That is because the launch config is wrong for the 750. Check the lyra2v2 file and adjust the TPB and the intensity.
else if (strstr(props.name, "750"))
{
intensity = 256 * 256 * 5;
tpb = 7;
}
As far as I understand I can change intensity with - i parameter without recompile. But it doesn't help, I tried.
What is tpb? Can I change it without recompile?