PC Sound card noise from CPU - Page 1
Forum section: electronics / general

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: September 17, 2022, 10:58:36 am
content: I have pretty annoying static picked up by my sound card, most likely from the power rail, that directly corresponds to the coil whine from the CPU chokes.the setup is as follows:AMD A10-7870k CPUESI ESP 1010 Sound cardFSP power supplyMSI A68HM-P33 V2 motherboardGTX 950 graphics cardI tried swapping the PSU for a more expensive Corsair power supply and to my surprise the noise was much worse, swapped back to the FSP cheapo and it was a only mild as was before.but it's still annoying.I tried underclocking the CPU but it didn't change the noise.I tried underclocking the GPU, thinking that maybe there was some filter chokes for the PCIe slots near the CPU and that I was hearing those, but no, didn't change the noise either.I was thinking of getting a PCI slot extender for the sound card and splicing some filter circuit on the 5V power rail, what do you think?and also, would it be the 5V power rail? if it's coming from the CPU it would make me think that it would be the 3.3V rail instead, but what would a sound card need 3.3V for?but the fact that the 12V phantom power for the mic inputs has the same noise on it would make me suspect the 12V rail, which would also feature a -12V rail, ideal for some opamps probably.also that noise is present on the output too, no matter what the volume is set to in the software control panel.

author: wraper
author_rank: Unknown
timestamp: September 17, 2022, 11:16:14 am
content: You could play with power saving features in BIOS. Always keeping CPU clock at maximum often fixes the issue but increases power consumption. The best way to get rid of this is changing the motherboard to something else but you never know if it will not have the same issue. Another option which worked for me well is making 1-2 turns of audio cable through a ferrite ring.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 17, 2022, 11:17:12 am
content: The CPU has it's own SMPS onboard, on the motherboard, right near the CPU. Usually more than one channel, easy to spot by the ferrite cores and electrolytic capacitors surrounding the CPU (being close to the CPU and SMPS MOSFETs they also work at high temperatures). Most probably those capacitors have dried with time.I'll try replacing the motherboard with a better model and sell the old one. Replacing the capacitors is usually tricky, and not guaranteed to work if the MB has a bad design.From BIOS, try enabling "spread spectrum" if there is any, might help.

author: wraper
author_rank: Unknown
timestamp: September 17, 2022, 11:27:13 am
content: Quote from: RoGeorge on September 17, 2022, 11:17:12 amThen you usually will get system instability. IME a lot of motherboards, especially older ones like OP has are just garbage in this regard straight out of the box. In the end I fixed it in the root, I use optical audio out for about a decade.

author: RoGeorge
author_rank: Super Contributor
timestamp: September 17, 2022, 12:00:54 pm
content: If you leave the ESI sound card plugged in, but use the onboard sound instead, does the onboard sound card has any CPU noises?

author: RoGeorge
author_rank: Super Contributor
timestamp: September 17, 2022, 12:30:25 pm
content: You shouldn't physically hear any noises from a good motherboard. From what you say it's the CPU SMPS's fault. I'll change the motherboard with a better model, one that has better or more stabilizer channels (and supports higher CPU consumption).I don't know what MB model to recommend for your AMD, but I can tell for sure some MB models are advertised as having better CPU stabilizers, like this one for example:https://www.asrock.com/mb/Intel/Fatal1ty%20Z97%20Professional/that's for Intel CPU, I know, but please note the features related with the onboard CPU powering and lower CPU noises:Quote

author: Twoflower
author_rank: Frequent Contributor
timestamp: September 17, 2022, 02:54:16 pm
content: I had a similar problem. It turned our, that at least a reasonably amount of noise, came from the GPU. And not via the supply but via magnetic(?) coupling between the cards itself. I inserted an insulated metal blade between the sound card and the GPU and the noise reduced very noticeable. The hint was that I could even hear the cursor blinking! And the noise showed 60Hz artifacts.With all that DCDC converter driving high fluctuating currents it's a hell of electromagnetic noise in the case. Up to 100A for the GPU and the CPU changing thousands times every second.In the end I returned the sound card and used an optical toslink adapter. And guess what: It was also an ESI Card. I don't remember the exact model, but it had an option to use symmetrical outputs by rotating a daughter card.

author: magic
author_rank: Super Contributor
timestamp: September 18, 2022, 10:03:28 am
content: If there is continuity from the ground of analog connectors to the rear metal bracket of the card, completely insulate the bracket from the computer's case (or the soundcard's ground) and see if it helps. These problems are usually caused by ground loops.Noise coming from motherboards is fairly normal. It's most likely caused by piezoelectric ceramic capacitors near the CPU.

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 18, 2022, 06:01:29 pm
content: I would go for a reasonable USB sound card and call it a day.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 18, 2022, 08:58:50 pm
content: I wonder why cheap PC speaker sets with optical TOSLINK for audio are so rare.The USB dongle needed is pretty darn trivial, and the receiver side and the DAC can be optimized for the actual drivers.Having seen some youtube videos on how good audio one can achieve with the actuators that attach to flat panels, it would be nice to build ones own for apartment flat use (i.e., designed not to conduct sound via walls, floors, or ceiling; only vibrate the air, and designed to achieve good acoustic response at low to moderate volumes). While typical PC speakers have good enough frequency response for me, their power supplies or cabling (picking up mains hum) is always so poor (or poorly shielded) that at the volume levels I use, the noise is annoyingly noticeable.

author: rdl
author_rank: Super Contributor
timestamp: September 20, 2022, 09:01:43 pm
content: I recommend USB also. I bought a used Audioquest Dragonfly years ago and it made a noticeable improvement in my set up.