power from the wall seems to be 'dirty' at night

Techno Pride · Post by **Techno Pride** » Wed May 30, 2007 8:02 pm

hi all

i've this problem with my computer that seems to surface only at night. The audio crackles and pops. I'm guessing it's because there're more people home at night, thus the usage of more electrical devices in the house.

In the day, sound is silky smooth and perfect. I have this problem with both an FSP Bluestorm 350w and Antec Earthwatts 430w PSU. The wiring in my house is nearly 20 yrs old.

Would buying an UPS help somewhat?

thanks

rig as follows

AMD X2-3600, Abit NF-M2 nview
2gb Kingston DDR2-667
Asus 8500gt
Samsung SP1614N, Seagate Barracuda 4 80gb
SB Audigy, Creative Fourpointsurround FPS2000
Antec EA430

Mr Evil · Post by **Mr Evil** » Thu May 31, 2007 6:57 am

You might try a power strip with filters built in. I think it's unlikely that the noise is coming from the mains though, since the PSU should do a pretty good job of keeping that out.

Where I live the mains are very clean, but there is a huge amount of radiated noise at certain times of day. Keeping that out is hard; shielding the electronics, using good quality coaxial cables for the audio signals and re-routing them away from other cables all helps a little.

Also, if you're taking the audio from the front panel connectors on your case, try using the ones on the back instead, since a lot of noise can be picked up on the journey past all that digital circuitry. It's probably not that though, since that would be constant at all times of day.

jaganath · Post by **jaganath** » Thu May 31, 2007 9:39 am

Where I live the mains are very clean, but there is a huge amount of radiated noise at certain times of day.

out of interest,where is that radiated noise coming from? traffic?

Mr Evil · Post by **Mr Evil** » Thu May 31, 2007 9:50 am

jaganath wrote:out of interest,where is that radiated noise coming from? traffic?

I have no idea. There's a big peak at 50Hz, which must be from mains powered equipment, a couple of peaks at 10-20kHz from somewhere, and then a bunch of RF, maybe from things like mobile phones perhaps? I hadn't thought about traffic... I'll look into it when I have the opportunity.

fri2219 · Post by **fri2219** » Thu May 31, 2007 10:29 am

I used to work with high-resolution NMR for deciphering what molecules looked like. One of the technical issues with spectroscopy is outside interference, including line noise. We had a particularily bad stretch for a while, until we discovered the source of the noise was a construction project three blocks away.

The point I'm trying to make is that your problem is probably well outside of your control. You might be able to fix it with a line conditioner. If you're serious about power quality, avoid consumer level devices that are just UPS's or surge supressors.

Point solution line conditioners aren't usually very cost effective. A decent ART, ETA, Furman, or Panamax conditioner will probably cost as much as a whole house device- they're mostly aimed at sound professionals recording on-location and home theater lunatics who sink 80K into their setups.