Chapter 2: Playing the A6
62 ANDROMEDA A6 REFERENCE MANUAL
CURVE: Selecting the Portamento’s Slope
Identical to the stages of an envelope, Portamento has a user-selectable property
called slope. This term refers to how gliding notes accelerate (speed up) or decelerate
(slow down) as each voice approaches its target note:
•A
LINEAR slope means that gliding notes do not accelerate (or decelerate) as
they progress towards their target (destination) notes. In the illustration on the
next page, notice that the linear slope is depicted as a straight line (from where
we get the term “linear”). The glide doesn’t speed up or slow down but keeps
an even rate of change.
• An EXP (exponential) slope, however, accelerates towards the target notes: it
starts out slow then speeds up as it gets closer to its destination. Rather than a
straight line, it is represented by a curve. One of three exponential curves can
be selected.
• In contrast, the LOG (logarithmic) slope decelerates towards the target notes: it
starts out fast then slows down as it reaches its destination. It is represented by
a curve that is the opposite of the exponent. One of three logarithmic curves
can be selected.
• The SCURV (“S” Curve) combines the slopes of EXP 2 and LOG 2. One of two
S-Curves can be selected:
SCURV1: The rising-amplitude of S-Curve 1 is characterized by acceleration
during the first half of its stage using EXP 2, then decelerates during the last
half using LOG 2. This is commonly known as a forward progression s-curve.
The falling-amplitude of S-Curve 1 is the opposite of its rising-amp: the stage
decelerates during the first half using LOG 2, then accelerates during the last
half using EXP 2.
SCURV2: The opposite of S-Curve 1 – commonly referred to as a reverse
progression s-curve – the rising-amplitude of S-Curve 2 decelerates during the
first half using LOG 2, then accelerates during the last half using EXP 2.
The falling-amplitude of S-Curve 2 accelerates during the first half using EXP
2, then decelerates during the last half using LOG 2.