Capacitor whine through powered Yamaha speakers

[KagedFC]

So I have this really annoying issue, and decided my first post ever on Anandtech will be on the subject.

I have a desktop that I built for Windows Gaming / Programming with a small hard drive inside dedicated to a Hackintosh build for audio production. (i7 870 @ 2.93, Gigabyte GA-P55-USB3, 8GB RAM, Diamond Radeon 6970, Corsair 650w PSU). I currently use a Firewire Presonus Firestudio Mobile as an sound card / audio input device, which I use both with Windows and OSX. Now here's the problem:

Something in the computer "whines" whenever I am loading something from a hard drive, opening a window with my mouse, etc. I hear it audibly directly from inside my computer, but ALSO through any 'powered' speaker, meaning any speaker / device that has its own power supply separate from the computer. (The Presonus is powered through the firewire cable). However, I do not hear the whine through my headphones. The audible noise is audible through the speakers not only through the Presonus, but also the onboard audio as well. I tested the Presonus with my speakers using my housemate's laptop and there is no noise whatsoever.

My guess is that there is a grounding issue of some kind, and when I googled my problem there seems that there are several reasons for capacitor whine, so if anyone can help me go in the right direction from here that would be great. My end goal is to remove the whine ONLY from my speakers, but if I could end the whine on the capacitor itself that would be great too. The whine from my computer is not too audible, thanks to my Fractal Design R3 case

 

[William Gaatjes]

Hello to AT forum.

My first suggestion would be :
Try turning of your power save features of the CPU.
Then see if it makes a difference.

 

[uclabachelor]

So I have this really annoying issue, and decided my first post ever on Anandtech will be on the subject.

I have a desktop that I built for Windows Gaming / Programming with a small hard drive inside dedicated to a Hackintosh build for audio production. (i7 870 @ 2.93, Gigabyte GA-P55-USB3, 8GB RAM, Diamond Radeon 6970, Corsair 650w PSU). I currently use a Firewire Presonus Firestudio Mobile as an sound card / audio input device, which I use both with Windows and OSX. Now here's the problem:

Something in the computer "whines" whenever I am loading something from a hard drive, opening a window with my mouse, etc. I hear it audibly directly from inside my computer, but ALSO through any 'powered' speaker, meaning any speaker / device that has its own power supply separate from the computer. (The Presonus is powered through the firewire cable). However, I do not hear the whine through my headphones. The audible noise is audible through the speakers not only through the Presonus, but also the onboard audio as well. I tested the Presonus with my speakers using my housemate's laptop and there is no noise whatsoever.

My guess is that there is a grounding issue of some kind, and when I googled my problem there seems that there are several reasons for capacitor whine, so if anyone can help me go in the right direction from here that would be great. My end goal is to remove the whine ONLY from my speakers, but if I could end the whine on the capacitor itself that would be great too. The whine from my computer is not too audible, thanks to my Fractal Design R3 case

Your issue is not called "capacitor whine", rather it's a grounding issue with either your powered speaker or your sound card, or both.

The reason why you don't hear it with your headphones is because the noise from the system appears as common-mode noise in the device powering the headphones, and is usually attenuated quite a bit by the amplifier/circuitry for the headphone.

The whine from the powered speakers can be due to the design of the speakers, from a grounding issue on the AC line, the sound card, or really cheap signal cables (ie, rca or 3.5"mm cables).

The easiest things to try is to power everything off the same power strip and/or replace the audio cables with a different brand. If your powered speakers has balanced inputs like XLR, try using that instead (XLR+ is signal from the sound card, XLR- is ground from the sound card, leave the XLR neutral unconnected). You'll lose 3dB of output but the balanced input will certainly fix the noise issues.

 

[KagedFC]

Your issue is not called "capacitor whine", rather it's a grounding issue with either your powered speaker or your sound card, or both.

The reason why you don't hear it with your headphones is because the noise from the system appears as common-mode noise in the device powering the headphones, and is usually attenuated quite a bit by the amplifier/circuitry for the headphone.

The whine from the powered speakers can be due to the design of the speakers, from a grounding issue on the AC line, the sound card, or really cheap signal cables (ie, rca or 3.5"mm cables).

The easiest things to try is to power everything off the same power strip and/or replace the audio cables with a different brand. If your powered speakers has balanced inputs like XLR, try using that instead (XLR+ is signal from the sound card, XLR- is ground from the sound card, leave the XLR neutral unconnected). You'll lose 3dB of output but the balanced input will certainly fix the noise issues.

I am currently using balanced TRS cables for my speakers (they are Yamaha HS50m http://www.sweetwater.com/store/detail/HS50M), and ironically enough when I use anything except my computer there is absolutely no noise, and there is no noise from my friend's Macbook using the same device and my own speakers. I did guess that it was a grounding issue. There is an audible whine from the computer itself (without the speakers on) and with the speakers turned on they "mirror" each other, if that makes sense.

Hello to AT forum.

My first suggestion would be :
Try turning of your power save features of the CPU.
Then see if it makes a difference.

Thanks! I will try that now.

 

[KagedFC]

Alright, I turned off the CPU power saver feature (some C3/C6 BIOS thing) and...no noise! <3 I'll definitely be sticking around on these forums!

 

[William Gaatjes]

Alright, I turned off the CPU power saver feature (some C3/C6 BIOS thing) and...no noise! <3 I'll definitely be sticking around on these forums!

Yay. ^_^
As soon as you mentioned that it happened only when opening windows or moving the mouse, i knew it was the CPU power consumption. That is the problem with systems that ramp up and down all the time in frequency and power consumption. We are talking about power consumption spikes of 100W in microseconds. Yay Electromagnetic interference. Instead of matching the computational power to what is needed by using a specific clock in a free to chose range, the cpu is turned on to full throttle and then put to low throttle again by use of a small selection of clock frequencies. The ramping up and down in power is what you hear. At least that is what i assume.
What you can try is see if in your case some audio cables are close to power cables (24 pin and 4 pin, sata powercables) or close to the CPU and main pcb. Try keeping the audio cables if placed as far apart as possible from power cables and the main pcb in the computer case.




According to wiki :
http://en.wikipedia.org/wiki/SpeedStep

V1.1 is used by second generation Pentium III processors. It enables the CPU to switch between two modes: high and low frequency. This is done by modifying the CPU's multiplier. A 1 GHz Pentium III consuming about 20 watts could be reduced to 600 MHz which reduces the power consumption to about 6 watts.

V2.1 (Enhanced SpeedStep) is used in Pentium III-Mobile processors and is similar to the previous version, but in the low frequency mode the CPU also uses a different voltage than the high frequency mode.

V2.2 is adapted for Pentium 4-Mobile processors. With this, a 1.8 GHz Pentium 4-M consuming about 30 watts can lower its frequency to 1.2 GHz, thus reducing power consumption to about 20 watts.

V3.1 (EIST) is used with the first and second generation of Pentium M processors (Banias and Dothan cores, used in Centrino platforms). With this technology, the CPU varies its frequency (and voltage) between about 40&#37; and 100% of its base frequency in increments of 100 MHz (for Banias core) or 133 MHz (for Dothan core). With this technology, Intel also introduces realtime Level 2 cache capacity variation, further improving power savings.

V3.2 (Enhanced EIST) is adapted for multi-core processors with unified Level 2 cache.

You have an I7, i would think you have speedstep V3.1 at least. But there is also the issue of the OS using power consumption correctly.

The people in the CPU thread have more knowledge then i do about these kinds of issues. Might be a bios update or a specific power management setting in the OS you use. However, i expected this issue since windows vista arrived. I remember there was an issue but that it was solved already. My advise is to ask the people in the CPU thread about this issue. Because if your CPU is running at full power all the time, it consumes a lot of electricity for nothing. If it is not solvable, try to find a program that you can turn of the cpu throttle in windows when needed and that you can turn it on again when not needed. Good luck... ^_^.

 

[jaywaltm]

Wow, I had this VERY same problem, using KRK powered speakers, Reason 6.0, and a Balance ASIO audio input device. Running W7 and the same MOBO as the user who posted here. Strangely, I was picking it up on recording my guitar, via the 1/4" input. But also noticed it when scrolling across web pages, it got worse while scrolling.

And turning off the CPU power save feature worked! (BIOS > Advanced CPU Core features > "C3/C6/C7 State Support" [setting to Disable].

And geez, after I went out and bought a brand new PSU too.

FWIW, I also was able to go into Windows power management, advanced power management features and adjust the Max or Min of the CPU power adjustment and noticed the problem vary as well, so between this forum and that one, it was clear it was related to the CPU power on some level.

Thanks all!

 

[Modelworks]

The problem you are having is not caused by capacitors or power supplies, it is caused by RF signals inside the PC and around it piggy backing on the wiring from the pc, then amplified by the audio amp. When you disable the power saving you lower the RF noise being created.

To remove the noise you need to stop those RF signals from being able to propagate down the wiring. The easiest way to remove RF signals is to use a choke on the wiring. Radio shack sells a good set of chokes for $3.
http://www.radioshack.com/product/index.jsp?productId=3012599

Put one choke on the wire just after it plugs into the pc and the other choke on the wire just before it enters the speakers.