neon power supply

hi!
i obtained some 12" blue neon tubes from ebuyer couple of months ago and i have problems connecting them to my computer (PSU overload). Does anyone know the voltage reading on them cos it doesnt say anything, it comes with the power divider thingy (enables connectivity to 2 neons)
i was wondering if anyone has/llink to a schematic co connect the neons to the mains (using a voltage regulated adaptor) and to make them sound activated.....thanks

PM5k

they should just be 12V each. as for the adaptor, i dunno what to suggest