Shirley wrote in the www.OpenBCI.com forum on November 2020 how to do this: @alwayswearshats to remove C4 (100uF ceramic) and replace it with a >300uF electrolytic capacitor noting to not use an ultra low ESR capacitor as you clarified. -Shirley https://openbci.com/forum/index.php?p=/discussion/2108/measured-shield-regulated-3-3v-supply-has-6v-dip-at-1-second-intervals-with-resonant-ringing