DOEPFER A-143-2 Руководство - Страница 2

Просмотреть онлайн или скачать pdf Руководство для Оборудование для звукозаписи DOEPFER A-143-2. DOEPFER A-143-2 6 страниц. System a-100, quad adsr

Quad ADSR A-143-2

2. Basic Principles

Fig. 2 shows the basic function of each unit:

Fig. 2: Basic function

The positive edge of the gate input starts the envelope

signal and resets both the "End of Attack (EOA)" and "End

of Release (EOR)" output. The time required to reach the

maximum value of the envelope is defined by the attack

control. As soon as the envelope level reaches the sustain

level during the rising slope, the digital "End of Decay

(EOD)" output turns low. As the maximum value (about +8

V) is reached, the EOA output turns "high" and the so-called

Decay phase begins. In the decay phase the slope falls to

System A-100

the Sustain level defined by the sustain control with a time

adjusted by the decay control. At the end of the decay

phase the envelope output remains at the sustain level until

the gate signal turns low. When the gate signal turns low the

EOD output turns high and the Release phase of the

envelope begins. The slope falls to zero with a time adjusted

by the release control. When the envelope level reaches

about +0.5V the EOR output turns high.

The retrigger behaviour of the A-143-2 is different compared

to other envelope generators. During the attack phase the

envelope cannot be retriggered or reset. During the decay

phase the envelope direction changes if a positive edge

appears at the retrigger input (i.e. the envelope changes

from decay to attack state).

Fig. 3: Retrigger behaviour

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