Pitch Control
Audio being looped by Buffre normally plays back so that repeated
events sound identical to the original audio signal. Playback speed, or
more accurately, playback sample rate can be manipulated by using
the Pitch Knob or Keyboard Transpose controls.
Because
manipulation of the sample rate directly alters both pitch and time, this
process will alter the looping cycle speed, and looping loses
synchronization with the song document tempo.
The Pitch Knob scales the sample rate between -4 Octaves and + 4
Octaves. This translates to 16 times slower than original speed up to
16 times faster than original playback speed. Pitch can be adjusted in real-time to
simulate the effect of a tape stop. This works particularly well with a 1/2 note or longer
playback loop.
Pitch (Cents)
The default setting for the Pitch knob is a percentage mode where the sample rate is
altered freely between -4800 cents and +4800 cents. A lamp indicator at the 12:00
o’clock position directly above the knob will illuminate when the value is anything but
zero. As you move the knob away and back towards 0, the knob position will snap at
the vertical point and the lamp will go off. The scaling is non-linear and non-symmetrical
by design. If you prefer a linear scale, switch to Pitch Step mode by pressing the
SNAP button.
Pitch (Half Steps)
When the Pitch Snap Button is enabled, the Pitch control knob changes to a stepped
scale that alters the setting in half step, or 100 cent, increments. The 12:00 o’clock
position is zero. Adjusting the knob counterclockwise will decrease the pitch and
playback speed in half step increments down to -48 half steps or 4 Octaves. Adjusting
the knob clockwise from zero will increase the pitch in half step increments up to +48 or
4 Octaves.
Keyboard Pitch Control
The loop engine sample rate can also be altered via MIDI by pressing a key in the two
octave range between C-1 and C1. C0 sets the playback pitch to normal. Playback
speed/pitch increases in half steps for one octave up to C1, and decreases in half steps
from C0 down to C-1.
When a Keyboard Pitch Transpose message is received, the Pitch Control knob is
defeated while the transpose key is held down. When the key is released, Buffre
resumes looping at the amount set by the Pitch Knob.
v1.0.2 operation manual
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