Author Topic: USB noise - cheap solution!  (Read 51 times)

Ilgrazza

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USB noise - cheap solution!
« on: August 08, 2017, 09:26:37 PM »
Xavier

I love my PreenFM2.

I had a slight issue with ground loop noise when using usb power; this is reduced, but not eliminated when using the 9v PSU.  However, I found a cheap solution by accident - the noise disappears when the Preen is connected to the PC via an old KVM switch (£5 from Ebay).

Xavier

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Re: USB noise - cheap solution!
« Reply #1 on: August 09, 2017, 10:58:49 AM »

Thanks for the info  :)

When you power with a PSU AND plug the USB to a computer, did you remove the JMP2 jumper ?

Removing the JMP2 will prevent using the power from the USB.
If you leave it you have current from both the PSU and the computer coming in the preenfm2 which must be avoided.

Xavier

Ilgrazza

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Re: USB noise - cheap solution!
« Reply #2 on: August 13, 2017, 10:51:41 PM »
Xavier

Thank you, I didn't know that - my Preen was built for me.  I removed the jumper and the noise is fully eliminated.

Keep up the excellent work!