i never really looked into how it was done before. but yes, it should make the output for the gensis a little darker, but it would make the output for the tg16 look right. if you use an amp that has the 75 ohm resistors, the opposite would happen. this is assuming that the PAC is just a tg16 consoles shoved inside of it as i have never really looked into this before.
you could maybe rig up some sort of switch for the output resistors to swap between different ones.