In old times, when we just had learned to record cylinders or discs, playing music was simple. Just put a disc on the player. With the invention of the tape recorder we even were able to play pre-recorded lists of music. All this really became different with the invention of computers and audio file formats.
Today, we can have hundreds of thousand single musical files on hard disk easily transportable. Even the invention of the CD has made that much easier, but carrying 200 CDs is still today a weight not easy to ignore for a DJ. For the DJ everything is quality, handling and easy accessibility of required tracks. This can be really tricky if you juggle with 200 CDs, it also can be a matter of seconds, when you work with tagged music files and a powerful database.
Even if today some DJs like to play vintage vinyl, the days of the record player or even the CD player are over. Some DJs still use CDs (they have good reasons for this), but most modern DJs use computers, which is really convenient.
First let us look at record players. They are perfect for playing vinyl records. The problem here is that DJs want to create a certain sequence of tracks, so we need two players. Actually this will make it difficult to play two tracks from the same record and we need some extra equipment to connect both players. The real challenge is to carry all the records. A typical Tango DJ will need at leaste 50-200 Records. Estimating the weight of a Vinyl to be around 180g, we calculate 18 kg for 100 records. and around 2 crates with a good system to keep that organized.
So I haven´t seen Vinyl DJs in Tango during the last 10 years. In other musical styles, scratching with vinyl either analog or digital is still popular.
CDs, invented in the early 80ies are versatile, have good quality without scratches and hiss and are easy to carry. So still today lots of Tango DJs are playing with CD players. CDs can be individually recorded and always provide a good digital quality. This means, the music is digitized into numbers and stored on the surface of the CD, where it can be read with a laser beam.
Again, you will need two Players (DJs call them decks) and some equipment to connect both. CDs can have a certain weight as well. If the CD comes in a jewel case, the weight of one CD is around 100g, 100 CDs would then weigh 10 kg. But the volume is smaller.
The same problem of not being able to play two tracks of the same CD in a proper way applies to CDs. Clubs DJs typically play with two seperate decks, in many venues, dual CD players are provided.
Computers or digital Players
Computers easily can store and calculate digital information. So the idea to use the already digitized data from the CD and store it on a harddisk is logical. Unfortunately, Computers had problems to store a huge amount of data during the 80ies and partly during the 90ies. But then storage became increadibly cheap and also methods of data compression specially for music have been invented. Nowadays, Computers are able to store 10,000s of musical pieces and they are also able to search and retrieve music in moments. For this, we just need enough space on the internal or an external Harddisk and a Software to handle this. For mobile DJs typically mobile Computers are used like Laptops, Pads or small dedicated Music players. Typical systems used here are Apple Notebooks or PC/Windows style notebooks.
Computers have to transform the music data from the digital format into an analoge signal, which can be hooked up to other devices. This step is typically called decoding. In older Computers, a “sound-card” was used for this. Modern Computers have Chipsets onboard. Typically these devices only provide one audio output, which is not sufficient for DJ use (we need actually 2-3 outputs, one per deck and a headphone connection for prelistening). Additional to these restrictions, consumer sound-cards are limited in quality .
So for typical DJ use, external sound-interfaces are digitally connected to provide these necessary Outputs and also inputs for certain additional signals. Today external audio-interfaces are connected via USB2 to provide speed and quality. Some of these devices have better quality chip decoder, so the use in semiprofessional environments is possible.
For semiprofessional or professional DJing, two decks have to be connected to a device, which can control the input of the speaker system. Typically this device is called a mixer, because it can blend between the decks and other input channels like a microphone. Dj Mixers typically have 2-5 input channels and one or two outputs. Additionally they provide an output for headphones, which is usually used to prelisten one deck, while the other deck is playing. The Channels of this mixer are controlled usually with drawers. Some Mixer have an additional crossover drawer to blend between two decks. For traditional players, the typical setup is two decks and one DJ-mixer.
Digital DJ-controller are a mixture of a digital mixer and an external sound-interface. This means, they are mixers, which control the DJ-Software in the Computer. Additionally, the digital output of the computer processor is then decoded with more or less quality decoding chips. Typically DJ controller look like a combination of CD players and a mixer. In general, they are cheaper than stand alone equipment and because they are perfectly connected to the DJ software, they can provide better quality of workflow.
The combined audio signal of the Mixer is usually fed into the actual sound system. Traditionally it consists out of one or more amplifiers and a quantity of 2++ speakers. The traditional approach was to have seperate amplifiers and speakers, today the use of so called active speakers is more common. These are speakers with the amplifier built in, so that actually the output of the mixer is directly fed into the speaker.
Today the idea is that speakers should be small, but many of them should be used. They are also not to be used outside their specifications. F.E. for deep frequencies, special speekers (Subwoofers) are used, for the higher ranges, small active speakers are sufficient.
Is this for Tango ?
How about Tango DJing. I personally think that the time of vinyl and CDs is over and the minimum equipment today is a computer and an external audio interface with the possibility to prelisten. Naturally, there is always the option of choosing semiprofessional equipment, F.E. a DJ controller. If you need to provide additional inputs, this can be handled by the DJ controller. Another option is to use an external audio device and rout the outputs into a traditional DJ-mixer. This will be the way to go in the future to assure that all stages of the sound chain will be digital and the final conversion to an analog signal will be of highest possible quality.
-Richard (DJ Ricardo)