My Norns is producing a high pitched tone (i am talking about the Norns itself, not the line OUT). The more led i light up, the more the tone volume is high (i tried with EKOMBI patch).
Would externally powering the grid with the usb split trick would fix that thing?
how are you powering the Norns itself? where is the other end of the usb plugged in?
I don’t know if this is relevant but so far my grid does this (high-pitched noise, gets louder with more and brighter LEDs) to some extent no matter what it’s plugged into. it’s so high as to be on the edge of my hearing and never very loud.
I guess it might be that those of us who are older just can’t hear this issue! 
(to be clear - referring to me not you @alanza )
i’m sorry for the trouble.
there may be a slight amount of LED noise if a script is lighting up a lot of LEDs. EKOMBI in general is very over-lit. (i’d suggest redesigning the grid UI for less LED density).
the noise should be reduced if running off the provided USB power supply or similar supply.
you can certainly use an offworld or other USB power splitter, but i’ve never had the need to do this. in general the norns USB supply is pretty robust.
Tried everything, even battery only.
Changing line 429 to g.led(n, i, 2) makes the tone disappear. Fun fact: g.led(n, i, 15) is changing the tone frequency to a new one that bother me a bit less.
So people, be careful with brightness overload (except if you’re working on a singing_flashlight.lua)
I get this a lot with Loom, apart from offworlding the grid is there anything else I can do?