USING AFTERMARKET PLATE AMP FOR Hi

Good morning, my name is Calvin.  I have a Velodyne HGS15BG subwoofer that I purchased from US AudioMart couple weeks ago.  The sub is in immaculate condition.  I got it for $190 because it was missing the oem plate amplifier.  The Velodyne hgs series subs all came with a high gain servo 1250rms 3000w peak amp. I'm been trying to find the oem plate amplifier for the hgs15bg but have had no success!!  Does anyone know of a distributor that sells this plate amp for the Velodyne hgs-15???