I recently obtained this fixture that uses 4 13w PL bulbs, however the ballasts it came with are extremely loud and seem to heavily overdrive the lamps. The current ballasts are Robertson model SP2, which I will add an image of. Anyone know of quiet ballasts that would properly drive the lamps and that I could obtain at least 4 of? Thanks.
Here is a video of the fixture operating, showing the noise.
https://www.youtube.com/watch?v=MBGkSB_3NkI