12-03-10: Bombaywalla
OK, I see that I am right & you are also right - after upsampling (marketing verbage used by Wadia is "resolution enhancement") the word length is 24 bits (which is what I wrote) & then, after processing by DigiMaster algo, they chuck the least 2 significant bits & reduce the rez to 21/22 bits (which is what you wrote).
as you saw in the white papers, the wadia has a 22-bit DAC, so the wadia digital preamplifier operates on the 21/22-bit signal. that's why you don't start losing significant bits (from the 16-bit input stream recovered from the cd) until you hit a digital output level of about 65 (out of 100). each step in the digital output level knocks off about 0.5dB, so by the time you get to 65, you are down about 18dB, which effectively reduces the signal by a factor of about 64; i.e. the signal is about 64 times weaker in comparison to the unattenuated digital signal. this, in turn, effectively knocks off the 6 least significant bits from the 21/22-bit signal. thus, by the time you are at 65 on the digital output level, you only have the most significant 15/16 bits remaining in the original 21/22-bit signal and you are at the point where you are starting to lose significant information (since the original signal from the cd was a 16-bit signal).