IMHO the AD843 is better sounding overall than the AD-8610/20 But the 843 draws 13 Ma and the 8610 3.5 at the most and typicaly 2.7Ma. in addition the 8610 has some sonic advantages over the 843. The AD-843 has been my fav opamp for over a decade but it is getting old and is built upon the Analog devices CB process like the Dual AD-823. the CB process is a juntion isolated process and is not as good as the Dielectric isolation process the 8610/20 are built upon. Also the 843 will only swing to within about 4 volts of the Rails while the AD-8610/20 to with in 1.2 Volts Hope this helps.