Oberheim OB 12 Operating Manual - page 15

OB   12

Z-Domain Synthesizer

 5.2 PROGRAM, TIMBRE and SYSTEM

135

The internal memory is mainly subdivided into four large sections:

1. the memory section reserved for the PROGRAMS (and thus the PROGRAM operating

environment)

2. the memory section reserved for the TIMBRES (TIMBRE operating environment)

3. the memory section reserved for the SYSTEM UTILITIES (SYSTEM operating environment)

4. the AUTOMATION section, comprising the ARPEGGIO, PHRASE RECORDER and MOTION

RECORDER functions.

We will now take a detailed look at the first three sections.

THE PROGRAMS

The OB-12 contains 256 Programs, 128 in bank A and 128 in bank B, completely programmable

and all memorisable.

A Program can be set with up to four Parts containing one Timbre each, and offers the possibility

of configuration with four different timbres. Naturally, this example is purely guideline, since it is

not always necessary to set a Program with four parts and thus with four different timbres.

As well as containing the Timbres, the Program also allows the addition of effects and equalization

of the sound generated by the timbres, regulation and performance of arpeggios, configuration

of the outputs, and other useful functions which we will be looking at later.

Refer to section 9 of this manual for all necessary information about the Programs. In addition,

section 7 describes the panel controls of the sections associated to the Programs (Effects,

Arpeggio, Phrase Recorder and Equalizer).

You can access the PROGRAM operating environment (which is also preselected when the

instrument is switched on) by pressing the [PROGRAM] button in the MODE&SET-UP section of

the central panel. Once the selection has been made, the LED of the key illuminates and the

following video page appears in confirmation:

THE TIMBRES

A Timbre is the basis of the sound you produce using the Program. However, while you cannot

play a Program unless it contains at least one Timbre, the Timbre itself can be played on its own,

regardless of the Program settings, by enabling the Timbre operating environment.

The OB-12 memory contains 256 Timbres, 128 in bank A and 128 in bank B. The internal structure

of the Timbre is essentially as shown below:

As the diagram in the next page shows, this generation chain consists of four main components:

-

OSC.1 and OSC.2: which generate the two waveforms (which as we will see, can be the

result of three signals for each oscillator);

-

FILTERS: programmable combination of two filters which attenuate the unwanted harmonics

of the signals produced by the oscillators, and thus control the brightness of the sound;

-

AMPLIFIER: which controls the level of the signal leaving the filters:

and then by a further five sections which control the four main ones: