I posted this before on the old site, so here it goes again…
I selected the “Daily Blip” drum sampler preset, adjusted the A3 key to loop and adjusted its begin/end points until I got a pure 1Khz sine wave. Then I reset the envelop to a flat center line. That gave a 200mVpp continuous signal at max volume:
I increased the oscilloscope timebase to 10ms in order to better see the sound envelope. The sound starts at the left, at the “T” mark (we may see the noise floor displayed before that):
Turning the GREEN knob CCW attenuates the overall envelope. Notice how the signal amplitude goes down to 100mVpp:
Turning the BLUE knob CCW attenuates the attack portion of the envelope. The period is controlled by the ORANGE knob. Minimum period (20ms):
Maximum period (60ms):
Turning the BLUE knob CW boosts the attack portion of the envelope. This shows it peaking at 400mVpp:
This shows the envelope peaking at 800mVpp:
Again, turning the ORANGE knob CW will increase the attack period until the maximum below:
Turning the WHITE knob CCW attenuates the envelope part immediately after the attack. Note that this part is NOT related to releasing the key at all (if the key is released the sound stops immediately):
Turning the ORANGE knob CW causes of this part of the envelope to become longer but less pronounced:
Increasing even more:
Turning the WHITE knob CW boosts the envelope part after the attack:
The next pictures shows what happens when these possibilities are combined. Look at the OP-1 display to understand it:
Hope that helps understanding the drum sampler envelope better!