it takes a heck of a DAC to have an analog section capable of robust drive and dynamics that a good preamp brings to the table-
Just about any good dac these days has an output stage equal to or even better than preamps especially tube preamps.
And you don't need anymore gain, we have more than enough in today's sources, use all the gain the source has, don't shunt it to ground, then make it back up again along with more noise and distortion added by a preamps gain stage.
Cheers George