Hello all.
I didn't know where to ask this, but I have an annoying hum issue! I've got an early Pi installed in my van. I bought a Shenzen 5 volt switcher
https://www.amazon.co.uk/gp/product/B00HV4EPG8/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
It supplies my pi and Muse USB dac
https://www.amazon.co.uk/SMO-Conver...&sr=1-2-catcorr&keywords=MUSE+USB+DAC+PCM2704
Well, I got this annoying hum. I've unplugged the rca composite video to lcd display, does nothing, unplugged the lcd display power, does nothing. Got a Lowpass filter on the main 12 volt line and elliminated the alternator whine I had, got de-coupling caps on the audio rca lead. The system is silent until I boot the PI, you can hear the text load, the desktop display, you can hear VLC player being launched. Seems like the noise is beeing fed from the PI through the USB dac!
So, I think I've dealt with the usual Ground Loops and alty whine, what else can I do?
Thanks, Mike
I didn't know where to ask this, but I have an annoying hum issue! I've got an early Pi installed in my van. I bought a Shenzen 5 volt switcher
https://www.amazon.co.uk/gp/product/B00HV4EPG8/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1
It supplies my pi and Muse USB dac
https://www.amazon.co.uk/SMO-Conver...&sr=1-2-catcorr&keywords=MUSE+USB+DAC+PCM2704
Well, I got this annoying hum. I've unplugged the rca composite video to lcd display, does nothing, unplugged the lcd display power, does nothing. Got a Lowpass filter on the main 12 volt line and elliminated the alternator whine I had, got de-coupling caps on the audio rca lead. The system is silent until I boot the PI, you can hear the text load, the desktop display, you can hear VLC player being launched. Seems like the noise is beeing fed from the PI through the USB dac!
So, I think I've dealt with the usual Ground Loops and alty whine, what else can I do?
Thanks, Mike
Are you using an amp?
If so, is there a problem with noise when using headphones plugged directly into the Pi?
Have you tried powering the Pi from a batter that has no connections to the vehicle (completely isolated)?
If so, is there a problem with noise when using headphones plugged directly into the Pi?
Have you tried powering the Pi from a batter that has no connections to the vehicle (completely isolated)?
The car system does not have a 50/60Hz mains supply.
It can't have "hum" in the conventional sense.
What do you mean by "hum"?
It can't have "hum" in the conventional sense.
What do you mean by "hum"?
Bacause the Pi has a lousy output on its headphone socket and the only other way is HDMI!
Okay, maybe the hum is a buzz. But a low frequency one!
Okay, maybe the hum is a buzz. But a low frequency one!
Hi, sorry for late reply. The pi headphone output creates more noise. I installed X screensaver and you can hear all the graphics changing as the screensaver changes patterns. The amp is an LE SON 2 channel cheapy from eBay. It's quiet when I unplug it's audio input.
Thank you
Thank you
What is the resistance from the RCA input shield of the amp to the primary ground of the amp with no RCAs plugged in?
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