Noise on my Drumbrute

[giuntini.leo@gmail.com]

Same noise as shown at this link from another user
https://soundcloud.com/mykhailo-purish/drumbrute-mix-output-noise

My Drumbrute (secondhand) just hiss all the time, constant noise, very low but very audible.
Same from Mix Output or Headphones (both 1/4 or 3,5), enters in my DAW even if Master Volume is turned down.
Is that normal? Hope not