Noise over USB when connected to external DAC, not a ground loop. At my wit's end.

[ggabriele3]

For the past few weeks I've been battling a problem were I'm getting noise through my speakers when my external DAC is connected to my PC via USB. I have done *extensive* troubleshooting and I believe I have narrowed it down to the PC itself (more detail below). The noise only occurs when the USB cable is connected to the PC (regardless of whether that source is selected on the DAC), and does not happen when I have only an optical connection to the DAC.

The noise is a constant volume; it does not change when I adjust Windows' volume or the DAC's preamp output volume.

Note, based on the troubleshooting below, I'm confident it's not a ground loop.

Setup Details: Gigabyte B150N/i5 6500 --> Audio-GD NFB28 DAC --> Amp --> Speakers.

Stuff that DID NOT fix the problem:
- Replacing USB / Analog cables in the chain
- using a different speaker amplifier
- Unplugging ALL other devices except for the PC/DAC/amplifier (including modem, wifi, etc)
- Using ground lifts / putting all devices on the same power strip / plugging the PC into the wall
- Running the PC with the HDDs (except a mobo-mounted M.2 drive), GPU, and front-panel USB disconnected
- turning off / unplugging the DAC
- Using different USB ports
- Using a powered USB hub
- Updating the BIOS, various drivers, disabling wifi/bluetooth, turning off bluetooth devices, etc

Stuff that CHANGED the noise:
- booting into the BIOS only (only noise came from keystrokes on USB keyboard)
- covering the USB cable's 1 & 4 pins with electrical tape
- using a different PC (less noise)

Stuff that STOPPED the noise:
- turning off the PC
- using ONLY an optical connection to the PC
- using a macbook instead of the PC
- using a different USB DAC connected to the same PC
- using an analog isolator between the DAC and amplifier

I'm out of ideas. I don't know what else to try here; I have contacted the DAC, PSU, and MoBo manufacturer and all are saying it's not their product causing the problem.

Can anyone offer any other ideas?

 

[rocktalkrock]

Have you gone into Device Manager and looked over all your drivers including USB controllers? Have you looked at "Control Panel > Sound" and right clicked "Properties" for each device listed in the "Playback" and "Recording" tabs?

 

[ggabriele3]

Have you gone into Device Manager and looked over all your drivers including USB controllers? Have you looked at "Control Panel > Sound" and right clicked "Properties" for each device listed in the "Playback" and "Recording" tabs?

Yes, I should have added some detail there:
- In Device Manager I have looked through; all of the USB controllers/hubs indicate they're working properly, and that "the best drivers for your device are already installed."
- I also recently uninstalled all disconnected devices from Device Manager.
- In Control Panel, I have disabled all Recording devices. The Playback devices all seem to be set up properly.

Am I missing anything?

 

[rocktalkrock]

Have you gone into Device Manager and looked over all your drivers including USB controllers? Have you looked at "Control Panel > Sound" and right clicked "Properties" for each device listed in the "Playback" and "Recording" tabs?

Yes, I should have added some detail there:
- In Device Manager I have looked through; all of the USB controllers/hubs indicate they're working properly, and that "the best drivers for your device are already installed."
- I also recently uninstalled all disconnected devices from Device Manager.
- In Control Panel, I have disabled all Recording devices. The Playback devices all seem to be set up properly.

Am I missing anything?

1. Have you updated to the latest Audio, Chipset and USB 3.1 drivers for your motherboard?
2. Have you looked through your BIOS settings. Try disabling "Audio LED" and "Audio DSP" on your motherboard.

 

[ggabriele3]

Have you gone into Device Manager and looked over all your drivers including USB controllers? Have you looked at "Control Panel > Sound" and right clicked "Properties" for each device listed in the "Playback" and "Recording" tabs?

Yes, I should have added some detail there:
- In Device Manager I have looked through; all of the USB controllers/hubs indicate they're working properly, and that "the best drivers for your device are already installed."
- I also recently uninstalled all disconnected devices from Device Manager.
- In Control Panel, I have disabled all Recording devices. The Playback devices all seem to be set up properly.

Am I missing anything?

1. Have you updated to the latest Audio, Chipset and USB 3.1 drivers for your motherboard?
2. Have you looked through your BIOS settings. Try disabling "Audio LED" and "Audio DSP" on your motherboard.

1 - I think all my relevant drivers are up to date. Device Manager ("update driver" in properties), Windows Update, the motherboard's driver download page, and the Intel Driver Support Assistant all seem to say that these are up to date (the Intel page indicated that there are updates for on-board wifi and bluetooth, though disabling those didn't have an effect when I was troubleshooting).

2 - I can try that when I get home, but note that I'm not using onboard audio - shouldn't that be entirely bypassed even if it was an issue?

(BTW, thank you for taking the time to help)

 

[rocktalkrock]

Have you gone into Device Manager and looked over all your drivers including USB controllers? Have you looked at "Control Panel > Sound" and right clicked "Properties" for each device listed in the "Playback" and "Recording" tabs?

Yes, I should have added some detail there:
- In Device Manager I have looked through; all of the USB controllers/hubs indicate they're working properly, and that "the best drivers for your device are already installed."
- I also recently uninstalled all disconnected devices from Device Manager.
- In Control Panel, I have disabled all Recording devices. The Playback devices all seem to be set up properly.

Am I missing anything?

1. Have you updated to the latest Audio, Chipset and USB 3.1 drivers for your motherboard?
2. Have you looked through your BIOS settings. Try disabling "Audio LED" and "Audio DSP" on your motherboard.

1 - I think all my relevant drivers are up to date. Device Manager ("update driver" in properties), Windows Update, the motherboard's driver download page, and the Intel Driver Support Assistant all seem to say that these are up to date (the Intel page indicated that there are updates for on-board wifi and bluetooth, though disabling those didn't have an effect when I was troubleshooting).

2 - I can try that when I get home, but note that I'm not using onboard audio - shouldn't that be entirely bypassed even if it was an issue?

(BTW, thank you for taking the time to help)

In your original post you said "Stuff that DID NOT fix the problem: turning off / unplugging the DAC". I assumed that meant the on-board audio was still active.

Have you switched the DAC between the USB 3.0 headers and the USB 3.1 header? USB 3.1 is controlled by an add-on ASMedia Controller. USB 3.0 & 2.0 are controlled by the chipset.

You also said earlier "Stuff that CHANGED the noise: booting into the BIOS only (only noise came from keystrokes on USB keyboard)". You could use a cheap USB to PS/2 adapter to plug your keyboard into the PS/2 port, to avoid any conflict between USB devices.

 

[ggabriele3]

Have you gone into Device Manager and looked over all your drivers including USB controllers? Have you looked at "Control Panel > Sound" and right clicked "Properties" for each device listed in the "Playback" and "Recording" tabs?

Yes, I should have added some detail there:
- In Device Manager I have looked through; all of the USB controllers/hubs indicate they're working properly, and that "the best drivers for your device are already installed."
- I also recently uninstalled all disconnected devices from Device Manager.
- In Control Panel, I have disabled all Recording devices. The Playback devices all seem to be set up properly.

Am I missing anything?

1. Have you updated to the latest Audio, Chipset and USB 3.1 drivers for your motherboard?
2. Have you looked through your BIOS settings. Try disabling "Audio LED" and "Audio DSP" on your motherboard.

1 - I think all my relevant drivers are up to date. Device Manager ("update driver" in properties), Windows Update, the motherboard's driver download page, and the Intel Driver Support Assistant all seem to say that these are up to date (the Intel page indicated that there are updates for on-board wifi and bluetooth, though disabling those didn't have an effect when I was troubleshooting).

2 - I can try that when I get home, but note that I'm not using onboard audio - shouldn't that be entirely bypassed even if it was an issue?

(BTW, thank you for taking the time to help)

In your original post you said "Stuff that DID NOT fix the problem: turning off / unplugging the DAC". I assumed that meant the on-board audio was still active.

Have you switched the DAC between the USB 3.0 headers and the USB 3.1 header? USB 3.1 is controlled by an add-on ASMedia Controller. USB 3.0 & 2.0 are controlled by the chipset.

You also said earlier "Stuff that CHANGED the noise: booting into the BIOS only (only noise came from keystrokes on USB keyboard)". You could use a cheap USB to PS/2 adapter to plug your keyboard into the PS/2 port, to avoid any conflict between USB devices.

I've tried connecting the DAC to a few different USB ports, including the front panel USB and an external powered hub. No change.

The USB keyboard I use is usually bluetooth - I only brought that up to point out the weirdness of there being *almost* no noise when I was in the BIOS pre-boot, except for a little blip of noise every time I pressed a key on the keyboard.

 

[rocktalkrock]

Take a look at the Audio-GD NFB-28 manual. Although it's a very poor English translation from Chinese, it suggests removing 4 jumpers inside the DAC to avoid possible conflict "between different sources". Try it and see if it helps.

"The NFB-28 had design the analog idle input short circuit for avoid the disturb between different sources."

http://www.audio-gd.com/Pro/Headphoneamp/NFB28/NFB28EN_Use.htm

 

[ggabriele3]

Take a look at the Audio-GD NFB-28 manual. Although it's a very poor English translation from Chinese, it suggests removing 4 jumpers inside the DAC to avoid possible conflict "between different sources". Try it and see if it helps.

"The NFB-28 had design the analog idle input short circuit for avoid the disturb between different sources."

http://www.audio-gd.com/Pro/Headphoneamp/NFB28/NFB28EN_Use.htm

Interesting find! that's the 2014 version but I found the 2014 version.
I'm not terribly hopeful about it, since that seems to be talking about "Input 5 or 6"; on the NFB-28, USB is Input #1.
But hey, it's worth a shot.

 

[rocktalkrock]

Take a look at the Audio-GD NFB-28 manual. Although it's a very poor English translation from Chinese, it suggests removing 4 jumpers inside the DAC to avoid possible conflict "between different sources". Try it and see if it helps.

"The NFB-28 had design the analog idle input short circuit for avoid the disturb between different sources."

http://www.audio-gd.com/Pro/Headphoneamp/NFB28/NFB28EN_Use.htm

Interesting find! that's the 2014 version but I found the 2014 version.
I'm not terribly hopeful about it, since that seems to be talking about "Input 5 or 6"; on the NFB-28, USB is Input #1.
But hey, it's worth a shot.

Perhaps turning off the "extra +6DB gain" would help.

 

[ggabriele3]

Take a look at the Audio-GD NFB-28 manual. Although it's a very poor English translation from Chinese, it suggests removing 4 jumpers inside the DAC to avoid possible conflict "between different sources". Try it and see if it helps.

"The NFB-28 had design the analog idle input short circuit for avoid the disturb between different sources."

http://www.audio-gd.com/Pro/Headphoneamp/NFB28/NFB28EN_Use.htm

Interesting find! that's the 2014 version but I found the 2014 version.
I'm not terribly hopeful about it, since that seems to be talking about "Input 5 or 6"; on the NFB-28, USB is Input #1.
But hey, it's worth a shot.

Perhaps turning off the "extra +6DB gain" would help.

So, those input jumpers didn't make a difference.
The 2016 version doesn't have the gain jumpers that the 2014 version had.
I also tried removing the actual USB jack from the case, just in case the jack's housing was interfering with the NFB28s case. No dice.

Even if there's no power cord connected to the NFB28, noise comes through to the amplifier when the USB cable is connected.

ugh.