Noise in Headphone amp

[Music Manic]

When I boot the computer and DAW software programs I get quite a lot of noise plus a slight whine.
You can't really hear it at low gain but when I turn the gain upto full on my headphone
amp you can hear it clearly.

The noise sounds like analogue and is quite natural but the whine only appears when I load my DAW. Now that's weird. Any ideas guys?

Thanks

[astroman]

groundloooooop

there's some connection somewhere, often totally unnoticed... in my case I remember the S/PDIF cable of a digital recorder that served as a converter for another PC.
Analog output of the recorder went to the main preamp, which had some inputs fed by the Scope system ... and voila zzzzssszz
Nothing beats a good transformer AND a great analog powersupply - totally in love with my Telefunken N324

cheers, Tom

[Music Manic]

Thanks Astroman.

I'm also getting zipper noise when I move the graphics windows.

There are things sharing IRQ on ACPI which I can't disable. Are these the problems?

Thanks

[astroman]

iirc the 'noise effect' is emphasized by IRQs (or IRQ problems), but that may be related to increased system load.
As 19thbear answered in your other thread, the signal is spread on ground and may also(!) fold back on analog lines.
Since I have the guitar and mic stuff transformer-balanced, I have barely no such noise at all, even with all settings fully cranked up.
The process to sort this out can become quite tedious. 19thbear described it perfectly...

cheers, Tom