"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.
