How important is a preamp for purely digital sources?

Apparently rather important ...
  https://forum.audiogon.com/discussions/simply-amazing-coda-technologies-07x-preamplifier

I haven't used an active preamplifier since 2010, and I don't miss it, figuring that adding unnecessary circuitry to the signal path can only degrade the sound, especially if there's capacitors and op amps. I have a Luminous Audio Axiom 2 (a passive that costs $195). You get to remove  potentiometer from your signal path completely that way: the pot is shunted to ground, and a foil resistor is in the signal path. I found some of the responses amusing; about how people think their expensive preamplifiers add "depth of the soundstage", "clarity", "musicality", and "micro to macro dynamics". The DAC outputs are at the Redbook voltage level, and the signal doesn't need to be boosted any further before it gets fed into a power amplifier. There's usually two op amps in the output stage to convert current to voltage. 

There is another aspect to this entire discussion that has not been touched upon. While a preamp may be technically perfect and not enhance or degrade the sound there are two more links added to the chain with an external preamp that need to be considered. The interconnects. I have yet to find an IC at any price point that does not "color" the sound or add noise. I'm a firm believer in the concept of less (quantity not quality)  is more when it comes to ICs. 

jrapp, a well engineered integrated can solve that problem 

I know that but integrateds were not the subject of this discussion. preamp (s) are. When considering how important a preamp is (subject of discussion) and its effects on digital sources one must not forget the IC part of the equation. Years ago I added a very pricey and highly regarded BAT VK51SE to my then all digital system. I had used a pair of highly rated mid/high-line Audioquest ICs that I had from a prior system. The results were not as expected. The sound lacked warmth and was slightly muddy; that is until I replaced the ICs with Synergistic Resolution Reference Active series IC’s. The difference was astonishing; the expected tube warmth was now there and the muddiness was gone. This experience leads me to wonder if the results that some posters are touting are really the result of the preamp addition of the effects of the additional ICs.