The Mytek literature says, "Mytek Brooklyn DAC is equippped with external 12VDC power supply input. There is some sound quality improvement (particualrly deeper base and better soundstage) when a large external power supply is used. To have an effect the power supply has to be substantailly (5-10 times) larger than the 30W internal power supply. Here are some option which have been used by our customers. Mytek has not yet conducted testing of either of these."