Be sure to check out my thread "I (heart) Thomas Duplex."

You can find instructions there for a complete redo of the filter packs. It's easy to add extra diffusion to cut down on the light dramatically. I do have one side masked with black foam core for when I am printing fiber finish prints. For quick RC proof work I usually have it wide open.

Mine has a tiny hum that is easily masked with not very loud music.

Love it!