Pulsing hum

David Cole · Post by **David Cole** » Mon Mar 13, 2006 2:39 am

My newly built system is Seasonic S12 430w, AMD Athlon x2 4400, Asus A8NSLI-Premium, ThermalRight SI-120, Nexus 120mm, Gigabyte passively cooled 128Mb vga card, x2 Samsung 200Gb SWP20149 hdds. I am experiencing a wavering, or pulsing hum. At frist I thought this was from the hdds but on closer listening it doesn't appear to be them - they are suspended in cradles and do not seem to hum. I think it is the S12 psu - when the S12 powers down, there is an audible noise like a descending note and the hum disappears. I have tried an S12 500W and that too has a wavering hum, and also a new Zalman ZM460-APS which has no hum but is quite a lot noiser than the Seasonics.

Has anyone else noticed this humming from the S12? I am a bit flummoxed as to what to do next. Grateful for any ideas. Thanks.

David

Dru · Post by **Dru** » Tue Mar 14, 2006 10:30 am

That's funny. I've noticed this with my stock PS in my Antec SLK1650B. When on, has this oscillating whine which has a recurring time of maybe 15 seconds? It will go up... then down and repeat.

Ironically, I am going to replace it with an S12.

David Cole · Post by **David Cole** » Wed Mar 15, 2006 11:53 am

Mmm. My hum is not really a whine. It's a hum which slowly goes up in pitch and then back to the starting pitch, then slowly up again etc. I am pretty sure it's the S12 because the hum stops when the S12 powers down (with a whine). I am willing to change the psu but to what? I have tried the S12 500w but this is noisier and hums, and the Zalman 460w which is just noisier. I was wondering about the Nexus NX5000 - I had a good experience with the Nexus 3500. Any thoughts?
Good luck with the S12.

David

Dru · Post by **Dru** » Wed Mar 15, 2006 12:45 pm

I just purchased 2 of the S12 380W ones. I should be receiving them tomorrow 3/16/2006. I should have an assessment by Friday.

I hate how it's hard to describe sound on the internet. I shouldn't have said whine. I really don't know how to describe it. It just gives off some frequency like the old CRT TVs or something. It does the slow oscillating change in pitch over time.

Another thing to note is that power supplies might give sound based on their current load? One thing to try would be to disconnect some devices and turn on the computer (like the optical drive and possibly a hard drive) to see if it emits the same sound.