1603, 1602, 1803, 1802 are the models that have given me pause of late...running them with less than very efficiant speakers becomes a chore and soft-clipping occurs....they work fine on the Klipsch where ,indeed, they sound smoother than the Yammie (synergy), but with B&w's, Mirage, and a coupla others they ran outa gas.....the models up from the 2802 seem to have more power...haven't run the 3803 through enough hoops yet to comment....