Direct-drive turntables are essential to DJs who scratch and mix music because these turntables do not contain belts that could possibly break or stretch in the way belt-drive turntables can. DJs who mix songs together and seamlessly blend rhythm tracks need to have two turntables of the same model so there is no time between songs while the DJ switches records.
Turntables meant for scratching and mixing require special needles designed to reduce wear on vinyl records. If you are performing in a nightclub or any other type of venue, it is a good idea to have a spare needle with you in case one breaks or becomes damaged.
DJs use specific mixers, often referred to as DJ mixers, to connect their two turntables, CD player or other music sources to an amplifier. DJ mixers are used to control the volume of each turntable, allowing DJs to turn the volume of each turntable up and down and to blend songs together. Professional DJ mixers usually have inputs for two turntables, a CD player and an auxiliary input. Good quality mixers will also have gain controls for each separate input as well as a master volume. DJ mixers must have crossfade volume controls, which allow the DJ to switch between turntable one, turntable two and CD player---or they will not be suitable for professional use. Most DJ mixers feature an equalizer, which can help to blend songs together. Factory-installed equalizers are generally of poor quality---therefore, an external equalizer should be used as well.
Some events that you might DJ will require you to bring your own amplifiers and speakers. When purchasing an amplifier, you need to consider the size of the venue you will be performing at. If you plan on performing at small house parties, you do not need an amplifier with a high output volume. However, if you plan on performing at a variety of different size venues, make sure your amplifier can produce enough volume for the large venues as well. When you purchase speakers to go with an amplifier, make sure that you match the impedance of your speakers with your amplifier. If you do not, you may not get the maximum power out of your amplifier and speakers, or worse, you could do permanent damage to your speaker cones.
Headphones are an essential part of a good DJ setup. Headphones will allow you to hear the nuances of what you are doing when the noise created by the people around is too loud. Closed back headphones that provide good isolation are the only choice for DJ work.