XPS 15 L502x firewire connectivity through thunderbolt

Hello

I have the XPS 15 L502x and for a long time I have been searching for a way to connect a firewire sound card. I know it can't be done through usb. I just learned about the thunderbolt protocol used in some mini displayport devices the last couple of years. There is an adaptor to convert from firewire to thunderbolt. Does anyone know if the mini displayport on this particular model is compatible with thunderbolt? Please let me know, it could save me more than $500.

Thanks in advance

Thanos