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Mojo as Desktop DAC Troubleshooting

Liberte

Member
Joined
May 2, 2022
Messages
27
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8
Hi there,


I wasn't sure which section to post in so hopefully this is ok here.

I recently picked up a Chord Mojo, it sounds fantastic but I'm having one issue. When using it as a preamp for powered monitors with computer as the source, I get a high pitched noise coming through. With headphones (still using computer as the source) there is no high pitched noise, and using a phone as the source (listening through powered monitors) it is also fine, so it seems to be only an issue when the Mojo is between computer and powered monitors. With the audiolab M-DAC the sound is fine and I can just about hear the high pitched noise with the HiBy FC3.

I have a USB isolator, but the Mojo won't connect even though its supposed to only use data from its USB connection. I'm thinking perhaps the iFi USB isolator with a 5v power source may do the trick?


Thanks for any advice on this.
 
Last edited:

mokanu

Member
Joined
Jul 6, 2021
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1
Looks like there is a ground loop or some source of EMI connected to or inside your computer. I had similar issue with external display, it was salved by connecting the display to an outlet without ground contact.

USB isolator may also help.
 

twsecrest

Addicted to Fun and Learning
Joined
Nov 27, 2018
Messages
758
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249
Location
California
Hi there,


I wasn't sure which section to post in so hopefully this is ok here.

I recently picked up a Chord Mojo, it sounds fantastic but I'm having one issue. When using it as a preamp for powered monitors with computer as the source, I get a high pitched noise coming through. With headphones (still using computer as the source) there is no high pitched noise, and using a phone as the source (listening through powered monitors) it is also fine, so it seems to be only an issue when the Mojo is between computer and powered monitors. With the audiolab M-DAC the sound is fine and I can just about hear the high pitched noise with the HiBy FC3.

I have a USB isolator, but the Mojo won't connect even though its supposed to only use data from its USB connection. I'm thinking perhaps the iFi USB isolator with a 5v power source may do the trick?


Thanks for any advice on this.
Make sure the computer and the power monitors are on separate surge protectors (power strips).
 
OP
L

Liberte

Member
Joined
May 2, 2022
Messages
27
Likes
8
Make sure the computer and the power monitors are on separate surge protectors (power strips).
Thanks for the tip, the Topping USB isolator works well but I'll bare this in mind for the future.
 
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