[SOLVED] HP Compaq NX7400

[agent_kith]

Thank you very much for everything.

It's my pleasure.

You can try swap out the computer SMPS to a ultra linear PS, e.g. JS-2.

Also, because the computer (bus, CPU, etc) are running at a highish frequency, it's also a good idea to put the computer in a metal computer case (or a plastic case with some grounded sheild lining). That way you can reduce any potential environmental noise. However, for reasons I can't fathom, this can "dull" the sound. So at the end of the day you may actually prefer the sound from an exposed layout. At least you have tried both approaches and pick the one that fits you best.