I have confirmed operation with an adapter that I own. The knobs and buttons seem to be fine, but for some reason, there is variation in the volume of the keys. Searching the web shows cases of this, so it may be a problem with this model. The unit has stickiness, and there are many dirt and scratches. This is a listing for the main unit and original box only, with no accessories. The original box is also heavily soiled. This product is also discontinued by NI. As such, it is being listed as junk. Thank you for your consideration.