Picked up some decent bookshelf speakers and I would like to hook them up to my Dell Dimension 5150 Desktop. Soooo .... need an amp. Does not have to have a DAC but if if does, swell. Not looking for anything great, just adequate. Does anything exist that's decent for $100 or less? Or is...

I recently discovered Tom Waits and I'm loving his music. I am wondering... is there a female singer with the same "vibe"? Not looking for the gravelly voice, more the music and subject matter.