I tried to use a standard stereo cable with ppjoy. I was unable to calibrate the joystick controls, as the axis' feedback was giving spastic results. I could almost get the rudder control to work, But that was about it.
I think that maybe the trainer cable has a switchover circuit, resister, or capacitor of some kind. Giving the output to the computer a clearer signal that can be used to function as an input control device.
I'm going to buy the training cable and give it a try. I'll keep you guys posted....