In this particular case, given the relatively low output impedance of the DAC2 series, and given the 32 bit processing that is utilized in the digital part of its "hybrid gain control" mechanism, and provided that none of your sources are phono cartridge/phono stage combinations providing particularly low output (gain does not appear to be specified for the analog inputs of those DAC2 models which provide analog inputs), you don't "need" a preamp, at least from a technical standpoint.
As many of the others have indicated, though, whether or not you would find incorporating a preamp in the signal path to be sonically preferable is not predictable with any certainty, as it is system dependent, listener dependent, and perhaps even recording dependent. It might even be dependent (in unpredictable ways) on whether or not the power amp you settle on would be driven by the DAC2's balanced or unbalanced outputs.
Personally, my instinct is to place the burden of proof on adding anything to the signal path that might not be necessary. And my suspicion is that while a high quality active preamp, especially one that is tube-based, would more likely than not enhance the sound quality of your system, obtaining that enhancement to a meaningful degree, and without introducing unwanted side-effects, is likely to cost significantly more than the sub-$2K price you will be paying for the DAC2 itself.
Good luck, however you decide to proceed. Regards,
-- Al
As many of the others have indicated, though, whether or not you would find incorporating a preamp in the signal path to be sonically preferable is not predictable with any certainty, as it is system dependent, listener dependent, and perhaps even recording dependent. It might even be dependent (in unpredictable ways) on whether or not the power amp you settle on would be driven by the DAC2's balanced or unbalanced outputs.
Personally, my instinct is to place the burden of proof on adding anything to the signal path that might not be necessary. And my suspicion is that while a high quality active preamp, especially one that is tube-based, would more likely than not enhance the sound quality of your system, obtaining that enhancement to a meaningful degree, and without introducing unwanted side-effects, is likely to cost significantly more than the sub-$2K price you will be paying for the DAC2 itself.
Good luck, however you decide to proceed. Regards,
-- Al