Help with hiss

@soix Thank you. Excellent question and something I forgot to include.

I’ve owned this system in its current iteration for a few years now. This hiss started maybe 2 or 3 months ago, but I lose track. The only new “thing” I’ve added to my home is a conversion of a kitchen ceiling light from fluorescent tubes to LED. Fearing this may have cause it, I turned the light off but the hiss continued. It also does it in the bright of day when no lights are on. I’ve also studied if the hiss appears when the refrigerator cycles on. It does not coincide, and again, I’ve had all the same stuff for years.

Damn!  Does it still occur with listening at night?  Maybe it’s possible something outside your house but in your electrical grid has changed.  If it was me I’d try a balanced power conditioner (like Underwood Core Power or Equi=tech) or a power regenerator from PS Audio.  Other than that I got nuthin, but you’ve got my sincere sympathy and hope someone smarter than me here can help you figure it out. 

@forestg,

What mono block amplifiers and speakers do you have?

Mike

Assuming the hiss comes from both speakers, then it is not your speakers or your amplifiers.  It comes from further upstream, a component that processes both channels. 

I would guess your preamp.  

@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!