Norns: noises with grid & wifi

My norns is producing some faint pulsating noise when I use the wifi nub and grid simultaneously and have them plugged in into specific usb slots. Can anyone try to repro this?

Steps to reproduce:

  • listening via headphones
  • norns not connected to usb power
  • awake script, remove all notes for silence
  • looking onto norns, leftmost usb is #1, rightmost is #4.
  • grid connected to #3, wifi to #4: noise is audible (switch on compressor to make it more audible)
  • grid connected to #4, wifi to #3: noise is audible
  • grid connected to #1, wifi to #2: noise is audible
  • grid connected to #2, wifi to #1: noise is audible
  • grid connected to #1, wifi to #4: no noise
  • no grid connected, wifi to #1: no noise
  • grid connected to #3, no wifi nub connected: no noise

No noise with any of these combinations for me.

Thanks. Do I need to be worried?

Anybody else want to try this?

Just tested and no noise for me either. What grid are you using? Is it powered by norns or externally? Not sure if it’s important, but I was using the latest gen grid, and powering it via offworld.

I should have mentioned this in my steps to reproduce:
It’s a November 2015 grid, and it is powered by norns directly.

@x2mirko & @Justmat: Do you hear noises if your power your grid directly from norns?

have you checked your grid for tantalum vs. ceramic caps? i don’t recall the exact year that the the ceramics were mistakenly used by our PCB assembler.

I powered my grid directly from norns when I was testing, so no.

Looks like the caps are alright – I already got the tantalums. Any further hints on what could produce this noise? Can you repro it?

And of course the steps to repro should also mention that you have to set up norns wifi as hotspot, sorry!

That soldering job looks pretty bad! Did you receive the grid that way?

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those are the correct caps.

and the soldering is fine. it’s just a little heavy. like i said the assembly house put the wrong caps on so these were hand-replaced.

in short: i’m having a difficult time coming up with ideas why there would be noise on some ports and not others. it may also be something with solders on the USB ports, or robustness of the USB ports themselves (though these are expensive molex ports).

i’ll keep looking into it and thinking on it, but best you just note what works and stick with that. i wouldn’t worry that there’s some deeper problem at hand. and of course i’ll post when i have a complete fix.

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Thanks Brian – I’ll stick to your advice to not worry about it :slight_smile:

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