The long awaited upgrade to dual stages happened.  Self noise went from -79 to -53db so pow(2, (26 / 6)) = 18x rise in noise floor.   What motivated it were wifi pops every 2 minutes in the ADC.  They only happen in the AUX channel.  Maybe the analog side should all run on a separate battery, as was done 7 years ago.  

The 1st stage has a 1.9x gain because of the 6.8k's in the phantom power, so it achieves a total of 194x.  The single stage had 14x.  The theoretical increase should be 6 * sqrt(194/14) = 22db, so it either added another 4db of noise or the single stage was less efficient.