Can you post a pic of this weapon. I have an armstech and made the redoubt version of http://www.torhead.com/schematic/byekC9H/grand-vanquishers-electrostaff . It has the same amount of damage as the Techstaff that you get from the Lights Out quest just higher stats. I have RE'd close to 40 of these staves and I can not get the purple version to proc. I have yet to see one and I am curious if it is bugged, there is no recipe, or if I am just having really bad luck.
And on a sidenote, why would the armstech level 50 techstaff recipe be called Grand Vanquishers ELECTROSTAFF