I run into a similar problem. I have a power-hungry GPU (3080) and CPU (9800X3D).
All my audio equipment was on the same UPS (and therefore outlet) as my gaming PC.
The result is that any time a particularly stressful game would be open, I'd get buzzing in the speakers. (Especially if the framerate was at 360) If you ask audiophiles online they will swear up and down that a cheater plug, balanced cables, or optical isolation will fix it - that will not fix it. It's not a ground problem. It's not coming from the connection from the PC to the DAC - it's a power issue.
It seemed almost inconceivable to them that the problem was EMI from the computer making it into the equipment.
I temporarily got a double-conversion UPS (converts AC to DC to AC again) and housed the audio equipment on that instead (separate from PC) Lo-and-behold the noise was completely gone.
However, those UPS are extremely expensive, and far worse they're very loud because the fans run constantly.
So, I went with a simpler alternative. Just get a power strip and plug all the audio equipment into that on a different outlet. That reduces it massively. You can also get some strips that are designed to reduce EMI, but I haven't felt the need as of yet.
If you're a bit handy, you can assemble a line filter using a part like this https://enerdoor.com/products/fin27/ for a heck of a lot cheaper than you can buy a filtered power strip.
Even if there's very little audio-frequency attenuation, it's possible for higher frequencies to produce audio-frequency intermodulation distortion, and filtering could reduce this. This is one reason "high definition" (ultrasound sampling rate) audio is a bad idea as a listening format.
In 2013 I bought out 2 Radio Shacks worth of ferrite beads when I was hunting down signal noise in my senior design project (CNC mill rebuild and update.)
All else fails, add more beads.
Also, I learned that you can make your own shielded flat cables with aluminum duct tape.
Who knew that they had a really good reason for using 48V signaling in the original machine controls from 1986?
Maybe you’re right. My experience is with radios, where it’s possible that high frequency noise is conducted into the RF section rather than into the audio amplifier. I know that in one case, both my transmitted signal and received audio output were absolute garbage (edit: because it was picking up noise from the vehicle ignition) until I added a choke to the power input wiring.
Well the OP’s electrical noise almost certainly is coming through the USB connection as their DAC has no external power supply. Extremely common.
Your problem of an AC power supply not sufficiently filtering out high-frequency noise from mains is exceptionally rare to the point that yes, I also don’t believe that was the correct diagnosis of your issue.
Pure sine wave UPSs are not that expensive anymore man. I think the biggest "desktop" pure sine wave cyberpower sells (1500VA/1000W, CP1500PFCLCD) is <$300 now. I have a couple of them, they are great.
It's not about pure sine wave - it's double conversion. Only double-conversion would actually isolate the equipment from EMI on the line. Without that pure sine wave won't do squat for EMI.
And one of those, even the cheapest ones, run for about ~$900. And they are LOUD.
Are they loud because they're double-conversion or are they loud because they're designed for server racks? When I search for double-conversion online I can practically only find rack-mount solutions.
They're loud because unlike a regular UPS they need to run continually to convert the power back and forth. That generates a lot of waste heat, which fans must remove.
I wonder if modern motor and power control tech could be adapted to make a desk-side motor-generator set that is efficient enough to rival an always-active, dual conversion AC-DC-AC UPS.
How efficient could a small AC->motor->generator->AC chain be with a modest flywheel mass to provide cycle-to-cycle stability?
Could it ever make sense to put one of these after a standby UPS so the output is always filtered by the motor-generator but the UPS only has to kick in for outages?
One advantage of a motor-generator set is that it's relatively easy to get high-voltage isolation using an insulating shaft. It might be possible to build something that could survive nearby lightning strikes to the incoming AC line. I don't think any standard UPS can do this.
The portable lithium battery "powerstations" double as great double-conversion UPS in addition to their intended outdoors (camping, beach, etc) activities, and depending on capacity go for less than 900 USD. It's only noisy when fast charging or providing high currents.
Definitely had various computer equipment plugged in to ours and it was great (I didn't specically test for EMI).
> If you ask audiophiles online they will swear up and down that a cheater plug, balanced cables, or optical isolation will fix it - that will not fix it.
Lifting the ground on my studio monitors absolutely fixed my noise problems. I run them off a MiniDSP 2x4HD, so other sources like EMI aren't really a factor.
The problem I have with a double conversion UPS is that it isn't an ideal sinusoidal source. It implies it is on the tin, but when you've got protected loads with PWM power delivery slamming around 1+ kilowatts, there's no way to guarantee a smooth waveform with a typical ~2500VA unit. Directly passing through to the grid could provide cleaner power under the most transient conditions.
It's not about isolation though - it's about line noise. An isolation transformer will let that pass straight through (minus the usual filtering due to any transformer being an inductor), whereas the AC->DC->AC conversion gets rid of all of it by effectively acting as a perfect low-pass filter.
Reminds me of my friend who has bought a shit load of 1.5v AA lithium batteries. The buck converters in those little bastards wreak havoc with every speaker around. His TV remote disconnects my Bluetooth headphones every time.
Sigh, it's almost like I had this conversation before.
My audio equipment is not connected by USB. It's connected by optical (TOSLINK) to an external DAC. TOSLINK is not great, but it shows that it is not a USB noise problem.
I got rid of the noise via the method I described in the original comment? Moving my audio equipment to separate power strip on a separate outlet. It didn't totally remove it, but made it quiet enough to deal with.
Don't mind them. I've had a similar thing happen, but with power line Ethernet. In your case however, I'd be at least a little concerned about the building wiring.
In many analog pro audio applications, it's actually recommended that a shield be connected at one side only, for this reason. By convention but not necessarily necessity, the bond is typically kept at the receiving end, as that's almost always a device with a grounded power cord (such as a mixer). Many DI boxes feature a ground lift switch as a convenient way to achieve this. But you wouldn't want to disconnect it at both ends, as then the shield has no effect at all.
Anyway, if you had problems with your unshielded cables that would be solved by a shield, but your shielded cables caused a different problem due to the bond at both ends, this technique of using shielded cables but severing the shield at one end of them would get you the best of both worlds.
Huh, I had no idea that cables would have their shield grounded at both ends... Single point ground is such a standard in electrical design that the guidance is generally "do otherwise only if you have the ability to make many prototypes to nail RFI issues".
If you're building an audio cable your signal will peak out at a few kHz, so the cable acting as an antenna and picking up a signal in the MHz range isn't an issue. Similarly, you're not transmitting anything significant either. But a ground loop can easily ruin your day.
If you're building a cable for multi-gbps data transmission, that ground loop noise might as well not exist - it's basically DC. But ground your shielding at only one end, and suddenly you're ruining everyone's wifi!
Building a device which needs high-speed data on one side, and analog audio on the other side? Good luck...
Ruled out the monitor(s)? There's been cases where they've backfed power, and they certainly backfeed EMI as well. And, it could also be tied to FPS- assuming gsync/free sync.
If you have a multimeter its probably worth double checking if the case is low resistance grounded to the end of the cord. I'm assuming you have checked already, but as a shock hazard it bares repeating.
I also have a splitter which lets you power an USB device from a separate power supply (i.e. D+/D- lines are connected to a host and +5V comes from a separate plug, ground is shared though). And optical TOSLINK is a nice option where available.
When I upgraded my PC to the same CPU, I had the same problem of crackling/buzzing speakers on my USB DAC (externally powered, but from the same strip/outlet) when the system was under load.
I had a hunch it was power related because my PSU was nearly 10 years old and probably with just barely enough wattage. I bought a new one and all the buzzing went away.
IIRC when I was researching possible causes, beefy Ryzen CPUs were the most commonly mentioned in various forums and reddit threads.
It depends some setups generate noise when you move a cabled mouse with a high resolution. I never measured it, but I would assume it is because of the high frequency signals of the mouse generates if it is actively used.
In that case more isolated cables and connections would probably help.
> It seemed almost inconceivable to them that the problem was EMI from the computer making it into the equipment.
I very much doubt that because audiophiles worries about a lot about both RFI, EMI and unwanted vibrations (I had one where I could hear a very faint metallic noise and it took me weeks to find the cause: a loose screw in the system ceiling a times vibrating a bit, depending on the song / passage in the song / frequencies and slightly touching a metal stud: horrible to diagnose but eventually I found it). For a start.
If you go on audiophile gear shops, you'll find power supply that, supposedly, prevent EMI.
Are RFI issues much more common? Sure. I had one in a previous place where I lived where simply lifting the speakers cable of the wooden floor would remove unwanted sounds: some kind of radio or TV program my cables would pick up. Then suddenly I stopped making fun of people lifting their speakers cable of the ground (but I'll still make fun of those paying $100 per little piece to lift their cables then buying 50 of these).
That said your comment is very interesting. But it also shows that, suddenly, power strips (or others) that try to deal with EMI, balanced cables (between various piece of audio gear), lifting $20 speakers cables off the ground, etc. don't look as idiotic as many make sound (ah ah). EMI, RFI and unwanted vibrations are a thing and they do ruin the listening experience.
All my audio equipment was on the same UPS (and therefore outlet) as my gaming PC.
The result is that any time a particularly stressful game would be open, I'd get buzzing in the speakers. (Especially if the framerate was at 360) If you ask audiophiles online they will swear up and down that a cheater plug, balanced cables, or optical isolation will fix it - that will not fix it. It's not a ground problem. It's not coming from the connection from the PC to the DAC - it's a power issue.
It seemed almost inconceivable to them that the problem was EMI from the computer making it into the equipment.
I temporarily got a double-conversion UPS (converts AC to DC to AC again) and housed the audio equipment on that instead (separate from PC) Lo-and-behold the noise was completely gone.
However, those UPS are extremely expensive, and far worse they're very loud because the fans run constantly.
So, I went with a simpler alternative. Just get a power strip and plug all the audio equipment into that on a different outlet. That reduces it massively. You can also get some strips that are designed to reduce EMI, but I haven't felt the need as of yet.