Behringer a500:
http://www.behringer.com/EN/Products/A500.aspx
I've used two of these to power the sub modules of my Zu Definition 2's for the last few years and they've been perfect. Real transformers, about 500 watts into mono, very little heat, great power and control. And pretty sure I got the pair delivered for under $350. Too good to be true, but actually true. I haven't had one thought of replacing them for any reason other than a potential future failure.
http://www.behringer.com/EN/Products/A500.aspx
I've used two of these to power the sub modules of my Zu Definition 2's for the last few years and they've been perfect. Real transformers, about 500 watts into mono, very little heat, great power and control. And pretty sure I got the pair delivered for under $350. Too good to be true, but actually true. I haven't had one thought of replacing them for any reason other than a potential future failure.