Providing the bi-amplified power for DUP's Whispers are no less than four Van-Alstine-modified, fan-cooled Hafler P-500s and DH-500s, each bridged for mono operation. These are capable of delivering a total of 4200W to the Whispers via 12-gauge cable hung beneath the floor. Carl's main signal source is a Philips '963 SACD player, seen here above the Haflers that are used to drive the speakers' mid-treble sections.