The ARP2600 requires a gate voltage of at least 10V to trigger its envelope generators. For the MCV4 or MCV24 the gate voltage has to be set to this value. Please look at the corresponding user's manual: MCV4 manual resp MCV24 manual (e.g. for the MCV4 the gate jumper has to be set to +U voltage gate and a external power supply with at least 10V has to be used, we recommend the usage of a 12V power supply for this application, for the MCV24 the gate level is software controlled).
The gate voltage of the MAQ16/3 corresponds to the power supply used for the MAQ16/3. Consequently a power supply with at least 10V (better 12V) has to be used for the MAQ16/3 to trigger the ARP2600. As the supply voltage range for the MAQ16/3 is 9...12V this is within the specified supply voltage range.
In addition the gate output of MCV4/MCV24/A-155/MAQ16/3 has to be connected to both gate and trigger inputs of the ARP2600. Otherwise the envelope generators of the ARP2600 will not start !