I’m keen to know where the grounds should be linked. I’m seeing the M card
ground is 0.3 ohm with respect to the logic power ground, but around 2k to the
+/-15V ground. I’m guessing that shouldn’t be the case?
I
remember that in the case i mentioned, some of the voltages I measured would
change unexpectedly when I played up and down the keyboard, thus giving me the
clue that the analog and digital systems had become "floating" relative to each
other.
