[LAU] Ground loop noise problem using MSI H-97 Gaming 3 motherboard, SeaSonic SSR‑360GP 360W power supply.

Len Ovens len at ovenwerks.net
Mon Mar 6 16:14:15 UTC 2017

On Sun, 5 Mar 2017, john gibby wrote:

> Hi, 
> I have always had this problem with a little ground loop hiss, which I think I've
> traced down to the small current from the Power supply, used to keep the
> motherboard turned on.  If I plug my amplifiers in without their ground plug (not
> a good idea, I know), I can get rid of almost all of it.  I may go to a 6 d/a
> channel USB audio interface to get rid of it, but I wonder if anybody knows other
> things I can do; I wonder if it's just the design of this motherboard, or perhaps
> of this power supply.  If I knew for sure that some other motherboard would not
> have this problem at all, I might upgrade to it.  After a lot of testing, I am

Switching motherboards will change things, for better or worse is a 
crapshoot... I have found this both with internal audio and USB and in 
both cases the "better" MB was only better, not good. The first thing to 
remember is that audio and gaming are not the same. A better MB for audio 
is not the standard "upgrade". often a cheaper MB with fewer "bells and 
whistles" does better audio, has fewer things sharing irqs, has less 
"digital noise" floating around inside, etc.

> sure that there's a spurious signal included on the analog signals coming out of
> my computer's built-in sound card or PCIE card, that is trying to get to ground
> and causing the problem. 

Trying to get to ground? The inside of a PC case is noisey, even grounding 
aside. If you really want low noise... optical S/PDIF, ADAT, Firewire, PCI 
with external codecs, USB with PCIe dedicated USB port and maybe extra 
bits (I have not gotten good low noise with my USB AI... but for where it 
is... it allows my wife to use her stage mic and sound better than the 
internal) Get the audio bits outside of the PC case.

Really, a good PCIe Audio card is not cheap (~ $1k for 8 i/o) USB is 
cheaper... even with an extra cheap ADAT box.

Len Ovens

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