24 Jan
2010
24 Jan
'10
4:51 p.m.
Arnold Krille wrote:
On Sunday 24 January 2010 18:26:13 Martin Peach
wrote:
Well it depends. High frequency noise is usually filtered using
small-valued caps because electrolytics are just no good at high
frequencies. But yes, there should be no AC hum from a PC PSU, just a
mess of high-frequency spikes. But it should have _some_ harmonic
content, not just white noise. Usually sounds like a noisy whine.
Martin
So I took the card out and now it's running
in a WinXP box with no
issues. So it's definitely not the capacitors. I think the sound of dead
capacitors would be more like AC hum.
Dead capacitors are not causing AC hum, they are causing high-frequency hiss
because the high frequencies of the switching powersupply in your machine
isn't filtered any more. (One of the problems I am facing here with my diy amp
using an old PC PSU while trying to not use capacitors for filtering.)