dear all,
i’ve been struggling with this for quite a while and it appears to be back! heavy buzzing and humming on the ER-301 and my monome teletype.
i thought i had it solved for the grid by powering it externally (which i currently am) – but i must have mistaken. the preamps are quite cranked up in the video, but even without there’s audible noise.
i’m pretty clueless when it comes to power-issues. running my rack off a trogotronic m15. any idea what i could do to pin the problem down? it’s obviously only the mentioned modules and it definitely relates to how many LEDs / display activity is going on.
thanks! 
ps: posting this in a thread on the OD forum, too…