Connecting a 5V fan (ADDA, AD0405DB-G70, brushless) to J3 causes some audible noise on the 5V rail (I am not talking about the mechanical air flow noise). It is a 10mV pp ripple somewhere in the mid audio band around 0.5-2.5kHz. Did anybody have the same issue and does know an easy solution for that? I tried several condensators in parallel to the fan, but so far it didn't help (no change at all). Interestingly, I can barely hear it over the PA, but it's very annoying over the pre headphones dir