are these things i experienced today "normal" ?!:

1. turning the volume in both directions makes some crackling noise, not "very" loud but def. noticeable

2. both pres turned all the way up to 60.....noise next to hum

guess the hum in that case is perfectly normal, BUT, i think it starts at about 40db(not sure now...there´s another disturbing noise, it´s not my fridge or anything else around im sure ;-)
aaaand: that noise is slightly louder on channel 2 than on channel 1

both problems, 1 and 2 occur always- with mics either plugged or uplugged.

did anybody have same experiences or is anybody willing to simply turn the computer on, put headphones on, crank the volumes on both channels up and listen for a second?

do you think the unit might be broken or am i simply facing one of the downsides of technology/electricity