True...I had to cut a trace on the main board to remove a capacitor from gthe output. This was done at the suggestion of the engineers at presonus. Despite the difference, the AD797 makes the preamp sound much better to me so despite the inherent benefits of the NE5534 (cheap, readily avaiable, plenty of great cicuits to draw from, etc.) there are still better options out there, albeit at a higher price.
I will say this though, the Amek 9098 uses 5532 and 5534 chips and is an excellent preamp (for transparency) and the Focusrite ISA110 is one of my all time favorites ever, and I think that uses 5534s too so at the end of the day it's all in the circuit.
Shane