500mA @ 9vdc Warmup, 250mA @ 9vdc After Warmup
Center-negative, like most guitar pedals
Vampire Slayer is a no-frills all-tube buffer. It runs a single 12AU7 tube and offers a high input impedance, low output impedance, and wide frequency response. It does an excellent job of adding some extra tube warmth after any solid-state effect, or in the FX loop of a solid state amplifier to get some post-preamp tube warmth before you hit the power amp.