I got some really good suggestions here last year regardning an USB-humming noise, and now some year later, I might try this forum again.
After being away for a week, returning home, switchin on my amp, suddenly I hear a constant "puff" from the left channel (speaker).
It sounds like the noise you hear when switch off some systems, like a condensator is being decharged. Very weak noise but indeed noticable.
The Hz is about 30, so every 2 seconds the "puff" will sound, it is a short sound, like 1/10 of a second.
0s-[Puff]----------------------------------1s----------------------------------2s-[Puff]---------------------------------
It doenst matter which input I choose, only disconnected ones are silent. And the amp even makes this noise while being only thing with power. My PC is connected via OPT-1 and USB. When turned off (PC) no puffing sound, but as soon as the Rotel gets a signals, the amp makes the "click" and start to amp, and then the puff starts.
That is when I found the cause. And it made me a bit electric.
The SUB-woofer line out is connected to a amped subwoofer (powered by an other outlet) and when I unplugged the line-cable two things happened; 1: I got somewhat electified, I could feel the voltage running thru my arm and maybe leg, and 2: the puffing noise stopped!
And that concludes the topic: my apartment lacks some kind of good power lining and I have to think of something smart to fix this.
Any suggestions is nice, but think of this as a log so someone else might get help from it.
Good long summer to you all!
After being away for a week, returning home, switchin on my amp, suddenly I hear a constant "puff" from the left channel (speaker).
It sounds like the noise you hear when switch off some systems, like a condensator is being decharged. Very weak noise but indeed noticable.
The Hz is about 30, so every 2 seconds the "puff" will sound, it is a short sound, like 1/10 of a second.
0s-[Puff]----------------------------------1s----------------------------------2s-[Puff]---------------------------------
It doenst matter which input I choose, only disconnected ones are silent. And the amp even makes this noise while being only thing with power. My PC is connected via OPT-1 and USB. When turned off (PC) no puffing sound, but as soon as the Rotel gets a signals, the amp makes the "click" and start to amp, and then the puff starts.
That is when I found the cause. And it made me a bit electric.
The SUB-woofer line out is connected to a amped subwoofer (powered by an other outlet) and when I unplugged the line-cable two things happened; 1: I got somewhat electified, I could feel the voltage running thru my arm and maybe leg, and 2: the puffing noise stopped!
And that concludes the topic: my apartment lacks some kind of good power lining and I have to think of something smart to fix this.
Any suggestions is nice, but think of this as a log so someone else might get help from it.
Good long summer to you all!
