kas03
Posts: 4
Joined: Mon Aug 20, 2018 12:29 am

Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 12:36 am

So I installed LibreELEC on my Raspberry pi 3 and am using the 3.5 jack for audio / video ( using an old CRT monitor ). Problem is i have crackling / static audio humming in the background of my video audio, picture displays fine though. I've seen suggestions for updating the audio drivers of the pi but am not sure how to do this with LibreELEC installed. Would i need to boot linux off of a flash drive to install the drivers that way or is there an easier way to get the updated audio drivers? Brand new to the pi so am kind of lost.

ghans
Posts: 7806
Joined: Mon Dec 12, 2011 8:30 pm
Location: Germany

Re: Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 4:39 am

The audio driver on the Pi has been improved several times over the years. Some of the improvements are actually inside the firmware (start.elf) instead of the Linux kernel.

Updating the firmware (and the Linux kernel) is usally done with the "apt-get" command nowadays. Sadly LibreELEC is notorious for not supporting the "apt-get" mechanism. You can try replacing start.elf (copy-paste works) with its counterpart from here: https://github.com/raspberrypi/firmware.

This copy-paste can also be done from Windows ! (Do not take that for granted. Windows goes great lengths to ignore that Linux exists and to remian subtly or staunchly incompatible.)
Especially any indication that your SD card has been shrunk to a few megabytes is nonsense,
Linux will show you that all remaining space has been properly allocated in a Linux format called "ext4" which Windows tends to ignore.

ghans
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fruitoftheloom
Posts: 17663
Joined: Tue Mar 25, 2014 12:40 pm

Re: Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 7:15 am

kas03 wrote:
Mon Aug 20, 2018 12:36 am
So I installed LibreELEC on my Raspberry pi 3 and am using the 3.5 jack for audio / video ( using an old CRT monitor ). Problem is i have crackling / static audio humming in the background of my video audio, picture displays fine though. I've seen suggestions for updating the audio drivers of the pi but am not sure how to do this with LibreELEC installed. Would i need to boot linux off of a flash drive to install the drivers that way or is there an easier way to get the updated audio drivers? Brand new to the pi so am kind of lost.

Where did you ascertain that there are updated drivers, these issues should of been resolved a long time ago.

Maybe you have an issue with your AV Cable ?
Model-B-Plus-Audio-Video-Jack-Diagram.png
Model-B-Plus-Audio-Video-Jack-Diagram.png (22.68 KiB) Viewed 208 times

Does this happen when you are running alternative Operating Systems ?

https://kodi.wiki/view/HOW-TO:Install_K ... spberry_Pi
Adieu

LTolledo
Posts: 736
Joined: Sat Mar 17, 2018 7:29 am

Re: Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 9:17 am

kas03 wrote: Problem is i have crackling / static audio humming in the background of my video audio,
One possible cause, bad contacts on the audio jack of the old CRT monitor. As it is old, it might have some corrosion. You can clean it up by spraying contact cleaner (just make sure you turn off the power first) and plugging and unplugging the audio plug several times.

If that doesn't solve it then your setup probably suffers from ground loop "syndrome"
to remedy that (as I have done as well on 2 of my setups) is to insert a Ground Loop Isolator between the RPi and the CRT monitor

something similar to (but not exactly like) this:
https://www.amazon.com/Mpow-Ground-Isol ... B019393MV2
"Don't come to me with 'issues' for I don't know how to deal with those
Come to me with 'problems' and I'll help you find solutions"

Some people be like:
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kas03
Posts: 4
Joined: Mon Aug 20, 2018 12:29 am

Re: Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 10:47 pm

LTolledo wrote:
kas03 wrote: Problem is i have crackling / static audio humming in the background of my video audio,
One possible cause, bad contacts on the audio jack of the old CRT monitor. As it is old, it might have some corrosion. You can clean it up by spraying contact cleaner (just make sure you turn off the power first) and plugging and unplugging the audio plug several times.

If that doesn't solve it then your setup probably suffers from ground loop "syndrome"
to remedy that (as I have done as well on 2 of my setups) is to insert a Ground Loop Isolator between the RPi and the CRT monitor

something similar to (but not exactly like) this:
https://www.amazon.com/Mpow-Ground-Isol ... B019393MV2
I have used the same crt inputs for my dvd player and game systems, have no problem with the audio there. I'll try your second suggestion

kas03
Posts: 4
Joined: Mon Aug 20, 2018 12:29 am

Re: Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 10:49 pm

fruitoftheloom wrote:
Mon Aug 20, 2018 7:15 am
kas03 wrote:
Mon Aug 20, 2018 12:36 am
So I installed LibreELEC on my Raspberry pi 3 and am using the 3.5 jack for audio / video ( using an old CRT monitor ). Problem is i have crackling / static audio humming in the background of my video audio, picture displays fine though. I've seen suggestions for updating the audio drivers of the pi but am not sure how to do this with LibreELEC installed. Would i need to boot linux off of a flash drive to install the drivers that way or is there an easier way to get the updated audio drivers? Brand new to the pi so am kind of lost.

Where did you ascertain that there are updated drivers, these issues should of been resolved a long time ago.

Maybe you have an issue with your AV Cable ?

Model-B-Plus-Audio-Video-Jack-Diagram.png


Does this happen when you are running alternative Operating Systems ?

https://kodi.wiki/view/HOW-TO:Install_K ... spberry_Pi
I did some research and it seems a lot of people are having this static issue with the 3.5mm jack and a lot of people said driver updates fixed their issue, i mean it could be the av cable that's the problem. I've tested the crt input with my other devices so it shouldn't be that since the audio works flawlessly

kas03
Posts: 4
Joined: Mon Aug 20, 2018 12:29 am

Re: Updating audio drivers for 3.5 jack

Mon Aug 20, 2018 10:50 pm

ghans wrote:
Mon Aug 20, 2018 4:39 am
The audio driver on the Pi has been improved several times over the years. Some of the improvements are actually inside the firmware (start.elf) instead of the Linux kernel.

Updating the firmware (and the Linux kernel) is usally done with the "apt-get" command nowadays. Sadly LibreELEC is notorious for not supporting the "apt-get" mechanism. You can try replacing start.elf (copy-paste works) with its counterpart from here: https://github.com/raspberrypi/firmware.

This copy-paste can also be done from Windows ! (Do not take that for granted. Windows goes great lengths to ignore that Linux exists and to remian subtly or staunchly incompatible.)
Especially any indication that your SD card has been shrunk to a few megabytes is nonsense,
Linux will show you that all remaining space has been properly allocated in a Linux format called "ext4" which Windows tends to ignore.

ghans
Oh nice! Wasn't aware you could copy and paste directly onto the device. I'll try it out and see if there's any luck

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HawaiianPi
Posts: 2899
Joined: Mon Apr 08, 2013 4:53 am
Location: Aloha, Oregon USA

Re: Updating audio drivers for 3.5 jack

Tue Aug 21, 2018 2:12 am

Do you have

Code: Select all

audio_pwm_mode=2
in your config.txt? That is supposed to enable higher quality audio in Raspbian (don't know if it works in LibreELEC).
My mind is like a browser. 27 tabs are open, 9 aren't responding,
lots of pop-ups...and where is that annoying music coming from?

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