System listed below.
I use my motherboards soundcard for desktop audio. It is analogously fed into my audio interface. When opening an ASIO-using program (Cubase, Kontakt, Premiere etc.), my monitors start ringing at about 1600Hz. Upon further inspection I found, that the sound originates in the analogue connection from my motherboards audio output to my interface. I guess it is due to bad mainboard-design, but I’d like to discuss the issue before buying a new more expensive one.
Windows 10 Pro
AMD Ryzen 7 3700X
MSI B450-A Pro Max (latest BIOS-Update installed)
64GB DDR4 RAM @3333MHz
RME Fireface UC (connected via USB 2.0, latest driver & firmware installed)
There is no need to feed your onboard sound card into the RME interface’s analogue input. Doing this is probably leading to a ground loop, hence the noise, though it could just be that the output is noisy.
If you want Windows sound via your RME interface, set your default Windows sound interface to “Speakers (RME Fireface UC)” then, in Totalmix FX, click the output your speakers are on and fade up AN 1/2 in the Software Playback section.
Ok I forgot to ask how do you tested this?
Does the onboard audio produce this noise without the connection to the RME? (check it with headphones?)
If not, you probably produce a feedback loop, as others already mentioned.
There might be both a ground loop and a feedback loop here.
Connecting a cable from the line (or headphone) out of the sound card to the RME interface’s inputs is one ground. The data cable between the computer and the RME interface is a second ground between the two devices. Grounds should always be in a star topology. There is no need for the analog audio link between the two devices anyway - several of us in this thread have already said to use the RME interface for Windows audio. I gave full instructions in my earlier post on how to use the RME WDM device and Totalmix FX to mix audio output from Windows into the overall interface output.
There is only a feedback loop if Windows is somehow outputting part of the audio received on the RME soundcard input from the soundcard.
The important thing is for the original poster to stop using the soundcard, as it is not needed. Soundcard outputs are often horribly noisy, not helped by the substantial currents typical in motherboard ground and power planes.
Nah, a ground loop is either when none of the devices are grounded and their filtering circuits are poorly made (for example laptop + DC powered interface), or when your house is badly grounded or not having a ground at all, or when you use two different sockets, one for each device, and those two sockets are independently grounded, which means both have different potential and the current leak is making a loop, which is most probably not the case in your average house. The chances for a real ground loop to happen is much higher in large buildings and there are some videos on the internet showing that, notably this one : Sound system ground loop demonstration - YouTube
To this day people are still having a misconception of what a ground loop is.
I live in a house that is properly grounded, and all of my devices are grounded both from the sockets and from the cables connected between them, and I’ve never ever had any ground loop.
This isn’t the ground loop typical in defective audio setups that brings mains line frequency hum into the audio but it is still a possible ground loop. Remember that the digital and analog ground planes of the motherboard should be separated (with a single point of interconnection), which are not necessarily at the same potential and may have differing amounts of noise on them.
Ground 1: analog motherboard ground <-> interface analog input
Ground 2: digital motherboard ground <-> interface USB (or Firewire) ground
The analog and digital grounds will be tied together in the motherboard. Whether the analog input ground and digital input ground are tied together in the interface depends on the circuitry used.
A soundcard to audio interface cable will also be single-mode stereo, so is susceptible to interference induced onto the cable.
The sole ground is noisy because it is floating rather than tied to earth. The floating ground may pick up induced current from the mains leading to line frequency hum, but there is no ground loop. This is a situation where star-quad cables can help if the audio interconnect is balanced, as the cable geometry ensures that almost all interference is common-mode (and therefore removed by the balanced input).
Same as the previous example - noisy floating ground not referenced to earth rather than a ground loop.
Actual ground loop, as you say - but not the only way that a ground loop can arise in audio applications.
Quite. There are multiple ways that noise, including mains line frequency hum, can get into analog audio equipment. A problematic ground loop does not have to be a mains ground loop.
We seem to have drifted rather a long way from the OP’s problem.
This is actually the exact case where the induced noise isn’t the typical 50/60 Hz hum, but high pitched electronic sounding noise that is tied to your CPU activity.
I once had a laptop and a DC powered interface so none of them were grounded, and the noise increased in volume every time I was moving the mouse.
Such a thing would only occur if your run audio cables parallel and very close to AC cables over a long distance.
UPS transformers are more of a concern since the produced hum can be picked up by any guitar or microphone from several meters from the unit, but that is not the question.
The best would be the OP to record the actual noise and post it here so we can take a closer look.
A ground loop is not the reason for the problem I described. A ground loop would induce a permanent hum or ring whereas the 1600Hz ring only ever shows up, if and only if I use an ASIO program.
It is also not a feedback loop, because audio is never fed back. The ASIO programs and windows Audio are two separate sources that are summed by the interface. @st10ss I tested it by plugging the mainboard audio directly into my amplifier. The same problem shows when opening an ASIO program.
That depends on the routing in the interface. It’s easy to produce a feedback loop if the monitoring is done with the interface.
Did you checked Totalmix? I guess, you did, so back to my first statement… if it’s broken it’s broken…