CrossRoads:
In Reply #15, you have the resistors shorted out - all 5 contacts in a row like that are the same connection.
The resistor needs to connect to 2 rows, such as 40 & 43, 55 & 58.Where are the two 100K resistors per channel? Those are needed to set the 2.5V level after the signal goes thru the cap.
104 is a 0.1uF cap, you may lose some signal there, a larger value cap may be needed.
I WAS using a capacitor but multiple examples with the 3 pronged jacks didn't use capacitors.
With prior projects I did that so the signal(s) going from analog(s) can go through the resistor then through the wiring over the bridge to the channel(s). Or am I wrong here?