In The Cut: A Composer’s Guide To The Turntables

Two Turntables and a Mixer: A Survey of Mix and Scratch Techniques

The iconic altar of the DJ priesthood has always been two turntables and mixer. Even recent digital mixing technologies that use no vinyl records, or even CDs, usually still feature an interface of two disk surfaces with a mixer in the center. This design, with its anthropomorphic appearance, and resemblance to the symbol of infinity, persists partially because of its familiarity but also because of its ergonomic balance. Right and left hands are given equal opportunity on this platform, focusing on forward and backward movements of the record hand along a circular path. While both hands are occasionally employed simultaneously on the two turntables, and sometimes on the same turntable, a DJ most often keeps one hand engaged with the faders of the mixer—as important a tool as the turntable in the technique of scratching. To understand the unique ways in which turntablists create new sounds, one must first have a basic understanding of the features of both the turntable and the mixer.

Features of the Turntable

The most easily identifiable feature of a turntable is its circular platter, which spins continually beneath the record while the motor is on. The platter rotates the record with it, yet will also continue to spin when the DJ places a hand on the record to stop it. Friction between the record and the platter is reduced by a slipmat that sits on top of the platter, allowing the platter to continue rotating while the record is moved independently. When the record is released by hand, it can quickly resume playing at normal speed as long as the platter is powered by a high-torque, direct drive motor system. A type of vibrato, or a downward pitch bend, can be achieved by dragging the platter—that is, rubbing a finger against the side of the platter as it turns to interfere with its normal rotating speed. This technique is also occasionally used to affect rhythmic alignment when mixing two records.

The Start/Stop button, as one might guess, starts and stops the rotation of the platter by the motor. The brief sliding sounds of starting and stopping the record, usually lasting a fraction of a second, are often used for musical effect in turntablist performance. High-end modern turntables, such as the Vestax PDX-2000, offer nuanced control over the start and brake speeds—allowing long rises and falls, as well as sudden starts and stops. Certain turntable techniques specifically call for the motor to be turned off, using only manual rotation of the platter at varying speeds.

Aside from the two buttons that set the standard playing speed at either 33-1/3 or 45 RPM, the main tool for changing the speed of the platter is the pitch slider. The standard range of variation is +/- 10%. The aforementioned Vestax turntable also has an ultra-pitch slider that can change the speed +/- 50%. The pitch sliders are most often used to adjust tempo when beat-matching records, but also provide a precise means of creating melody from sustained tones on a record. When writing for another DJ, it’s advisable to check with the performer about the interval range of the pitch slider on his or her turntables. A safe range for most turntables would be an augmented 4th, centered on whatever sustained tones are available on a record. A turntable equipped with an ultra-pitch slider can handle smooth pitch shifts within a perfect 12th.

The near-microscopic “needle”, or stylus, rides in the groove of the record and picks up the vibrations encoded in vinyl. A rounded-tip stylus is designed for scratching, with less likelihood of skipping but with some sacrifice in the upper frequencies of the audio signal. A diamond-tip stylus is designed to transmit a higher quality of sound, but will easily skip if used for scratching. The stylus is connected to a cartridge that translates the vibrations into electrical signals to be carried along wires for the left and right audio channels. Only the cartridge is handled when placing the stylus on a record. This cartridge is affixed to a tone arm, which is connected by a hinge to the main body of the turntable. An adjustable tone arm weight is used to affect the amount of pressure bearing down upon the stylus. More weight may be desired when scratching, to reduce skipping, but will wear down the records and the stylus more quickly.

With an intimate knowledge of his or her vinyl, a DJ can develop a skill known as the “needle drop”, or placing the stylus at a specific sound within a record in time with the music. Visible changes in the groove spacing on the record surface make this easier. The moments of cueing a sound within a record are most often heard only in the DJ’s headphones before releasing it through the speakers at the right time. Using the needle drop as an audible part of a turntablist performance is a technique that was first developed by Grand Wizard Theodore, and demands a high level of hand-eye coordination to be done with musical accuracy. Theodore can be seen on YouTube performing a precise needle drop loop while blindfolded. The musical possibilities of the needle drop have been extended with specially created vinyl such as the electric guitar tone records by DJ Swamp, which map out a chromatic scale in sustained tones across the surface of the vinyl. For obvious reasons, the physical act of lifting the delicate stylus and placing it elsewhere on the record constrains the speed and articulation possibilities of this technique.

Features of the mixer

The mixer is the primary tool through which DJs perform their alchemy of combining disparate sounds into a new musical reality. In addition to its role as the conduit of synthesis, the mixer serves as an on/off switch and volume control for creating rhythm from the turntable’s signal. It must be considered as an equal partner to the turntables when considering the techniques of scratching as a whole.

The feature of the mixer that is most commonly used in scratching is the crossfader, which is moved horizontally to shift between one channel and another. When the crossfader is all the way over to the left or right side, only that channel will be heard. If the crossfader is placed in the middle, both channels will be heard. Many DJ mixers have only 2 channels. Those with more channels often have knobs that allow the user to assign which channels will be placed on the left and right sides of the crossfader axis. All professional DJ mixers are equipped with a knob that can adjust the crossfader’s curve when mixing the two sources. A soft curve allows a gradual fade in or out of either channel, while a sharp curve enables the smallest move of the crossfader to add one channel on top of the other. A sharp curve on the crossfader is the standard setting for most scratch techniques, which demand fast cutting in and out of a sound with the most economical finger movements.

The volume level of each channel in the mixer is most frequently controlled with an upfader, which is moved vertically. Each channel has its own upfader, usually with some level of control over the curve. If the crossfader is set to a sharp curve, then the upfaders are often set on a softer curve to allow more gradual variation in dynamics. The personal mixing style of a DJ directs how all of these faders are used, whether in blending or cutting.

Equalization knobs are located above the upfaders for each channel. Most typically, there are three controls here: one for the low range, one for the middle range, and one for the high range. The equalization knobs allow for the DJ to filter a layer of sound, transforming its character and providing it with a unique niche within a mix. DJs typically reduce or filter out lower frequencies on a sound that is being scratched.

Sounds may be previewed by the DJ using headphone cueing. Each channel has a button labeled PFL (pre-fader level), which sends it to the headphones. A separate knob controls how much this previewed channel is isolated or blended in the headphones with the main mixer output that is going to the speakers at that moment. The PFL buttons may also be used to send a particular channel to an external effects unit.

Basic Scratch Techniques

The first creative decision in scratching is selecting the appropriate samples. While any sound can be used in principle, certain types of sounds are best suited to the various techniques described below. Samples of solo instruments, a cappella vocals or spoken word, sustained tones, bands of noise, movie sound effects, and drums are the most commonly used sounds for scratching. In many cases, the sample itself will suggest a particular method of scratching, depending on the pitch content, envelope, and duration of the sample.

This type of scratch, also called a “cut”, involves the forward release of the record followed by a quick movement of the fader to the off position while the record is moved back to the same starting point. This is essentially a baby scratch with the reverse movement of the record muted.

NEXT: Turntables in the Digital Age