Teajay is correct. The X-250 is one of the best amps for the used prices (since the .5 was developed, the X-250 prices have dropped even more) You can buy a used X-250 and resell it for what you bought it for. It works great with tube and SS preamps, has deep, dynamic powerful bass, the mids are as good as SS gets. Good details and soundstage.
Happy Listening.
Happy Listening.