What is the timecode system - a brief guide to understanding the basics of the technology

The timecode system  (vinyl or CD) is designed to satisfy the needs of all those DJs who do not want and cannot give up the pleasure of touching the vinyl or the CD player.
This technology was created for the old system of open reel tape recording, then it was further developed for DJs working with vinyls, and afterwards it spread quickly to audio CDs in the form of digital files as well.
Thus you can use timecode with all turntables and CD players currently on the market.

Every software house (or at least the most "famous" ones) has produced an algorithm of its own, but in general all mixing software are compatible with timecode vinyls and CDs produced by other software houses. VirtualDJ, PCDJ DEX, Deckadance are compatible with timecode vinyls and CDs made by Serato, Torq, PCDJ, MissPinky, MixVibes, Traktor and others.
A timecode track has a duration ranging between 10 and 27 minutes, thus being much longer than any common audio track.

Simply speaking, DJ software that supports the DVS system (Digital Vinyl System) is controlled via a vinyl record or through jog wheels of CD players. What happens is that a turntable (or a CD player) should "dialogue" with the software by sending an audio signal comprising a specially designed algorithm.

How the timecode algorithm works

As for the last point, it should be noted that in case when the pitch slider is shifted, a variation of pitch is read and a variation of pitch bend is recognized at the same time. The latter action is performed by touching a vinyl record physically or, if a CDJ is used, by using a special jogwheel in bend mode.

When one of these situations takes place, the software will respond more or less rapidly, and you will see the result reflected in the waveform of the software. The speed of response depends on the latency (delay) which we set in the special driver settings menu of the sound card.

Latency in its turn depends on the following:
1) Sound card used (how fast it can handle data flows)
2) Software (how fast it can recognize a signal and give a response)
3) PC (or Mac) and hardware resources available

What you need to create a timecode system

In order to have a DJ console and use a timecode system you need:
1) Obviously, a computer and software supporting this technology
2) timecode vinyls or CDs
3) A sound card or a controller with a sound card having at least 2 stereo inputs and 2 stereo outputs

In the blog Http://it.virtualdj.com/homepage/cioce/blogs/2680/_ITA__Hardware_per_DiJ.html  you can find various sound cards and controllers with an integrated sound card, the inscription (2 Time Code OK) indicating that the sound card may be used with timecode.

Connections of a timecode system
This is one of the questions we receive most frequently from users who visit our forum ... Let's clarify it once and for all.

First of all, the sound card is connected to the PC via USB or Firewire. Please note that the operating system should recognize it and for this reason the installation of drivers (updated if possible) is essential and must be completed successfully.
The outputs of the turntable PHONO (LINE of CD players) should be connected to the inputs of the sound card.
The outputs of the sound card input should be connected to LINE inputs of the mixer.
In other words, the sound card is located between the turntable (or the CD player) and the mixer.

How the timecode system works

The timecode system can operate in 3 modes:
1) Absolute
2) Smart (intelligent)
3) Relative

The first mode emulates the vinyl perfectly, so, if you lift the turntable cartridge, the sound, of course, will stop, and, besides, when the stylus is shifted, the software follows the "jump" precisely from one point of the track to another.
The second mode is the most intelligent one, it allows, in the same way as the absolute mode, to navigate forward and backward within the track, but the beginning of the track itself is not tied to the physical location of the timecode disc beginning.
With the relative mode, however, you avoid leaps of the stylus, and the audio stream will not be interrupted even if there’s intense vibration or leaps of the cartridge which appear because of intensive scratching. In this mode shifting the stylus forward or backward does not change the position of the track.

All types of software that support timecode have a very useful feature, which allows DJs to play vinyls and CDs containing "real" audio tracks instead of timecode ones. Thus if a DJ has a track on a vinyl (or on a CD) not in the digital format (MP3), he can use this feature and play that track in a traditional way.
This function is called "Bypass", and it is displayed on the screen of various types of software. Otherwise it can be activated by assigning the corresponding command to a key of the keyboard (or of the controller).

Advantages of timecode

- The same tactile sensations as those given by a turntable, both with scratching and with pitch bend.
At present this is still the best way to do scratching when using digital files, and it is very useful for those who mix hip-hop music. Just think of DJs who could only do scratching with vinyls they bought; if they wanted to use their own grooves or samples, they had to have special vinyls made.
It is also possible to get pitch bend by touching the vinyl, in contrast to motorized platters (like Numark NS7 or Denon DN-S3700) where, unfortunately, the simulation is not yet perfect.
- You don’t have to carry lots of vinyls (or CDs) with you because, thanks to two timecode vinyls (or CDs), you can "play" all digital tracks which you have on the hard disk of your computer.

Drawbacks

- As a technology that combines the world of analogue devices to that of digital ones, one of the flaws of the timecode system is that it limits the user in the number of software functions. In fact, apart from the inevitable "play-pause" functions and the complete control that you have over the disc, timecode doesn't give access to any other functions of the software.
- All other features (loops, cue, effects, samples, etc.) must be activated/modified with help of the mouse and the keyboard or via an external MIDI/HID controller.

That is why this system is recommended only to those DJs who cannot do without a vinyl and who have a certain computer confidence, considering the variety of settings you can adjust.
It is also worth mentioning that in order to  work properly a timecode system requires a lot of PC hardware resources (RAM and CPU in particular), a sound card which handles the data traffic quickly and an optimized operating system without unnecessary programs  which can slow it down (like antivirus programs, firewall, etc.).
This is even more true if you choose to mix video clips instead of audio files.

Possible problems and their causes

If you hear "clicks and pops" or if the audio "stutters", in 99% of cases it may be caused by the following:
1) Hardware resources are not sufficient (the computer is too old)
2) Low performance of the sound card (not good enough to handle the data traffic)
3) Operating system is not very efficient and optimized

Demonstration videos

In this video you can see sound card Hercules Trim 4 & 6, which is particularly suitable for application with timecode vinyls and CDs. Please pay close attention to it starting from the sixth minute, there's a voice description accompanied by images which explain what a timecode system is.

You will see Virtual DJ 5 connected to sound card MAYA 44 (which is very economic) in this second video; it is used in timecode CD mode together with the famous Pioneer CDJ-1000.