I've followed the DaDa mods to this Quad 44 pre amp but have Oscillation on the output and am needing some hand holding as to narrowing this down to a particular circuit board at first.
As it Oscillates on all inputs I though that I'd pop the old opamps back onto the Radio input card but still oscillation so input cards clear with that logic I think?
This then leads me to the Mother board, where would I probe the signal? I was thinking along the lines of on attached pic,
Points 3 inputs to the CD4066BE from the input cards
Points F and A on IC403 for the output of this board
Which points are the outputs of the IC Switches
Attached Thumbnails