Tube Audio Design (Paul Grzybek) Tadac dac question


Does anyone out there know the DC voltage requirement for the late Paul Grzybek's Tadac tube dac? I own one and want to add a linear power suppy. 
pmboyd
It's the prototype. Ugly as sin but sweet sound. The same except it uses an outboard power supply.
Most wall warts are marked with their voltage output and whether they output AC or DC, but if not it could be easily measured with a basic meter.