The Mezmerize is a direct coupled preamp (no coupling caps) based on Nelson Pass's B1 Buffer. It boasts symmetrical Salas shunt voltage regulators that use LED strings for very accurate voltage reference. Included in the board are provisions for up to 6 relays for input signal switching and an output relay for delayed start-up muting. Being based on a B1 Buffer, Voltage Gain should be close to 1.
Please visit the Mezmerize Helpdesk Thread to ask any questions and get a definitive list of related resources on diyAudio.