Nice unit with fatal flaw; can't remove dead batteries!
Electrically, this dual preamp does exactly what it should. The pres are quiet, the construction quality is robust (with one glaring exception- more on that in a minute) and the pots are static-free. When running the unit on an external power adapter (not included) or via USB, you'll probably be a happy camper.
HOWEVER. If you need to run it on a 9V battery for field use, you're out of luck. The battery "compartment" is, believe it or not, a taped-together CARDBOARD sleeve which seems to be intended to keep the battery case from shorting out the nearby, and fully exposed, electronics. The battery is held in place by friction alone; there are no walls whatsoever on the battery 'compartment.' Unfortunately (to put it mildly) there is absolutely no way to remove a dead battery from the unit! That's right, it's stuck in there forever. There's no room for needle-nosed pliers to get a grip, there's no possible way to get your fingernails around the battery, there's no little red 'battery removal' ribbon like there used to be on old-fashioned electronics... and even if there were, the cardboard sleeve fits in the opening so tightly that I'm not sure the battery could be removed before the ribbon broke.
Unless you have the foresight to stuff a little gremlin inside the unit who can shove dead batteries out for you, (which I didn't,) you're well and truly out of luck when it comes time to change the battery.
ART really blew it on the battery 'compartment' design. The unit is otherwise a dandy, affordable preamp- but how they let this flaw get past them is anyone's guess. Disappointing, to say the very least.