I have Litronics. The left side low beam is out but the high beams work fine.

Are there two separate bulbs, ie do I have a burned out light bulb? Or does the fact that the high beams work mean that it's more likely to be a connection problem?

I have a 2001 stock Boxster and the Litronics came from the factory.

 

Yes, two bulbs. The low beam is Xenon and the high beam is Halogen. When you turn the high beams on both are used - the Xenon beam is rotated up to add to the Halogen.