Doepfer A-140-2 Dual Micro ADSR

The module contains two ADSR type voltage controlled envelope generators with exponential curve shapes (charge/discharge curves of a capacitor) behind a front panel with 8 HP only.

Each ADSR provides these controls and in/outputs:

- LED (displays the envelope output)
- A: manual Attack control
- D: manual Decay control
- S: manual Sustain control
- R: manual Release control
- Gate Input (min. gate level: +5V, max. gate level: +12V)
- Retrigger Input (min. retrigger level: +5V, max. retrigger level: +12V)
- CVT Input with attenuator (CVT = CV Time)
- Envelope Output 1 (normal envelope output)
- Envelope Output 2 (selectable between normal and inverted envelope by means of an internal jumper)

The output voltage range for each envelope is 0 - 10V (10V = attack peak).
The time range of Attack/Decay/Release is about 1ms to 30s.

By means of internal jumpers one can select which time parameters are controlled by the CVT input (e.g. D only or D+R or A+D+R) and in which direction (i.e. if an increasing CVT shortens or stretches the time parameter in question).
Socket CVT can be normalled to an internal fixed voltage (i.e. the switching contact is connected to an internal fixed voltage). That way it's possible to change e.g. all time parameters simultaneously by means of the CVT control.
Another jumper is used to set output 2 to normal or inverted envelope.
And another jumper is used for the normalling of Gate 2 to Gate 1 (i.e. ADSR#2 is also triggered by Gate 1).
Two more jumpers are used for the optional bus access to the gate signal of the bus for each ADSR.

Changing the positions of the mentioned jumpers allows to modify the factory settings. The following document shows the positions and functions of the jumpers of the module: A140_2_Jumper.pdf

The basic functions of an ADSR envelope is described in the user's manual of module A-140: A140_man.pdf.
The voltage control of envelope parameters is mentioned in the user's manual of module A-141: A141_man.pdf. But the A-140-2 has only one control voltage input CVT with attenuator available and one has to decide via the jumpers which parameters are controlled by CVT and into which direction.

Additional technical information:

The voltage level of the used gate signal has to be at least +5V and the rising/falling slopes has to be fast enough. Otherwise the envelope will be not work in the right way. We discovered that some modules from other manufacturers do not meet these specifications. In this case the level shifter module A-183-4 may help by connecting one unit of the the module between the gate source and the gate input of the A-140-2.