Top critical review
Non-Returnable and Low Quality
Reviewed in the United States on March 3, 2017
Received with defective wall adapter that buzzed loudly as soon as it was plugged in to an outlet--whether it was connected to the preamp or not, across multiple outlets, surge protectors, etc.
Despite there being no information to this effect anywhere on the product page, this item is inexplicably classified as "Non-Returnable." Take a look at the 100 or so 1-2 star reviews to see how many people received defective units (like me) for which there is zero official recourse. Fortunately, Amazon being what it is, a friendly customer service associate may be able to help you out, but I would not advise rolling the dice on this one.
Bought a ART Pro Audio DJPRE II instead and it sounds so so much better and the wall adapter is silent, like a wall adapter should be.