Changing the TV System from NTSC to PAL doesn't affect the other emulators, so you can just leave your settings on PAL and everything will run fine.
For those who don't know, NTSC and PAL settings refer to North American and European TV refresh rates, so game consoles had to be tweaked to work correctly in different regions.
For whatever reason, all emulators can detect and adjust to NTSC or PAL aside from the SNES and GBA emulators, which have to be manually set to PAL or they lag.