Amplifier to pair with NHT 3.3


I'm the proud owner of a pair of used NHT 3.3s. From what I've read I should be feeding them with something capable of plenty of power, but I've got them running off a small crappy integrated amp (30W) at the moment. Any suggestions for an upgrade? I'm looking in the < $500 range for something used. Thanks in advance.
baldeep
correction to my last. It's 103 Db A-weibhted s/n not 105. I have since gotten an XLS1500 to drive my VR-2 speakers in another room, sounds great.

The Audio magazine world is full of suspect reviews because frankly the high end expensive equipment advertisements pay a large portion of the bills. Even when not so influenced we all tend to have prejudices and illusions and so do reviewers, who often are ignorant of new equipment requirements and proper matching.

Class D type amps appear to be the future for most of us now. They have truly begun to compete with much more expensive to make equipment. They will only get better in the future.

There is a blog started by a young magazine reviewer, Andrew Robinson, who seems to have run into some negative industrial pressure in the end?
Its a good and interesting read. He discovers more about the amps as he goes along and so do others:
http://www.hometheaterequipment.com/mono-stereo-amps-59/crown-audio-xls-drivecore-series-amplifier-official-thread-1319/
I have found that the Crown XLS-1500 will do just as good a job as the XLS-2500 as it too has more than enough clean clear power for The NHT 3.3's at over 400 watts RMS a channel into the average 6 OHM load of these speakers. Since these excellent amps can be found for only about $250 delivered on the second hand or refurbished market I now recommend them over the XLS-2500 due to price.
Well this is embarrassing but I recently got some new hi-end  hearing aidsand decided to A-B compare  XLS amps   with  my old B&K ST-202+ and
although the XLS sounded very good the ST--202+ was a whole level better. I apologist  to anyone I might have misled. The 202+ is rated 200 watts into 8 ohms and 300 into 4 ohms and has a tube like FET output sound