You Do Need power plug adapter while traveling from Bulgaria to Faroe Islands.

Here is Why You Need An Adapter

The outlet and plug type used in Faroe Islands are C, E, F and K and in Bulgaria are C and F. This is how they look like.

Bulgaria

In Bulgaria, outlets of type C and F are in use.

Type C

Type F

Faroe Islands

In Faroe Islands, outlets of type C, E, F and K are in use.

Type C

Type E

Type F

Type K