Hi, I create backing tracks at home using various samplers, sound modules, drum modules etc. and I've noticed every now and again I get a barely audible, but nevertheless distracting high pitched click, similar to a closed, tight hihat strike. As far as I can make out I have all the gains set up correctly. I intend to start using the mixer live but don't want to if it's going to continue doing it, although listening through a pair of very good headphones is different to listening through a big PA system out front.
My mixer is the Presonus Studiolive 16.4.2 and I like it a lot, but up until now I've been using good old analogue without any problems - they're just getting old now.