[SOLVED] RPi 5 - strange noise problem

[duke.g]

Hello everyone,
I have a strange problem. I am using an RPi 5 with 4GB and an SMSL D12 USB DAC. I'm using Moode 9.03. I hear noise and whistling between songs. This changes when I browse through the library, for example. When I connect the DAC to an RPi4, there is absolute silence when no music is playing or between songs. On the RPi4 I also use 9.03. So it can't be the DAC. I have already tried all USB ports on the RPi5, with and without resampling, with and without Camilla DSP etc. Bluetooth and WiFi are both off.
Does anyone have any ideas what else I could try?
Any suggestions are welcome.

Regards
  Duke.G

[Tim Curtis]

What model power supply are u using?
Are there any accessories attached to the 5?

[duke.g]

What model power supply are u using?
Are there any accessories attached to the 5?

Hi Tim,
I use the Standard Raspberry Powersupply for the Pi and a separate Supply for the DAC. There are no additional gadgets attached to the Pi. I also tried different SDs. There is nothing suspect in the logs.
Could it be that the Pi itself has a Problem? BTW I use the Standard Pi active Cooler.

Thank you very much for your interest and support.

Regards
   Duke.g

[Tim Curtis]

Very odd. I haven't experienced any audio noise on any of my Pi-5's.

When you say "Standard" power supply I assume you mean the specific 27W USB-C PD supply for the Pi-5, correct?
https://www.raspberrypi.com/products/27w-power-supply/

[duke.g]

Very odd. I haven't experienced any audio noise on any of my Pi-5's.

When you say "Standard" power supply I assume you mean the specific 27W USB-C PD supply for the Pi-5, correct?
https://www.raspberrypi.com/products/27w-power-supply/

The one for Germany, but yes, it is the Standard one.
Is there anything else i can check, apart from buying a new RPi?
The Dac also works well on my PI 3B.
I also changed all the cables...

But don't think too much about it. If no one else ever had such a problem, the PI might be defect.

We are talking about this DAC:
https://www.androidbrick.com/smsl-d12-akm-dac-amp/

[Tim Curtis]

When you test the Pi-4 which has no glitches are u using the Pi-5 power supply?

Generally with these types of odd noise issues swapping PSU, Pi etc can help isolate the issue.

[DRONE7]

The symptoms would indicate a ground loop or similar, especially as noise is increased by browsing activity.
I see you use the Official Pi power supply. What about the DAC power supply ? Can you try another supply with the DAC ?

Not familiar with German mains connection format but assume they include mains earthing for both supplies ?
Are both power supplies powered from the same outlet ?

Have you temporarily disconnected the Cooler to check that is not the culprit. Things like fans can put noise back on the power supply and as your Pi4 is quiet I wonder if testing the cooler is useful to eliminate it being the problem.

[duke.g]

The symptoms would indicate a ground loop or similar, especially as noise is increased by browsing activity.
I see you use the Official Pi power supply. What about the DAC power supply ?  Can you try another supply with the DAC ?

Not familiar with German mains connection format but assume they include mains earthing for both supplies ?
Are both power supplies powered from the same outlet ?

Have you temporarily disconnected the Cooler to check that is not the culprit.  Things like fans can put noise back on the power supply and as your Pi4 is quiet I wonder if testing the cooler is useful to eliminate it being the problem.

Well I found the culprit. It was the connection to the display. I sometimes use a TV as local display. After I disconnected the cable the silence was back!!
Many thanks for all the suggestions.

Regards
   Duke.G