Synthesizer Part 3 (Digitization & Midi)

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Digitization & Midi

However, with digitization, this problem gradually disappeared completely. Digital sequencers could manage up to 1000 steps from scratch, which could be stored on floppy disks or cassettes. Nowadays, thanks to modern computer technology, there are almost unlimited possibilities. Initially, it was individual companies such as Roland, Oberheim, or Buchla, each of them developed its own sequencer. This is to be distinguished from the software sequencer. These are programs that can be installed on a computer; their advantage is that they are much easier to upgrade than hardware sequencers. The good thing about a sequencer program installed on a computer is, among other things, that the computer can always be used for other tasks at the same time. The communication between computer (with the appropriate program) or sequencer (hardware) and synthesizer now takes place via digital signal sequences, which were different depending on the manufacturer. The connection of devices from different manufacturers was made more difficult or impossible. Therefore, they created a common switch, called MIDI, which circumvented this difficulty. What it is and what it can do is discussed in more detail in the following chapter. But again, back to the sequencer. Using MIDI data, it was possible to record sounds or something similar on several tracks using the sequencer, then edit them and replay them via MIDI. A sequencer program that is used today is, for example, Cubase by Steinberg (now part of Yamaha) for Mac OS X and Windows computers. In addition, there is something similar for Apple Macintosh, namely Logic; other programs include Rosegarden, Sonar, Ableton Live, FL Studio, Bitwig Studio and Reason.


MIDI is an acronym, which is an initial for musical instrument digital interface, and refers to a serial port used to convey certain data for control between the synthesizer and the computer, even if they come from different suppliers. This first version 1.0 was released in August 1983. It had been developed by American and Japanese manufacturers. It was led by the Japanese Ikutaru Kakehashi from the Roland company and the American Dave Smith from the company Sequencial Circuits. Since that time, this standard has been constantly expanded and refined. A device has at least one of the following ports: an In, Out or Through port; Cabling is usually done with a 5-pin HIFI diode cable with a maximum length of 15 meters. The MIDI In jack is, as the name implies, the input of an apparatus that makes data usable. For data transfer, only the pins four and five are used on the jack for recording and playback. The speed of the data rate is 31.25 kbaud or 31250 bits per second. If you want to couple several devices together, this can be done via a series circuit or via a cabling, which is modeled after a star. For the former, so the series connection, a MIDI through connection is a prerequisite. With this connection, the input signal is forwarded unprocessed. In this circuit, up to three devices can be connected, but further disadvantages would result for the data flow. But if you have more than three devices, then in any case, the wiring in the manner of a star applies.

MIDI through box and operating modes

In addition, however, a so-called MIDI through box is needed, which distributes the signal to several outputs. The MIDI through box is also called a splitter. There is also the MIDI merger, which is the opposite of a MIDI through box. He has one output, but therefore it has several inputs. Finally, the data is sent via the MIDI Out socket. The information in the form of MIDI data, which for example is to be given to a synthesizer, can be controlled via two transmission paths, via channels, of which there are 16 pieces according to the MIDI standard, and via (channel) operating modes, in English they are called English channel modules, which take effect in the manner in which a receiving device receives the data. A distinction is made between the operating modes OmniOn, Omni-Off, Poly and Mono. In the first operating mode, Omni-On, Poly – also known as Omnia Mode – a synthesizer, for example, receives all data from the 16 MIDI channels. In the second operating mode Omni-On (Mono) a device can only be used monophonically. Precisely for this reason, it is no longer relevant to a modern synthesizer. In the third operating mode Omni-On, Poly – it is also called poly mode – the device can be used polyphonically. In the fourth mode (Omni-Off, Mono) – also called Mono Mode – data is passed on to each channel for a monophonic voice. It is not a single instrument referred to a MIDI channel, but individual voices of a device. If you work with a sequencer at the same time, the fourth mode proves to be particularly effective. In addition to the modes one to four, there is a mode that is referred to as Multi Mode. However, it is not an “official” part of the specification, but rather an extended mono or poly mode. In the following, we will now discuss some special features of MIDI communication.

The next part

Did you like this article about the digitation and midi? Share it in your favorite social media and tell us your opinion about the article! Do you want to get more information about the synthesizer? Click here to read the next part of the synthesizer series. The next part will tell you more about the midi.

5) Brockhaus encyclopedia
6) Audio Encyclopedia by Andreas Friesecke