Horrifically noisy with clicks and pops at any volume over a whisper. Have tried various power options as well as separating those to different electrical outlets.
The use in my case is a pair of speakers tied to both an Amazon Alexa and a Google Chromecast Audio in the basement. this way only one set of speakers are needed. Quality audio is not really that important, streaming music or podcasts throughout the house on the cheap is the intent. Since quality in the basement is not a real concern a little noise is acceptable.
Paired this with a Pyle PFA200 to drive the speakers, this does not provide power and wasn't intended to.
Great idea, poor quality and too expense. Am looking for another mixer option for other locations in and around the house.
UPDATE 2/9/2019 ++++++Adding a star++++++ The company reached out to me and after discussing my issue I tried a variety of options to power the mixer. I found that operating on battery there was NO noise introduced into the audio output. My problem is with any USB power source noise is entering the circuit which is not really the mixer fault. I have run a cable to an entirely different AC outlet a room away which is working well...for my basement. Certainly not sure how this could be mitigated and probably will continue to play with options.