Noise from Pi 3 B + HifiBerry Digi+ Pro based Touch replacement

[Zoltan]

I built myself a Touch replacement about 3 years ago, based on a Raspberry Pi 3 Model B, a HifiBerry Digi+, and the official 7" touchscreen. This feeds into my Beresford DAC via optical link.

It has been fine for most of that time but recently I have been noticing a lot of noise. I would describe it as a slightly scratchy static-y sort of sound. It is not extremely loud but I am using headphones and it is is loud enough to be noticeable and annoying. It can be heard intermittently when no music is playing but it also happens consistently and very audibly just before/as a track starts.

I have a Chromecast and a CD player connected to the same DAC and I don't hear any noise from them. I took my old Touch out of retirement and put it in place of my self-built version (on the same DAC input) and this sounded absolutely fine.

Does anyone have any idea what might be responsible for this sort of noise and if there is anything I can try to correct it?

Thanks.

[Heuer]

Have you tried a a different PSU?

[Zoltan]

Have you tried a a different PSU?

No, I haven't. Is that a likely culprit? Unfortunately I don't think I have a spare one unless there is something I can repurpose.

I dug out my original order for parts and note that it is the "Raspberry Pi Official UK & EU Power Supply - 5.1V 2.5A". Should I buy another one of these or is there something better that it might be worth trying?

Thanks.

[bpa]

Assuming you are using PCP. You could try to see if the issue is hardware vs software and so try running raspbian and play audio. If noise goes away then issue is in PCP (or squieezelite player settings). If not then more likley h/w.

[Zoltan]

Yes, I'm using PCP. That sounds like a good idea in principle but I am going to have look into what I need to do. To be honest, I haven't tinkered with this stuff much; I put the player together three years ago and left it. I suppose that in itself might suggest it's not a software or settings issue? But anyway it makes sense to do what you suggest so I will have a go when I get chance. Thanks!