D10, Mixer, Computer Ground Loop Nightmare

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Hey there,

Ok, so I’ve had a D10 with a Liquid Spark amp for quite some time now, it’s been great I’ve enjoyed it a lot. I recently upgraded my mic setup from a generic USB mic to a Mackie Mix8 analog mixer with 2 condenser mics I already had. This introduced quite the ground loop. With the mixer being grounded to the well, ground, and the DAC being powered by the computer, this wasn’t surprising. I was half expecting it anyways and decided to get the iFi iDefender with the iPower to power the DAC. This removed a huge chunk of it, but it left this high pitched ringing. I thought maybe it could be interference, so I threw some ferrite beads on my cables and that seemed to do the trick. It all was well and good for some amount of time. I think about a week or 2, until I noticed that when I played a youtube video, or any sound for that matter, a high pitched whine would come, then go away (quiet down significantly?) about 15 seconds after stopping whatever the source of the sound was.I’ve posted a picture of my setup, I’ll explain each line here:

Aux send to computer: This is what carries my mics, and sometimes my desktop audio to my computer. Like sometimes if people want music in a discord call, I can play Spotify and just turn up the aux knob. The way the Mix8 works is there’s an aux send, allowing any channel to be sent to the aux, allowing for routing. This is a mono 1/4" to 3.5mm cable with ferrite beads.

"Chat" audio to mixer: I push the output of things like Discord and Zoom here to my mixer. Allows me to play music without people hearing themselves. This is running off the internal Realtek chip in my computer. A 3.5mm to dual 1/4" jacks with a ferrite bead.

Mic in: 2 xlr inputs. I had two mics so figured why not use both?

" Desktop" audio: RCA output on D10. RCA to dual 1/4" with beads.

Unlabeled cable to amp: Same cable as on DAC, RCA to dual 1/4"

It’s worth noting I am running I think D10S (don’t quote me on that) or something like that instead of the D10 drivers. Someone in MassDrop comments said that and I thought I’d try it and didn’t see any problem in it. Also, for an unrelated reason, this is a fresh install of windows. So that eliminates a lot of factors as well.

I’ve for sure narrowed it down to the DAC, so it must be something with a ground loop, right? When I revert back to my old setup (computer to dac to amp) there’s no sound at all. (Which begs sort of a separate question, but why is there only a ground loop between the mixer and the dac? The mixer is plugged into the ground just as the amp is, so why isn’t there one between the amp and dac?) Anyways, I don’t think it’s drivers, I already reinstalled them. Anyways, help?

SIDENOTE: One thing I have found out is this mixer is pretty loud noise floor wise. I mean it was pretty cheap, around 80 bucks. I’ve been thinking about at some point changing over to the 802VLZ4, which is about 200 but maybe later. I already had gotten the wrong thing once, as the FX8 or whatever I got didn’t route how I wanted it to, and I didn’t want to wait around for another product when I already had to shuffle some stuff around to get where I am now. If you have any suggestions for mixers, feel free to let me know. I had just started with Mackie cus I knew about them and it wasn’t too expensive. I’m aware of the GoXLR, but I don’t want to spend 500 dollars on this. I know it’s sort of heading that way, but I’d like to avoid it if possible.

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I have a Mackie Mix12 hooked up 4-way to my computer (3 directly with analog, one via Balanced from my Scarlett 2i4). Setup

Yes, you have a mighty ground loop.
Behringer HD400 or ART CleanBox between mixer and computer should do. (Both require stereo to 2x mono 6.3mm Y-cables)

Could try a transformer isolator like the ART DTI

Inductors (your ferrite beads) resist a change in current. Analog audio is transfered as voltage with minimal current flowing. I am 80% sure this is the cause of the ringing.

Interesting.
With my headphone amp (ART HeadAmp4 → M40x) at normal listening volume, pad switch pressed +10dB on the channel and +10 on the main, there is very low noise for me.

Depends on what you want to achieve.

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Thanks for your reply, I’ll look into getting an HD400. Would I need this on both connections to my computer (The Aux send and the chat audio line)?

I’ll take the ferrite beads off then, that totally makes sense and I’m not sure why I didn’t realize that. Must have been something else then as to why the ringing went away. I was on a call with my friend and when I put it on he said the ringing got quieter, maybe when I plugged the cable in I just didn’t get as good of a connection and therefore not as bad of a ground loop? Idk

As far as the mixer’s concerned, I just want good quality sound and routing. Preferably routing that is in stereo, unlike the Aux routing on what I have now which is mono. Routing in some shape or form, allowing me to play music or desktop audio, or a synth or whatever. In a way that I can choose whether they hear it or not. Like now, since they’re on the aux send, I can hear everything but I choose what they hear.
In terms of the noise floor, it could be this ground loop in some shape or form. I didn’t see the ground loop coming from the aux send and the chat cable so I’m not sure if I unplugged those when I was troubleshooting. I was too focused on the loop concerning the computer, dac, and mixer.

There’s got to be an easier way to do this right? It’s not like I browse audio forums that much, but I haven’t heard of anyone get a massive ground loop like this. Overall, my goal here is to be able to use my two condenser mics, and route audio (through the means of a hardware device) so people can either hear things or not in a form that is not a GoXLR. So if theres a better way to do that, let me know.

EDIT: Just thought of something, I could just get one hum eliminator and put both the chat channel and the aux send through it since the aux is already mono and I don’t really care if voice chat is mono as well.

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Good thought.

There are some mixers that have the option to assign inputs to groups.

The cheapest one that does that is the Behringer Xenyx 1002B, no experience with it, but probably a downgrade from the Mackie.

Mackie VLZ4-series (except the 402) also have a Control Room grouping function.

The Alto Live2404 (Which I have experience with) has real groups, is extreme overkill for home use.

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Alright, so I was right in thinking of upgrading to the 802VLZ4. I did look at the Live2404 and yea, quite overkill lol. But it’s baby brother the Live802 looks really good. It even has a stereo aux send and a USB as well. Does Mackie and Alto tend to be the way to go for mixers like this then? Also, is this sort of ground loop issue typical? Is this just how it is trying to set something like this up?

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Those two are brands I have experience with. There are probably more options out there (could check Yamaha).

Note: I never used the USB function on Alto anything. So no idea if it is any good.

Sorta kinda.
Especially notebooks and computers tend to have this kind of problem.

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Ok awesome, thanks for the help! I think in reality I’ll wait on getting the HD400 until I upgrade to the Live802 since for now I can eq it out and I plan on getting the Live802 sometime around Christmas and that may bring other problems. Again, thanks!

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You are welcome. :slight_smile: