Having strange audio issues with an AKiTiO + GTX 980 on a Macbook Pro

[IMUR]

Hi everyone... This is my first post here, and I'm desperate.

After some experimentation and luck, I get a consistent startup, and no glitches from the eGPU setup.

The issue is; that there is a buzz that comes from my monitor speakers whenever something changes on screen. The more dramatic the change, the more consistent/loud the buzz becomes.

It sounds a bit like a cell phone, using data, is placed next to the speakers.

the Audio interface I'm using seems like the culprit at the moment, but I cannot be sure.

The setup is as follows:

- GTX980 in a AKiTiO going thunderbolt direct into my Macbook Pro Retina.

- Apogee Ensemble audio interface firewire 400 into the firewire 800 port of a thunderbolt 1st gen Belkin thunderbolt hub (I tried the same configuration with the latest OWC; same results).

- Belkin hub into the second thunderbolt port on my computer.

After some trouble shooting, I've got a few things that have helped, and a few that did nothing.

Attempts that did nothing:

- Rearranging the thunderbolt signal flow, i.e: Hub into AKiTiO into Comp, AKiTiO into Hun into Comp, and so on.

- Changing output signals from the audio interface.

- Swapping thunderbolt inputs on the computer, the hub and the AKiTiO

- Testing different power sources, i.e: Grouping all to one outlet, using separate wall outlets for the AKiTiO and interface/Hub, and various implementations of power conditioners.

Attempts that seemed to help (slightly):

- Placing the AKiTiO further away from the interface.

- Changing the power outlet for the monitor speakers.

I know that this is a strange problem, and it could very well wind up being a quirk in my setup alone, but I just wanted to know if anyone has experienced this or has any advice at all; I would really appreciate it.

Thank you,

- IMUR

[Dschijn]

Is the eGPU placed openly in the AKiTiO without any case around it? Could be electromagnetic interferences.

[IMUR]

A bit, yes... Since the card is larger than the intended length; it sticks out quite a bit from the back.

Do you suspect that the card may be effecting the speakers directly?

[Dschijn]

I think Firewire is using the outer case of a computer as a ground. Maybe there are signals passed through that to the audio interface.

Can you shield the eGPU a bit? Maybe simply place a "wall of aluminum foil" between the eGPU and the MacBook + audio interface.

[Jakeith]

Having the same issues w/ my setup;

2014 Macbook Pro 15" w/ Retina+

Akitio Thunder2+

GTX 980Ti+

Focusrite Scarlett 18i20 Audio Interface.

 

With everything plugged in, and no stress on the GPU, there is no noise/interference.

 

When GPU is under stress; through rendering, gaming, etc. , there's interference/noise that correlates with the amount of stress to the GPU

IE: Low stress=very very little noise, Higher stress= more noise.

 

It isn't unbearable or anything, it's just annoying to deal with; pretty much only noticeable when there's no other audio playing. 

 

It's weird b/c...

When the audio interface is being plugged in (via USB) while powered off,

but my monitors/speakers are powered on, the interference can still be heard.

~ vs.

When the audio interface isn't plugged into my computer (via USB),

but my monitors/speakers are powered on, there's no interference at all.

 

My Akitio+GPU is less than a foot away from my audio interface, so I suspect it's from elctromagnetic interface like the dude above said.

 

Suggestions?

Edited January 24, 2017 by Jakeith

[Jakeith]

Think I found a solution the issue: