8 Replies Latest reply on Jul 5, 2011 9:42 AM by k00zmi4

    High Frequency MB Noise - USB Audio Interface Picking Up Too

    ncuster

      I built two systems at home last years using the same following components on each:

       

      - Intel BOXDG43RK LGA 775 Intel G43 HDMI Micro ATX Intel Motherboard
      - Intel Core 2 Duo E8400 Wolfdale 3.0GHz LGA 775 65W Dual-Core Processor BX80570E8400
      - Kingston 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1066 (PC3 8500) Dual Channel Kit Desktop Memory Model KVR1066D3K2/4GR
      - MASSCOOL FD08025S1M4 80mm Case Fan
      - Sony Optiarc CD/DVD Burner Beige SATA Model AD-7260S-01
      - Western Digital Caviar Blue WD2500AAJS 250GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive

       

      I'm using the on-board graphics, network, and audio (e.g. no other cards installed).  The only difference between the systems is one has a more powerful power supply, but the problem I'm experiencing is noticeable on both systems.  Running Windows XP SP 3

       

      I am wanting to use one for a digital audio workstation (DAW) and have purchased a Behringer UCA202 USB Audio interface to plug in my mixing board to for this purpose.  The problem is I'm getting a very high-frequency humming through the "monitor" port on the Audio Interface.  (I have very sensitive hearing and can actually hear this "hum" just by putting my ear to the back of the case/motherboard.)  I have tried everything I can think of to get rid of this noise, but most improvements are minimal.  I finally decided the Behringer interface must be bad, but I tried it on two other systems at work (a notebook PC and a desktop PC) and the background is totally silent.  Therefore, there must be something in the chipset / processor / memory / power supply configuration that is causing this high-frequency oscillating sound.

       

      I would greatly appreciate any ideas...

       

      Thanx

        • 1. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
          Flying_Kiwi

          It sounds from your description as if it may be similar to the component noise some DG45IDs made long ago (a BIOS update has been released which supposedly addresses it but that didn't do the trick on mine, I had to RMA it). Does your board have it's latest BIOS version installed? Is the noise there all the time or does it come and go depending on whether the PC is busy or idle? Does (just for testing purposes) disabling CPU C-States in the BIOS (assuming that setting is even available on this board) make any difference?

          1 of 1 people found this helpful
          • 2. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
            ncuster

            I have ensured (and checked again, since you asked) that I have the latest BIOS update for the board installed.  I didn't have the "C-State" as an option in/of itself, but C-State was mentioned in a setting that was something like "Power Monitoring" (don't remember the exact setting name).  I turned that off and it may have helped some, but didn't eliminate the problem.

             

            To answer your next question, no, the problem is not audible on standby, but is constant when the system is awake.  However, I have noticed some fluctuation and perhaps even an increase in volume when there is graphic activity (anything on the monitor changing)...

            • 3. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
              k00zmi4

              Here's my 5 cents...

               

              I'm having exactly the same issue with my rig (exception - I use DacMagic USB). Intel forums were the last place I would've expected to find discussion regarding this...

               

              Anyway, the good news is - it has nothing to do with your motherboard or USB Audio.

              The bad news - it's your PC's PSU causing hum; though you might notice it, being close to your mobo/VGA card/even cooling fans, the source is the PSU! (I've taken mine apart to confidently define the noise source).

               

              The cause - improper ground looping at your rig, or even, more probably, house power outlets. Since I don't have 3rd ground wire connection at my house, I'm pretty much sure about mine. This would explain you not having issues at work (PC - power sockets most probably done the right way, different PSU; Notebook - cleaner DC voltage if on battery; external PSU usually has 2 pins, not picking emi intereference via ground line)

               

              A way to check for overall confidence: while all devices (PC+Behringer) being connected to the same wall outlet, try reconnecting Behringer's USB cable to your PC, but not actually plugging it in, - just merely touch the metal part of your pc case/usb sockets, whatever... While playing audio (meet the hummin' conditions whatever way), the noise should be present. Now shut down your PC and reconnect its PSU cable to a totally different power socket - it must not 'meet' the one where the Behringer's connected! It might be little complicated if you don't know your house's electrical wiring schematics, just try different (all possible) ones in case of fail, might need a cord extension though. The noise should be gone.

               

              You can also try separating the PC's display - Behringer power sources the similar way. Could be the display's power supply, but less likely.

               

              I've finally ended up using optical spdif input for pure sound.

               

              Good Luck!

              • 4. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too

                Thank you very much.  Your reply made sense.  The Behringer interface is only powered through the USB, but the PSU on ungrounded looping through home outlets makes sense and everything about why I don't get it at work does also.  I've read that you should have dedicated and grounded circuits for a home studio, and I guess this is just one of the reasons why.

                 

                I have everything on my rig on a somewhat dated, but reliable APC UPS, so I thought that might be producing it, but if its plugged into non-grounded outlets in a home setting, I guess that's my fault.  What is fortunate is that I have a neighbor who is a licensed electrician.  I guess its time to get that dedicated, grounded circuit put in!  Thanx again...

                • 5. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
                  Flying_Kiwi

                  ncuster wrote:

                   

                  I have ensured (and checked again, since you asked) that I have the latest BIOS update for the board installed.  I didn't have the "C-State" as an option in/of itself, but C-State was mentioned in a setting that was something like "Power Monitoring" (don't remember the exact setting name).  I turned that off and it may have helped some, but didn't eliminate the problem.

                   

                  To answer your next question, no, the problem is not audible on standby, but is constant when the system is awake.  However, I have noticed some fluctuation and perhaps even an increase in volume when there is graphic activity (anything on the monitor changing)...

                  Sorry about the delay replying. It does sound more and more like the issue I'd experienced with the DG45ID but I do think it's important to establish exactly where the noise is coming from. It'd be handy if you have a doctors stethiscope (sp?) or otherwise a microphone you can move around inside the case while you're listening to the resultant sound through headphones. I do think it'd be worth contacting the USB devices manufacturer as this may turn out to be a known issue with certain motherboards and THEY may have developed revised firmware to address the issue (if possible). CPU C-State is a setting under the Power related menu options on my DG45ID so I think you found the correct one. Some people with DG45IDs reported that disabling C-States here, eliminated the noise problem so check again and see whether there really is any difference at all.

                   

                  FWIW my intial suspicions with my DG45ID based PC were that the PSU was to blame (if for no other reason than simply because there are so many high frequency components in there) but this turned out to be totally unrelated in my case and a new motherboard with the latest BIOS made the world of difference while the PSU remained unchanged. You could always try moving your PC to test it in another location before calling in the electrician (and incurring possibly big bills that may not make a difference to the problem).

                  • 6. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
                    k00zmi4

                    ncuster, have you tried starting up your PC with Behringer on APC's reserve power (battery)? Is the noise still present? You can try starting everything up via the wall socket, except for pc (PSU) running on APC's battery and vice versa. That's basically the same thing I mentioned with socket swap earlier, just less fuss. And APC has internal filtering...

                     

                    The idea with stethoscope sounds rather fun to try... I might have used it inside the PSU, establishing the exact psu component making noise. But since I don't have one, my ears served me right inside the pc case. Though I did have to remove/replace components to 'hit the PSU'. Yeah, the Graphics cards were the loudest under load - just had to insert my old htpc's 8400gs (passive cooling) to find the problem persisting. Oh, and mobo swap didn't make no change.

                     

                    With the BIOS, the only setting, causing EMI noise I've heard of is 'spread spectrum'. Though any power related stuff might put extra load to psu's 12v rail, causing hum the way as with intense graphics.

                     

                    Oh, ncuster, another thing... Don't start blaming your psu, and search for a new more expensive one. This might not just solve your problem, it could even make it worse. Just google or run through some youtube links, and you'll find people with similar/even worse noise problems, using top of the notch corsair, antec, tagan (the one, which bugs me)) and other 'high end' stuff.

                     

                    The reason I decided to get into this discussion at the first place, is 'cause i pin pointed my problem about a couple of months ago, and finding someone with similar problem and using audio interface via usb was the reason too. Upon research done earlier, it was a hard job, since people mentioned the problem, never posted back with the solution, either the threads were outdated. While the number of suggestions didn't give a straight-forward solution.

                    • 7. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
                      ncuster

                      Without the use of a stethoscope, just moving my head back and forth along the backplane of the system, I can tell the noise is being generated from the area of the video connection, not the PSU.  I'm thinking, since high end video is not a big priority for me on this system, I'm probably going to get a lower end video card and disable the built-in video and see if this fixes my issue first.  Since I have different PSU's and UPC's on these two systems, but everything other than the type of monitor attached is identical, it seems more likely to me that this is an issue with the on-board video.  I'll keep you posted.

                      • 8. Re: High Frequency MB Noise - USB Audio Interface Picking Up Too
                        k00zmi4

                        ncuster wrote:

                         

                        ... just moving my head back and forth along the backplane of the system, I can tell the noise is being generated from the area of the video connection, not the PSU...

                         

                         

                         

                        That's exact mistake I've run into. The loudest component, making our emi noise is the video card. Only after PSU dissasembly, I pin-pointed the real noise source. Also, the PSU makes noise audibly quiter, but it kinda amplifies at the video card;)

                         

                        ncuster wrote:

                         

                        I'm thinking, since high end video is not a big priority for me on this system, I'm probably going to get a lower end video card and disable the built-in video and see if this fixes my issue first.

                         

                         

                        Yeah, give it a try. As I posted earlier, I tried 8400GS (no fan version) and the noise being listened to at the video card level was gone, but still present at the PSU and the DAC output.

                         

                        ncuster wrote:

                         

                        Since I have different PSU's and UPC's on these two systems, but everything other than the type of monitor attached is identical...

                        The bold part marginally directs the problem parts;) That's if you mean the home/office PCs by 'these two systems'

                         

                        ncuster wrote:

                         

                         

                        I'll keep you posted.

                        Much appreciated... And looking forward for your reply, hopefully finally solved.