Blackstar Series One 100 Head for electric guitar. The head is essentially the amplifier, but without the speaker to reproduce the sound. It is not necessary to connect the head to a speaker in order for it to work, but in order to practice, you will need to connect headphones or speaker cabinet. A head can be used for practice at home as well as for rehearsal/recording in a studio or live performances. In this case, it has a power of 100W.