Traditionally, a DJ will use two turntables simultaneously and mix between the two. These are connected to a DJ mixer, an amplifier, speakers, and various electronic music equipment such as a microphone and effects units. The DJ mixes the two albums currently in rotation and/or does "scratching" by moving one of the record platters while manipulating the crossfader on the mixer. The result of mixing two records is a unique sound created by the seemingly combined sound of two separate songs into one song. Although there is considerable overlap between the two roles, a DJ is not the same as a record producer of a music track. The development of DJing was also influenced by new turntablism techniques, such as beatmatching, a process facilitated by the introduction of new turntable technologies such as the Technics SL-1200 MK 2, first sold in 1978, which had a precise variable pitch control and a direct drive motor. DJs were often avid record collectors, who would hunt through used record stores for obscure soul records and vintage funk recordings. DJs helped to introduce rare records and new artists to club audiences.