The ENV/LFO/Filter section has three sub-tabs that select the target for three separate envelopes. The default one, and the one discussed above, is the volume target. You can select the target in the same way that you select the tab in the instrument, by clicking on the label. To control the envelope, you have six knobs to set each of the above parameters - pre-delay (DEL), attack, hold, decay, sustain, release - and a 7. one to control the amount (AMT) of the effect that the envelope has on the parameter.