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Noise on audio

Posted: Tue Dec 09, 2014 11:03 am
by smartroad
Hi! I am trying to make a WiFi speaker using Volumino. Currently I have a lot of noise on the sound output and you can also hear beeping when the WiFi dongle is accessing. I know that the built in sound option is not really good for HiFi level sound, if I install say the HiFiBerry DAC should that solve my problems?

I am powering the system via 12V which is directly fed into the amp and then I take off from that and supply a SMPS to get 5V for the RPi and inject it into the 5V pins. Don't know if that could cause any issues as well?

Re: Noise on audio

Posted: Tue Dec 09, 2014 11:10 am
by RaTTuS
wifi will interfere as it is so close
hi-fi berry will be better
hdmi audio will not suffer from wi-fi problems

Re: Noise on audio

Posted: Sun Dec 28, 2014 5:31 pm
by smartroad
So I have tried removing the ground from the audio part of the link as the DSP and amp are run from the same power source (thus linked ground), no joy still have noise :(

The only way I have been able to get rid of the noise is to power the amp and Pi/DSP separately, a 12V supply for Amp and a 5V wall wart for the Pi. But this isn't a practical solution. the problem is obviously that they are sharing the same power supply, and I assume that it is because of some form of feedback via the power pins. The problem is I have no idea on how to isolate the audio from the power supply :(

If anyone has any suggestions I would greatly appreciate them!

Re: Noise on audio

Posted: Sun Dec 28, 2014 6:55 pm
by FM81
The wiring of your ground lines may be wrong! So a part of the raspis current will go over the audio-ground and create the noises.

Possible solutions:
Find out and avoid the "double ground".
Or power the raspi via a fully isolated regulator.

Greetings, FM_81