Onboard Audio Chip Noise (cannot figure out) - diyAudio
Go Back   Home > Forums > Source & Line > PC Based

PC Based Computer music servers, crossovers, and equalization

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 20th September 2014, 03:39 AM   #1
diyAudio Member
Join Date: Dec 2005
Question Onboard Audio Chip Noise (cannot figure out)

I have a Supermicro C2SEA board which sports the Realtek ALC888 (HD 7.1 channel audio).

I keep getting a computer-sounding background noise (quite lowlevel in audibility but is easily faintly noticed during pauses in sound). It sometimes happens when I move the mouse around the screen. And, it sometimes happens when the HD drive is accessing data and when the network chip (on the motherboard also) is transceiving via CAT6 a large amount of data.

Could this be an issue with an improper ground? Or, could this be an issue with the PC's power supply? Supermicro does not make bad boards.

I do know that lowlevel noise can happen in automobiles, why, and how to fix it. But, never had this before in a computer.

And, this has been the case for years (the board is from 2007 I believe). I have been using an E-MU 1820m system or ESI Waveterminal 192X card to get around the problem.

For testing, it would be cool if someone could tell me how to "shield" the PSU from the motherboard or make a tiny shield around the Realtek chip to temporarily see if that helped (Faraday cage, right?).

  Reply With Quote
Old 20th September 2014, 03:49 AM   #2
diyAudio Member
abraxalito's Avatar
Join Date: Sep 2007
Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Blog Entries: 103
Send a message via MSN to abraxalito Send a message via Yahoo to abraxalito Send a message via Skype™ to abraxalito
I don't believe its feasible that shielding will do any good because this problem is unlikely to be due to radiated noise. There are probably a couple of issues here - common mode noise and common ground impedance coupling. Both of which are caused by interference currents flowing in ground conductors. If you could get a ground connection (for the audio output) right on the ALC888 IC you might fix up the second of these issues. The first is tougher to solve - going to a linear PSU for the computer will most likely help.
No matter if we meanwhile surrender every value for which we stand, we must strive to cajole the majority into imagining itself on our side - Everett Dean Martin
  Reply With Quote
Old 20th September 2014, 05:27 AM   #3
sangram is offline sangram  India
diyAudio Member
Join Date: Sep 2002
Location: India
This is not a problem that can be actually resolved. The only way to see of the board is the culprit or not is to replace the power supply.

The last time I encountered this issue, even that did not helps as the board's onboard filtering was inducing a massive amount of junk into the PCI slot power inlets and the power line for the onboard audio. Only replacing the board solved the issue,

It's not a question of supermicro making bad boards. It's just not intended to be used for any serious audio work, just system sounds. You're art least lucky that the pci slots are getting decent power.
  Reply With Quote
Old 20th September 2014, 05:27 AM   #4
diyAudio Member
Join Date: Dec 2005
Thank you. I will investigate and make attempts. The ALC888 should be a pretty decent chip although I like my E-MU 1820m and WaveTerminal 192X better, heh.
  Reply With Quote
Old 23rd September 2014, 02:17 PM   #5
marce is online now marce  United Kingdom
diyAudio Member
Join Date: Jun 2007
Location: Blackburn, Lancs
simultaneous switching noise is also a culprit.....
  Reply With Quote


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Flicker Noise dominates triode noise in audio (AES) ruffrecords Tubes / Valves 67 25th April 2014 06:35 AM
Noise detection chip? plasmaninjaa Solid State 3 16th January 2013 02:58 PM
Low noise transistor and noise figure Real_Macgyver Solid State 28 27th July 2012 09:42 AM
Noise figure vs signal source resistances in JFETS datasheet rlim Solid State 25 19th December 2003 07:11 PM
Trying to figure out how to get rid of noise, help is welcome! Jean Solid State 41 26th June 2003 04:02 AM

New To Site? Need Help?

All times are GMT. The time now is 02:28 PM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2