Can a DAC sort out a flat\cold amp?

The room will be a mess, but I don't think the speakers in that location nor even the reflective surface are going to result in too little bass. I would expect boomy bass from the near corner placement.

Something is broken. One of the speaker polarities wrong, bad amp, etc. Replacing the speaker cables, using Roon (except for equalizer which you can do much cheaper), interconnects, DAC, and a bunch of other things is not going to make any difference. Find out what is broken and fix it.

Buy a microphone and learn how to measure your setup, then you will not need to guess.

+1 Elliotbnewcombjr

A gross lack of bass is NOT characteristic of that amp or any properly functioning modern HiFi SS amp. Other than speakers wired with incorrect polarity (a definite possibility), an impedance mismatch (unlikely) or your seat is smack dab in a null created by room acoustics, I’m hard pressed to come up with another rationale for what you describe. A Schiit Loki may be your best bet if the other proposed solutions don’t provide an answer. 

@orenm145 I concur with many others that have already stated that the amp is not the problem

In the interest of problem isolation, if you have not already done so, may I suggest you simply your build for a moment and validate the source of the problem

Take the PC and network out of the equation

What happens when you play the tuner, are you happy with the bass?

If so move up the food chain and connect an external CD player to the Yamaha and test

Those two tests should confirm if the amp is part of the problem

Best of luck

"A gross lack of bass is NOT characteristic of that amp or any properly functioning modern HiFi SS amp..."

With due respect, I disagree with this statement here.  The disparity of treble, midrange and bass sound signatures among all types of amp. could be highly significant.  This applies to Yamaha as1200 without exception.  Listening to several reviewers such as Tarun (a british audiophile) and Andrew (Robinson), they both point out as1200's bass is nimble, textured but not as weighty/full as compared to several noteworthy competitors.  It has been well-known the Yamaha amplifiers were relatively leaner sounding in the bass region and that was why I start up my 2-channel hi-fi system with the Harmon Kardon Integrated amplifier 25 years ago.  Don't get me wrong, the higher end Yamaha amplifier like this does shine in its high-end frequency clarity which produces very transparent / detailed treble. But as a compromise, this clarity also extends into its midrange which also produces leaner sounding compared to its peers.

Given that sound signatures of the amplifier, it is difficult for a DAC to mitigate its leaner performance in midrange or bass.  While noticeable refinement can be expected, a complete make-over that changes the sound signatures of a amplifier is less likely.  That is why I was suggesting a cost-effective solution with Hegel Integrated amp.  Don't take my words for it.  I am just translating my previous experience to the OP so he could make more informative decision.