User's Manual

6.4. Envelopes
The Envelopes generate a container for the sound, shaping them over time each time you
touch, hold, and release any key on the keyboard. You will find two envelopes on the JUP-8
V4:
• ENV-1 is typically used as a filter envelope that modulates the cutoff frequency
of the VCF (and can be used as a pitch or PWM envelope for the VCOs)
• ENV-2 is typically dedicated to provide an amplitude envelope to open and close
the VCA. It can open and close the VCF at the same time if desired, instead of
ENV-1. If the levels of all points on ENV-2 somehow get set to zero, you won’t hear
anything when you play. (The default ENV-2 setting has a very fast attack time
with a sustain level set to maximum (1.00) and a fast release, so usually this isn’t
a problem.)
When playing the keyboard, the envelopes will trigger and modify the voices over time. Each
envelope has 4 different controls, labeled A D S R:
• ATTACK: The Attack is the time that the sound will take to reach its maximum
volume once we have pressed a key on the keyboard.
• DECAY: The Decay is the time that the sound will take to diminish after the attack
portion is complete.
• SUSTAIN: The Sustain is the maximum volume level that the sound will reach
after the decay is complete, and it will hold at that level as long as you hold the
key.
• RELEASE: The Release is the time that the sound will take to diminish once the
key has been released.
• KEYFLW: These switches connect envelope 1 and/or 2 to the keyboard follow.
When the switch is “ON”, the envelope times – “A”, “D” and “R” – will be shorter as
you play the higher notes on your MIDI keyboard, to mimic the typically-shorter
envelopes of higher notes on acoustic instruments.
• POLARITY: Switch to set the polarity for ENV-1:
◦ If the switch is on the top, the envelope polarity is positive (this is the
usual way to use an envelope).
◦ If the switch is on the bottom, the polarity is negative (or reversed).
This means that the envelope will close the filter instead of open it, or
lower the VCO pitch instead of raise it. A high sustain level will keep
the filter closed; a low sustain level leaves it open. The Attack phase
now shuts down the filter, starting it loud then fading it, instead of the
reverse. Try it and see.
Reversed polarity is very useful to create some inverted effects. Take a look at the preset
“Bouncing Balls” to hear an example of this special effect, and the difference between
holding the key and releasing it.
Arturia - User Manual Jup-8 V4 - HPF and VCF Filters, VCA, and Envelopes 42