http://www.dansprojects.com/GCDual_Jumpers.html
and noticed this:-
I'm guessing this means the GCDual has TTL level CSYNC as standard, not 75ohm?With RGBS you must use a cable that has an attenuation reistor.
Most CSYNC cables have this reistor already in place. But if you plan to use a composite video cable for sync you must either have an attenuation resistor in the cable or you can make a simple modification to the GCDUAL.
Replace R3 with a resistor between 430-570 Ohms on the main PCB and this will force attenuated sync out
Rather than having to remove a surface mount resistor from the mainboard would it not be possible to have a jumper to select between TTL or 75ohm CSYNC output?
Also, looking at the jumper pads I just wondered if you ever considered a jumper layout like this:-
It just seems more straight forward to have each corner correspond to one of the four MULTI OUT pins.