[SOLVED] Hissing sound when PC speakers connected to amp.

[jurselis]

hey guys
so i have this sony amp 1970
i connected amp with speakers to pc
and i can hear hiss....
so for example:

1. it will be fine,no hiss, untill my old hdd starts spinning, in that moment, (startup/waking up from nap) hiss sound comes from speakers, after 10-20s hdd stops waking up proccess and his stops
2. if i move mouse after while, his will appear for few seconds and then goes away

and similar stuff all the time.
anybody has any idea?
i tried playing with cables (stereo would not touch power) played with power sockets (connecting everything in to one or multiple) tried disconecting all other stuff like lamp or monitor......
sorry for owfull english

 

[alceryes]

Try temporairly removing the case front panel USB and audio headers from the motherboard and use just the motherboard connectors in back. If the hiss is gone then the cause is a ground loop between audio ground and chassis ground or USB ground. A very common mistake that tower PC enclosure manufacturers make is to connect the audio ground and USB ground together at the front panel PCB.

 

[drea.drechsler]

hey guys
so i have this sony amp 1970
i connected amp with speakers to pc
and i can hear hiss....
so for example:

1. it will be fine,no hiss, untill my old hdd starts spinning, in that moment, (startup/waking up from nap) hiss sound comes from speakers, after 10-20s hdd stops waking up proccess and his stops
2. if i move mouse after while, his will appear for few seconds and then goes away

and similar stuff all the time.
anybody has any idea?
i tried playing with cables (stereo would not touch power) played with power sockets (connecting everything in to one or multiple) tried disconecting all other stuff like lamp or monitor......
sorry for owfull english

I got tired of chasing hiss/hum/low output sound problems from my system. It's not always the fault of the motherboard with low-end CODEC chips, as @alceryes notes it can be the computer case wireing.

So what I did was go get an inexpensive DAC and remove the analog audio signal completely from the high-noise computer case. I got a DAC that has both Tos-Link inputs and USB inputs. Tos-Link will require an output on the motherboard but USB digital output is a feature of Windows 10 that's always available.

Now I get low-noise floor sound output with strong volume even to high impedance headphones from cheap motherboards. Output to an amplifier is a snap too, with furnished left and right RCA jacks. And I get this on any system, no matter how bad the on-board CODEC is.