrigerators, light switches, hot water heaters. 

So much of life today is connected wireless. Do you have one of those new thermostats?

These things aren't supposed to interfere but many do. Sometimes the interfering noise may be a sign that the equipment may be starting to fail. Other devices are just plain nasty. I had a Sprint Blackberry model a few years ago that disrupted everything right before it rang. 

Good luck.

dbtom2
295 posts
 
@almarg @o_holter 

The OP didn't say how long the interfering device had been in place or how long the interference (noise) had been perceptible. 

So my question is: Could this noise be "a canary in a coal mine?"

In other words, if the devices had been in place for awhile but the noise only recently began to be heard, would it be an indication of something failing (a noise shunting capacitor perhaps?) in the signal chain?

Not that I want to turn over too many rocks but I am curious....
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