Help with hiss

@forestg just wanted to chime in when I saw your post.  I noticed the same "hiss' coming from my Rega Elex~R integrated.  I thought it was for certain my tube dac, but after disconnecting everything, moving the amp, and trying different speakers I can still hear a hiss but at normal mild listenting levels it's inaudible; you can only hear it at that level if you happen to be right next to the speaker.  If I crank it, then you can hear it from across the room, especially if you listen for it.
Fully agree with others on checking the bias. 
Hope it's nothing harmful and you figure it out.

@tee_dee I may have to spend the rest of my life figuring this out! It can’t stay like this!

@wturkey Thanks! I may have one left over when I had to chase a ground loop hum in my (home theater) subwoofer.

@panzrwagn Thank you so much for this! Very informative. I’ll read those articles if for no other reason than to learn more about our crazy hobby! I can’t rule this out, either. These amps have pretty high input sensitivity and, I believe, are a high gain design.

@perkri I did not disconnect the RCA’s from the amp..from either end. I did swap out power cables and I did plug them in directly to the wall outlet and into a PS Audio Power Center. Nothing changed in any scenario. Unplugging the inputs at the amp is what I will try next, based on a previous recommendation 🙏🏻. The hiss stays constant. No change with volume adjustment, nor input selection on the preamp. It does it with nothing but the amps turned on. Thank you!

@rbull11 Great thought! Alas, everyone hears it. It is real. But I, too, suffer from Tinitus and have often made sure it was the speakers hissing and not my head! Thanks!

@amtprod I’m definitely going to look into the issue of bias. I hear a lot about it, so it clearly has great impact. This is a “on or off” kind of hiss. It’s either doing it or not. And it does not change with volume or input changes at the preamp. And you can hear it quite noticeably “under” the music when it’s playing. Like a lot of background noise. Quiet passages aren’t quiet. It’s very annoying not to have the clarity I’m used to. These are pretty “crisp” speakers (Scanspeak beryllium tweeters). Thanks!

@serjio I will have to look in to that. Sounds intense. I was concerned that something else from someone else was shitting into my system, but hey, you never know! Thanks!

I have an Odyssey Audio Stratos. For 20 yrs it was dead quiet. In 2021, I sent it to Odyssey for a Kismit upgrade. It came back with a hiss in the speakers and transformer hum. I sent it back (almost $300 in shipping by now). They said that they replaced everything. When it came back, it still had hum and hiss problems albeit at a lower volume but hiss nonetheless. I gave up on it an bought new amps from a different manufacturer and I’m hum and hiss free again. Now the Odyssey just sits on the floor at the back of my room…just sitting there…mocking me every time I walk by :_

BTW, it always had bias issues. It was always a crap shoot as which side the center image would be leaning.

Here’s another thing to try. 
 

when amp in, connected to speakers with nothing else connected, try holing into the rca connectors and see if the noise subsides 

other thing to check, is the DC on the speaker outputs if you have a multi meter.