A-140 ADSR Envelope Generator

(Almost) everyone has an A-140 ADSR Envelope Generator. For a good reason: the envelopes can be extremely “snappy” if necessary, but due to a three-stage “Time Range” switch very slow times are possible as well.

The features of the module are solid and well thought-out standard: a gate and a retrigger input, three outputs for the envelope, one of them with inverted voltage. The duration of the envelope curve is between a very fast 50 µs and a few minutes.

User interface


System bus: Similar to the oscillators A-110-1, A-111-1 and A-111-5, the A-140 can also be controlled via the system bus. Gate signals present there (e.g. from one of the midi interfaces) start the envelope as an alternative to an externally supplied voltage at the “Gate” input (switching socket that interrupts the line from the bus).






Lots of output jacks are useful

The A-140 can be used wherever a “normal” envelope generator is required. The three outputs are particularly advantageous for very small systems with only one envelope generator: One controls the VCA, the second (or the inverted) output controls the filter.

A simple synthesizer where the A-140 controls both VCA and VCF (inverted output).

In the endless loop

An A-140 ADSR in “endless loop”.

Together with an A-167 Comparator, an ASDR signal can be generated that keeps restarting – like an LFO. To do this, one of the A-140 outputs is connected to the “+In” input of the comparator, the “Inv. Comp. Out” (inverted comparator output) generates the gate signals for the envelope.

It is best to start with the “+In” control set to “12 o’clock”, “Gap”=0 and a high control value of “Offs”. Now slowly decrease “Offs” until the A-140 is triggered. If necessary, the frequency can be lowered with slightly raised “Gap” values.

Technical specifications

Width8 HP
Depth50 mm
Power requirements20 mA (+12V) / -20 mA (-12V)