2. amps-preamps
  3. 183915-158670

Help with hiss

Hello Friends,

My speakers have developed an audible hiss that I am trying to chase down. The hiss can be heard from across the room and while music is being played. Sometimes, the hiss is pulsating and sometimes constant. It occurs at all hours, perhaps less so in the early morning. Sometimes there is no hiss at all and everything is silent. It is an intermittent issue that is unpredictable.

My speakers are powered by mono block amplifiers. Both speakers exhibit the exact same behavior. The monos are plugged directly into the wall outlet. I also plugged them into a PS Audio AV Power Center with no relief. I changed power cords with no relief. No other piece of gear is on, although all are plugged in and some are in standby. I turned one mono off of course stopping the hiss in that speaker. The other continued to hiss. In reverse, same result.

This is not a “hum” (like from a ground loop). It is the same hiss that you can hear with your ear next to the tweeter but much louder.

I’m happy to answer any questions at all to help me resolve this. Thank you in advance.

 

forestg
forestg OP
26 posts
 

@soix Thank you so much. This is definitely a drag. It does happen at night, but my listening may start before the hiss starts. Once the hiss starts, it’s pretty obvious. Even my wife noticed it. I had feared that it might be something in the grid. My neighbor had recently built a wood shop. When I heard the hiss, I asked him if he was using any of his shop tools (sometimes the hiss sounds like a saw starting up). He denied using anything in the shop. It also occurs when he’s not even home.

@ditusa  Since you ask, I’ll assume it matters….Odyssey Audio Kismet Reference monos and Odyssey Audio Kismet monitors. Flawless performance for years. Thank you!

nd1der's avatar
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nd1der
43 posts
 

You said that your amps are plugged directly into the wall outlet.  What else is on that circuit? Have you tried unplugging everything else that's on that circuit.

I installed two dedicated circuits for my gear. One is used for the power amps and the other for the rest of the gear. Noise was reduced to virtually zero.

Good luck.

forestg OP
26 posts
 

@carlsbad2  I had given that some thought, and I agree that it is likely upstream from the amps/speakers. Question: my preamp is a tube pre that is not on or in standby mode. It is plugged in, but fully “off”. Could it still create a problem? Thank you!

forestg OP
26 posts
 

@nd1der  All the rest of my gear is plugged in to a Brick Wall, which is plugged into the same circuit. This includes the Mac laptop that I use for steaming. Knowing that computers can cause issues, I unplugged that from the Brick Wall with no relief. I’m not sure if it’s on the same circuit, but my internet modem is in the same room. Concern that might be an issue, I turned off and unplugged the modem with no relief. Thank you! Keep it coming!!

erik_squires
16,037 posts
 

So, for the LED thing, dimmable LED lightbulbs seem to be OK but some LED strips and power supplies are not. If your LED lights have a wall wart, that may very well be a cause.

Another potential issue is if you've moved or introduced a Wifi router or device around your stereo recently. 

One experiment you might find is to literally turn off everything else in the house from the panel. 

If turning all of that off does not improve your issue then it's definitely in your audio chain.

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