A different approach is to buy a preamp which includes a DAC. This way you'll have a fully functional preamp with multiple inputs plus an onboard DAC unit to play back computer audio or a music server.
The Peachtree Audio novaPre is widely recommended around the forums...
http://www.enjoythemusic.com/magazine/equipment/0613/peachtree_audio_novapre_dac.htm
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Sorry, this Peachtree has been discontinued. But I still believe that a full function preamp/DAC is the way to go.
Something to keep in mind when adding a preamp to your system is that the gain and impedance specs will need to match your amp.
If this http://www.butleraudio.com/tdb2250.php is the Butler TDB 2250 amp you own, then there would be no problem matching just about any preamp to it.
The Peachtree Audio novaPre is widely recommended around the forums...
http://www.enjoythemusic.com/magazine/equipment/0613/peachtree_audio_novapre_dac.htm
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Sorry, this Peachtree has been discontinued. But I still believe that a full function preamp/DAC is the way to go.
Something to keep in mind when adding a preamp to your system is that the gain and impedance specs will need to match your amp.
If this http://www.butleraudio.com/tdb2250.php is the Butler TDB 2250 amp you own, then there would be no problem matching just about any preamp to it.