DACs that do well without a preamp

Most DAC put out 2V single ended or 4V balanced.  Also check the volts required for full power on the amp.  Some volume control bit strip "bit strip" as volume is reduced.  There are several kinds of volume control, resistors based, light based, auto former, digital, etc. 

I went through this, it sounded like the right thing to do.  It did not work for me.  My volume control bit stripped.  My amp needed 1.25v for full power so I thought I was good to go.  My speakers are quite efficient.  I ended up with a passive preamp.  I have great dynamics and sound.

Soekris dac2541. It uses an internal headphone amp as the line driver amp selectable on the front panel. I'm using it to drive an old Threshold amp through a 10k Ohm pot. Works very well. 

Exogal Comet.  Great straight into an amp (no idea how it sounds with their ion amp)

Yet another big vote for the RME ADI-2. It is super in my big tube mono block amps. There’s no turning back and RME sends regular software upgrades. 
 

Just an unbelievable value. 

I'm currently listening to a Marantz HD-DAC1 using the variable output to a Mcintosh MC2100. The 2100 has left and right output gain levels and once calibrated with the Marantz volume control sounds wonderful.