Why do people use turntables

Turntables on stage: you should definitely pay attention to this live on stage

Turntable tools and tips for the pulpit and stage

(Image: Daniel Günt)

When the turntable was still regarded as the only true work tool of the lay-up guild and was used by them, you didn't have to worry about the structure and condition of the record player. Constantly serviced, built into the pulpit to be bass-resistant, the turntables turned without deviating from the vinyl track. The club even provided pickups. In the meantime, CDJs and controllers have displaced the former analog top dogs in many places, partly because of the comfort, partly because of the disastrous maintenance of the classic Technics SL-1210 MK2.

In order to meet the constantly growing demands of technical riders, the club often prefers to rent DJ equipment, unfortunately the turntables occasionally show functional flaws. The pulpit is universally dished out so that any player can universally bed on it, it harbors acoustic handicaps for the turntables. It hums, couples and jumps, but why and what do you do about it?

The physical causes

Apart from shocks, vibrations, rumble, feedback and resonance cause the needle to go off course. Coarse vibrations occur as a result of bumps, while finer vibrations occur as a result of impact sound. When it comes to feedback, vibrations and resonance, it takes a little look into audio theory to understand it.

Pickups, the needle of which causes a magnet enclosed by coils to generate electrical voltage while driving over the vinyl, also pick up noises from the loudspeakers, provided they are in the immediate vicinity.

The signal reproduced via the drivers is mixed again with the sampled signal, a kind of overdubbing. However, this constantly repeating loop creates an initially quiet and steadily increasing hum in the low frequency range, which can ultimately even destroy the bass driver of the loudspeaker box. Rumbling is understood to mean additionally induced voltages in the pickup, which are not caused by the groove scanning, but by mechanical interference.

In the case of resonance, a more physical background is required, which does not only refer to the pickup, but also as a unit with the tonearm. Both physically work together as a spring pendulum with a natural frequency. In addition, the spring-loaded sub-chassis in hi-fi models are based on the same principle. If the tonearm and the pickup are excited during playback with a frequency identical to the natural frequency, resonance occurs and this "spring pendulum" swings. Vibrations, distortions and even needle jumps are the result.

The structure of the desk

To prevent vibrations and resonances, you have to decouple the turntable (here our special on the subject of turntables) from the sources of danger and thus interrupt disruptive vibrations:

1. Do not position the turntable in the immediate vicinity of the monitoring system, if possible not on the same table, because the monitor box literally dances with the loud bass on the desk. Shock-like impulses and shocks occur. If a flexible, not permanently installed monitor box is available, it is better to place it on the floor on a tripod. This also prevents bass resonance, vibrations and feedback.

2. The DJ booth should not be connected to the pedestal on which you are standing. Otherwise the needle will jump even with your smallest dance interlude. Explanation: At events, festivals or parties, the DJ pulpit is often made up of cross-built stage platforms, so-called Bütecs. Through this stabilizing cross construction, vibrations triggered by impact sound are transmitted. Therefore, it is better to separate the Bütec you are standing on from the DJ desk and set it up as an independent unit, not lashing it together and also leaving a gap as play.

3. More complex, but even more effective against all of the above-mentioned disruptive factors, plus a visual eye-catcher: the free-swinging DJ desk, either suspended from the ceiling or on a traverse.

Solid stone slab as an absorber

Turntable, tonearm and system

DJ turntables such as the Technics SL-1210 MK2, Pioneer PLX-1000 or Reloop RP7000 or RP8000, which can also be found in our test marathon DJ turntables, counter the “troublemakers” with their massive chassis and the associated weight of sometimes over ten kilograms. The vibration-dampening feet, especially the silicone-filled models of the new Technics SL-1200GR / 1210GR, also counteract this.

With the settings on the turntable and the right choice of cartridge, you can gain additional performance. In general, the following applies: Never use too much contact weight, because both the needle and vinyl wear out faster, especially since distortions occur. But if it constantly couples and the needle jumps permanently, it's better to jump over your own shadow. A hard needle suspension can handle 1 to 1.5 grams more than the recommended weight. However, if the stylus almost grinds on the vinyl due to a softer suspension, less is more.

You can tell whether a pickup has a soft or hard suspension by the contact weight recommended by the manufacturer and by the tracking value, which already suggests softer material in the needle suspension at 80 micrometers. There are also pickups that are specially tailored to acoustically difficult club use, such as the Ortofon Concorde Elektro. Its vibration-reducing rubber tube reduces unwanted interference due to bass-heavy music. A high output voltage reduces the risk of feedback and speaks for a very good signal-to-noise ratio in order to more precisely separate the sampled signal from interfering noises such as those from the monitor.

Do it yourself

There are pictures of the craziest ideas on how to make the turntable resistant to shock and vibration as well as decoupling the bass. I advise against constructions made of towels or toilet paper rolls that are in danger of collapsing. It is better to use massive stone or metal plates as a bass absorber and the troublemakers bounce off like a wall. In addition, this symbiosis of robust base and turntable gives more security when scratching, because the additional heavy weight of the base plates keeps the wobbling of the turntables and the desk in check.

Metal plates with squash balls counter vibrations (Image: Daniel Günt)

Squash balls or tennis balls cut in half reduce the contact area between the turntable and the table. First, the balls are placed in the estimated position of the turntable's feet, then the stone slab and turntable are placed on top. If necessary, readjust the balls a little so that they are exactly under the feet of the turntable, because it is precisely at these four points that the interference must be attenuated, and this is the only way to ensure that the stone slab is exactly horizontal and does not tilt.

The catch: this construction is a bit spongy, especially DJs who like to handle the vinyl a little more roughly when scratching, have to get used to the vertical yield of the drive when pressing on the record and handle it more carefully. Otherwise it jumps!

Tools

If the organizer does not offer a solution, the DJ has to do it himself. How about, for example, the inflatable air cushions called "Freefloat". They absorb shocks and vibrations, depending on the amount of air, thanks to their flexible elasticity and rolling effect of the four air balls, which are connected diagonally via air hoses to a fifth ball in the middle for stabilization.

The danger of the needle jumping is reduced by a factor of 10 to 20. Higher volumes can be used, there is no rumbling in the usual frequency range. The bonus: They are cheap, take up no weight and hardly any space in your luggage.

The massive anti-shock absorber Luke ASB-1 combat the annoying side effects even better. Record players and CDJs are very stable in the recesses. Between two birch plywood panels bonded under high pressure, there are five special foam dampers that absorb disturbing sound signals, vibrations and the resulting shocks. Due to their open construction, the ASB-1 specifically minimize the oscillation in the critical frequency range of 50 to 450 Hz. The robust workmanship justifies the price, but in a double pack of just under eight kilograms also the heavy weight.

A professional gadget

Not cheaper, but more comfortable for on the go: MK Stands Over Feet. They grasp the evil of the resonance and the vibrations at the root, or rather at the feet, which are adapted to those of the Technics SL-1200/1210 MK2 or Pioneer DJ PLX-1000. The handy absorbers, made of special rubber adhering to the surface, are pulled over those of the turntable. Even if the turntable is standing directly on a bass box, it can hardly be disturbed when playing.

Similar in approach, but more filigree with a touch of high-tech, the Isonoe Iosolation System feet, which have been manufactured in the UK since 2004, can be screwed on or can be universally placed underneath, tackle the acoustic problem. Even Sven Väth swears by this product, because it even combats the deep bass, which is particularly causing feedback and vibration, when it booms under enormous sound pressure levels directly from the speakers next to the turntables.

Often used at festivals

The absorbers, which are made from a magnesium alloy using a CNC machine, score with great precision thanks to their cushioning bushing and the ball bearing underneath. The latter reduces the contact points between the vibrating surface and the turntable. The Isonoe Iosolation system feet are the most expensive, but also the safest and most stylish.

You can find more tools, accessories and gadgets for DJs in this test marathon.