This is most likely a schoolboy error.
I've rigged up a little audio device that uses a Raspberry Pi and I2S DAC to feed into a TPA3116, but I'm getting awful digital noise through the amp output whenever the Raspberry Pi blinks an LED! The 19.5v supply is from a laptop switching PSU.
However, if I power the Pi/DAC with a battery power pack, everything sounds fine.
Have I wired this up wrong, or is the KIS-3R33S step-down board defective.
Thanks in advance!
I've rigged up a little audio device that uses a Raspberry Pi and I2S DAC to feed into a TPA3116, but I'm getting awful digital noise through the amp output whenever the Raspberry Pi blinks an LED! The 19.5v supply is from a laptop switching PSU.
However, if I power the Pi/DAC with a battery power pack, everything sounds fine.
Have I wired this up wrong, or is the KIS-3R33S step-down board defective.
An externally hosted image should be here but it was not working when we last tested it.
Thanks in advance!
Get a GLI.
http://www.amazon.co.uk/201-087UK-J...59790409&sr=8-5&keywords=ground+loop+isolator
...Or one with whatever connections you need, be it RCA phono or 3.5mm.
Though there are proper isolated DC/DC chips out there, I haven't seen a breakout board - such as you can find for the LM2596 etc.
J.
http://www.amazon.co.uk/201-087UK-J...59790409&sr=8-5&keywords=ground+loop+isolator
...Or one with whatever connections you need, be it RCA phono or 3.5mm.
Though there are proper isolated DC/DC chips out there, I haven't seen a breakout board - such as you can find for the LM2596 etc.
J.
How about grounding the 0V of the PSU?
Currently, there is no ground.
Also check what gains you have. How much signal gives full output and is it simply a case of reducing the gain on the amp by turning it's pot down?
Currently, there is no ground.
Also check what gains you have. How much signal gives full output and is it simply a case of reducing the gain on the amp by turning it's pot down?
What can I ground it to?
I'm using a digital volume control in the pi software. So the gain is 26db i think.
Thanks!
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Top pin on UK plug.
I would check gains though. If full volume on your pi clips the amp, that could be your problem. Turn volume down on your amp PCB.
I had similar problem with my old netbook driving 3116 on laptop PSU. Too much gain and hissy noise.
I would check gains though. If full volume on your pi clips the amp, that could be your problem. Turn volume down on your amp PCB.
I had similar problem with my old netbook driving 3116 on laptop PSU. Too much gain and hissy noise.
Does this look familiar?
http://www.diyaudio.com/forums/powe...s-class-d-amp-how-power-them.html#post4636641
Not a Rpi but a CC Audio. The linked GLI works perfectly. I was getting all manner of weird squirrelly noises previously.
J.
http://www.diyaudio.com/forums/powe...s-class-d-amp-how-power-them.html#post4636641
Not a Rpi but a CC Audio. The linked GLI works perfectly. I was getting all manner of weird squirrelly noises previously.
J.
Thanks. I'll order an isolated DC-DC converter and try that. I don't like the idea of putting a ground-loop isolator in the audio signal path.
Yep, that looks quite nice. 🙂
http://www.amazon.co.uk/Yeeco-DC10-24V-Isolated-Regulator-Smartphone/dp/B015E4835U
^^^ One on Amazon UK....
http://www.amazon.co.uk/Yeeco-DC10-24V-Isolated-Regulator-Smartphone/dp/B015E4835U
^^^ One on Amazon UK....
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