7. Utility. Viscount DB-5

The same type of transfer of information is used to record MIDI sequences. A sequencer can be used to record the MIDI data transmitted by the OB5 or any other instrument.

When these recorded data are sent to the OB5, it will automatically play back the recorded performance.

CAUTION! Always use top quality cables for the MIDI connections from and to the OB5. We also advise the use of cables no more than 5 metres long.

MIDI Channels

The MIDI is able to transmit a multitude of digital data by means of a single cable and thus a single connector, thanks to the MIDI channels. There are 16 MIDI channels, so MIDI messages are processed when the channels of the receiver and transmitter instruments are the same. The OB5 is able to receive and transmit information on 3 MIDI channels simultaneously: one for the upper manual, one for the lower manual and one for the BASS section. The data relating to the instrument’s general information (the Vibrato Speed parameter, for example) are sent on the channel associated to the upper manual.

Main MIDI messages transmitted and received by the OB5.

The MIDI includes various types of messages used to communicate various types of data.

The MIDI messages can be subdivided into messages handled separately on each channel, and messages dedicated to the entire system.

The channel messages include:

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Note On: this message is transmitted when a note is played, i.e. when a keyboard key is pressed. Each Note On message includes the following codes:

Note On: when a key has been pressed;

Note Number: the key and thus the relative note which has been played;

Velocity: dynamic of the note (the force with which the key had been pressed).

Note messages are expressed as a number from 0 to 127, with Middle C represented by the number 60. Since its dynamic value is fixed, the OB5 always sets the Velocity value as 64.

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Note Off: this message is transmitted when the key pressed previously is released.

When it is received, the sound of the note of that key is deactivated. Each Note Off message includes the following codes:

Note Off: a key has been released;

Note Number: which key has been released;

Velocity: dynamic (amount of force) with which it has been released.

N.B.: A Note On message with Velocity=0 is considered equivalent to a Note Off message.

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Program Change: this message is used to select programs, given that many instruments have a large number of memories, each corresponding to a given program or timbre. Once you know the correspondence between the number assigned to the memory and the number of the Program Change, you will be able to select the type of sound you desire. By sending Program Changes 0 to 6, you will be able to select the seven Presets on the OB5, relating to the two manuals (and thus sent on the channels associated to the two manuals).

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