DACs that do well without a preamp

Sonnet Morpheus at around $2K used or Metrum Jade at even less should both sound pretty good.

VC is implemented by changing the reference voltage so no bits lost.

@itsjustme 

As an over-simplification: the only DACs to truly do volume control well are based on 32-bit, sigma-delta DAC chips

Have you heard or considered the Cees Ruijtenberg (Metrum then Sonnet) DACs that control volume, i.e., change the output voltage, by changing its reference voltage?

I find the "a preamp makes it sound so much better" a little confusing. 

Many (but not all) who have listened to the comparison between DAC-direct to amplifiers vs. using a good quality active preamp, and also the comparison between using a passive volume control vs. a good quality active preamp, report that having the preamp sounds better.  That has also been my opinion after multiple comparisons using passive volume controls and also using DACs that control the volume internally.  Although there are obviously subjective preferences at work, as in all of this hobby, IMO, the active circuitry in the preamp (even a unity gain buffer) helps control impedances and interconnect effects, and also mitigates potential demands on the source power supply.  Below are a few observations posted previously here:

DACs are significantly more sensitive to power supply changes and noises than preamps. When an output stage struggles to drive a complex load, it is the power supply feeding its output stage that sees these changes. If this occurs in a preamp, it has little effect. But that same situation, when applied to a DAC, has very different results indeed. Small changes in power supplies have big impacts on sound quality–especially jitter. - Paul McGowan

in support of the previous quote: 

Now of course such a line section could be built into a DAC- but then you have the issue of if you ever want to improve the DAC or the line section, you have to replace both (and its often not a good idea to have a DAC and line section run off of the same power supply). DACs are notorious for going out of date; this is a very real issue. - Ralph Karsten

and

I would expect other factors to be at play in many cases, depending on the specific equipment. Such as better sonics from the source component when its volume control is set at max than when it is attenuating the signal; differences in ground loop effects (which can affect low level high frequency noise and consequently “background blackness,” in addition to potentially causing hum), differences in impedance relationships; differences in sensitivity to cable effects, especially if a long run to the power amp(s) is necessary; - almarg

and finally, relative to passive vs. active preamps:

The reason an active line section can sound better than a passive has a lot to do with interconnect cables. Passive controls have poor output impedance- usually quite high, which allows the interconnect cable to do its worst mathematically speaking. - Ralph Karsten