With a 70dB S/N ratio and 0.05% maximum distortion, the new TC-450 introduces the first battery-powered model to our lineup. One nine volt battery will run this low current-draw preamp for many, many hours. Or you can use it with the optional power adaptor, just like our other models. Either way, this preamp (both lightest and smallest of any we sell) adds a new measure of flexibility for those of you recording or listening to your albums on the go. The same sturdy metal construction used in our other models provides excellent shielding, noise rejection and durability. This listing includes our optional 1A SMPS audiophile grade AC adaptor.