This is a go to mixer. It's a work horse. I did open it up and check each volume knob and sweepable EQ / Aux potentiometers. As far as interoperability with powered speakers or external FX units, this mixer wins. That's why I have it. I also have numero's accommodating FX (effects) processors for this mixer.
Allen and Heath WZ 16:2 DX Sound Board
$250.00Price
I used this mixer and many others (same model) and have never been let down. This unit has been cleaned and tested, each knob and each connection. Thanks for looking, text, call or e-mail. :)