Pin 2,3,4,5,6 and 7of all three op amp ICs are soldered together. Pin1 and 8 of the each ad844 are bent outwards, isolated from the stack. Then, I soldered just one of the AD844 ic pin 1 and 8 to each leg of the 25k trimmer. Centre pin of the trimmer is soldered to the pin 7 of the stack. Trims down to almost perfect 0dc when I set my meter range to 300mV and stayed this way even after a few hours of playing. Hence I didn't install any output caps.very practical
could you please tell where did you connect trimmer to ad844 to null DC offset
Important, remove the civ and Riv on the board. Install civ and Riv between pin 5 and 3 (ground) instead. i used2.5k ad 470pf.