Vox Cambridge 50 Lamp combo amplifier for electric guitar. A combo amplifier combines, as its name suggests, speaker and amplifier in one device and all you need to do is connect it to the power. The characteristic of being lamp means that it operates with tubes, commonly known as bulbs, so it has a warmer and more natural sound. You can use it for practice at home as well as for rehearsal/recording in a studio or live performances. In this case, it has a 1 x 12" speaker and has a power of 50W.