i just bought 8 phantom 1k watt ballasts. There working great so far, they have a soft start on them which is genius, you don't damage bulbs or components from excessive re-starts. Each ballast ran at 220v. takes 4.2amps electric. Extra quiet !! I mean , these things barely make a sound. You can mount these ballast's vertical or horizontal. No fans on these ballasts so dirt/dust can't get in the unit,Plus the fans are noisy and break down on you anyways.
Overall I am pleased with the purchase, These ballasts are quiet,effective and reasonably priced. Nothing bad to say about these Ballasts !