Noise coming from speaker before loading game

[molehole2003]

So I have searched this forum for help on this issue and found some others have had somewhat similar issues. I haven't really solved the white noise issue but have found some info that might be useful for people with similar issues. I noticed that my speaker was making a minor popping sound from the time that the splash screen started until I loaded a rom in an emulator or went into one of the setup menus (i.e. raspi-config / setup / etc.). Once a rom was loaded the sound works great and once exiting the rom the popping sound was gone. 

Headphones = Great no white noise ever
HDMI = Great no white noise ever

When using WiFi I can hear some minor popping due to interference but that is a non problem due to the lack of using WiFi most of the time (and my eventual plan to turn off WiFi).

My current fix to this problem is using a splash screen video that has sound. For some reason once a sound is played the popping sounds are completely gone. 

I will play around with some more setting and testing once I finish loading my sd card. Hoping that maybe disabling WiFi might help. If anyone else has ideas I would be glad to test most things before putting the screws back in my case. 


Build information: Zero W build with WiFi obviously turned on. Pictures to be provided (in the other part of the forum) once I finish tinkering with the sd card.

[SabithaSuki]

This is a direct result of the placment of the speaker. If it is not steadily placed down (IE the included pad) it will have white noise in the menus due to its constant-activity polling.

[Flavor]

The white noise is a known issue. It seems more obvious on some builds than others. One thing that "solves" it for some people is to play with the balance between software volume and hardware (thumb wheel) volume. You can set the software volume from the main menu (tap START after bootup, IIRC). Try turning it down or up and then rebooting.

The fix of playing a splash bootup video is also a good one. What happens is that the software tells the Raspberry Pi to set these outputs to PWM for audio, but it doesn't necessarily initialize them to anything until the first audio is played. Prior to that they are just "floating" and are more susceptible to outside noise influencing them.

The HDMI uses a different output, so that's unaffected by this.
The headphones actually use the same output, but they are un-amplified. It's the amplification of the noise that you are likely hearing.