John, this comes down to elementary issues of logic and of making fair comparisons. If a certain headroom must be allowed for peaks, then use the same yardstick (or metre stick if you will) for the digital microphone as for the chain consisting of analog microphone + preamp + A/D converter. It is misleading to compare only the worst-case analog microphone / preamp / converter arrangements with only the best-case digital microphone arrangements, e.g. by setting the digital microphone's gain for the particular SPL of the event which one is recording, while pretending that similar adjustments somehow cannot be made in a recording with analog microphones.
Say a digital microphone is designed so that full-scale digital output occurs at the onset of audible distortion in its analog first stage (e.g. somewhat above 130 dB SPL perhaps). If one never adjusts that microphone's gain via its interface/controller, its signals will probably fail to use the uppermost 15 or even 20 dB in many of the recordings that one makes with it. Thus one would prefer to increase the gain of the digital microphone somewhat, via its interface/controller. But doing so has exactly the same effects on dynamic range as raising the gain of the analog mike preamp or the input to an outboard A/D controller. Digital gain is not noise-free, nor does it magically evade headroom limits.
--best regards
An AES42 digital mic. has very little analogue in it at all - basically the capsule and an fet and not much else. This is then fed directly into the DAC.
There is no need to adjust the gain at all as it it digital gain and will not affect the quality; though I do adjust the gain as it makes monitoring easier.
But, every bit of analogue circuitry adds its own little bit of noise and the more there is in the analogue path the more noise there is - OK, on a good system this can be very small, but it's still there.
I am not saying that digital mics are perfect and analogue mics are rubbish - there is room for both and will be for many years.
But digital microphones have great advantages and the more I use them the more I like them.
I have been using AES42 digital microphones in anger for 5 years now, so I am speaking as someone who uses them, has read up on them, had long discussions with the designers of them (Neumann, Schoeps, Sennheiser and Gefell) and written papers on them (and before my papers were published they were sent to Schoeps, Neumann, Sennheiser and Gefell for review so they could make comments/corrections before I presented them).
People tend to forget all the little bits in the analogue chain that slowly decrease the specs of an analogue mic. that does not happen with an AES42 mic.
And, yes, I know it was you who translated the White Paper that has been mentioned previously - it's a good paper, though I don't agree with all that is said in it.