View source for Controllers and modifiers

==Controllers and Modifiers==

The Axe-Fx allows control over many of the various effect parameters. In essence
a controller is like a robot that turns a knob for you. There are two basic types of
controllers: internal and external. Internal controllers are automatic controllers that
are generated by the Axe-Fx based on various parameters and conditions.

External controllers are those generated by a MIDI device or a pedal for example.
A modifier is a transform from the value generated by the controller to a value given
to the parameter. Modifiers allow you to change the direction a parameter moves,
smooth the response and select which controller is attached to the parameter. A
modifier tells the robot how to move the knob.

===Controllers===
The Axe-Fx controllers are internal and external sources that generate control
information. This information can then be used to vary a parameter in real-time.
Internal controllers automatically generate control information, external controllers
generate control information based on input from the user, typically from the
movement of an expression pedal. The control information is given to a modifier
which in turn varies the desired parameter.

====Tempo====
The most fundamental internal controller is the tempo controller. The tempo
controller is special in that it cannot be directly connected to a parameter but many
"rate" or "time" parameters can be set to depend on it. To use the tempo controller
simply set the '''TEMPO''' parameter of the effect to the desired note duration. To set the
Tempo either turn the knob or tap the desired tempo in using the '''TEMPO''' button.
Tempo can also be tapped in using a pedal or MIDI CC message.
There are two tempo constructs in the Axe-Fx. The System Tempo is the tempo
currently being used. The Global Tempo is the last entered tempo. Entering a new
tempo automatically updates the System Tempo and sets the Global Tempo to
equal the System Tempo. The current System Tempo is saved with a preset during
a preset save operation.

Presets can either set the System Tempo to the tempo value stored in the preset,
which is the tempo at the time the preset was saved, or the Global Tempo. This is
done using the '''TEMPO TO USE''' parameter described below.
;
:'''TEMPO''' - Sets the current System Tempo. Whenever a tempo is entered, whether
:via this control or by tapping or by MIDI clock, the System and Global Tempos are
:set to this value. The Global Tempo is not affected by the tempo stored with a
:preset when the preset is recalled and remains in effect.

:'''TEMPO TO USE''' - Selects what tempo to use when recalling the preset. Selecting
:'''PRESET''' tells the Axe-Fx to set the System Tempo to the tempo stored with the
:preset. Selecting '''GLOBAL''' tells the unit to use the last entered tempo. If the value is
:'''PRESET''' the current tempo will change to the tempo stored with the preset, but the
:Global Tempo will remain at the last entered tempo. Recalling a preset with this
:value set to '''GLOBAL''' will load the Global Tempo into the System Tempo.

:'''AUTO DELAY''' - When set to ON, any delay blocks that are bypassed will become
active whenever a new tempo is input. This allows recalling a preset with a delay
block bypassed and then automatically activating the delay when tapping in a new
tempo.

====LFO's====
The Axe-Fx contains two Low Frequency Oscillators (LFO's) that can generate
various low-frequency waveforms for use in parameter modulation. The controls
for each are identical.
;
:'''TYPE''' - Sets the waveform type.

:'''RATE''' - Sets the frequency of the LFO.

:'''DEPTH''' - Sets the amplitude of the LFO.

:'''DUTY CYCLE''' - For all waveforms except sine this allows you to vary the shape of the
:wave.

:'''OUTB PHASE''' - Sets the phase of the secondary output (Output B). At maximum the
:secondary output is out of phase with the primary output (Output A).

:'''TEMPO''' - Locks the LFO frequency to the current tempo. This overrides the RATE
:control.

====ADSR's====
The Axe-Fx contains two Attack-Decay-Sustain-Release (ADSR) generators.
These can be use to generate sequences that can then be used to control
parameters. The graph shows the relative shape of the ADSR curve as its
parameters are adjusted.

;'''MODE''' - Selects the trigger mode of the ADSR:
:• '''ONCE''': The sequence plays when the threshold is exceeded.
:• '''LOOP''': The sequence repeats as long as the signal is above the threshold.
:• '''SUSTAIN''': The sequence stays at the sustain level until the signal drops below
:the threshold. The remainder of the sequence is then played.

'''RETRIG''' - When Retrig is on, sequences will reset to the beginning whenever the
:threshold is crossed from below to above.

'''ATTACK''' - The attack or rise-time of the sequence. This is the first line in the graph.

'''DECAY''' - The time to go from the peak level to the sustain level. The second line in
:the graph.

'''SUSTAIN''' - The time the sequence remains at the sustain level. The third, flat, line.

'''LEVEL''' - The sustain level in percent of full-scale.

'''RELEASE''' - The time to go from the sustain level to zero. The last line in the graph.

'''THRSHLD''' - The threshold level in dB. When the signal crosses this value the
:sequence is triggered.

====Sequencer====
The Sequencer generates a sequence of values. When the last stage of the
sequence is reached the sequence starts over. The Sequencer can be used to
generate repetitive patterns in time with the beat of the song.

'''RATE''' - Sets the rate at which the sequence is stepped through. A rate of 1 Hz will
cause the sequencer to step through the stages at a rate of one stage per second.

'''TEMPO''' - Locks the rate to the global tempo. Set to none for manual control of rate,
set to the desired time signature to lock the rate to the current tempo.

'''STAGES''' - Sets the number of stages in the sequence. For example, if STAGES is 3,
the sequencer will step through the stages as 1, 2, 3, 1, 2, 3, 1, etc.

'''STAGEn''' - Sets the value at that stage of the sequence.

''NOTE: The Sequencer features a random sequence generator. When in the Sequencer menu
pressing ENTER will load a random set of values into the stages.''

====Envelope====
The Envelope follower follows the envelope of the input signal. The harder you play
the greater the value out of the Envelope follower. The Envelope follower makes
possible dynamic parameter control such as ducking delay or touch-wah.

'''THRESH''' - The threshold level in dB. When the input signal is greater than this value
the output of the follower will track the envelope of the input with a rate set by the
attack time. If less than this value the output will decay at the release rate.

'''ATTACK''' - The rate at which the follower output follows signals increasing in power.

'''RELEASE''' - The rate at which the follower output follows signals decreasing in power.

'''GAIN''' - When using long attack times this can be used to compensate for the lower
output level from the follower.

====Pitch====
The Axe-Fx has a fast built-in Pitch detector. It is completely automatic and has no
adjustable parameters. The value from the pitch detector is proportional to the
frequency of the note played, higher notes give a higher value. If multiple notes are
played at once the pitch detector will attempt to find the lowest pitch but may not
be able to lock onto it. The pitch detector works best with single notes.

====External Controllers====
The Axe-Fx supports up to eight external controllers. You can attach these to the
'''PEDAL1,2''' jacks or to any MIDI Continuous Controller (see I/O setup).

===Modifiers===
Modifiers act as a “middleman” between the control information from a controller
and a parameter. The data from a controller is manipulated by a modifier and then
used to vary an effect parameter. The Axe-Fx contains 16 modifiers. In its simplest
form a modifier simply passes the data unaltered from a controller to a parameter.
For example, an LFO can be used to directly control the panning of an effect output.
Often times, though, you will want to manipulate the data from a controller. A
modifier allows you to change the response of a parameter to a given controller.
The first step in using a modifier is attaching it to the desired effect parameter that
you wish to control. To attach a parameter to a controller the parameter must
controllable. Controllable parameters are indicated by a symbol beneath the knob:
When the parameter is attached to a controller via a modifier the indicator has a
line through it indicating that it is attached. For parameters in a list, the symbol
above appears to the right of the parameter in the list.

To attach a controller to a parameter, select the parameter with the navigation
buttons then press '''ENTER'''. This brings up the '''MODIFIER''' menu.
Once the menu is brought up the modifier must be attached to a source controller.
This is the control information source that will be used to vary the parameter. You
can choose any of the internal or external controllers as a source (or none to
remove the modifier). Once the modifier is attached to a source you can vary the
response curve and the damping to suit the desired response.


[[Image:Controllable_Parameter.jpg|left|350px]]



<BR /><BR /><BR /><BR /><BR />To remove a modifier select the parameter with the navigation buttons and press<
'''ENTER'''. Set the source to none then press exit. This will remove the modifier and
restore the parameter’s value to its stored value.

====Parameters====

'''SOURCE''' - This is the controller that will be used to control the parameter. There are<BR />
a variety of different sources available:<BR />
;
:• '''NONE''' - Controller is detached.
:• '''LFO1A/B''' - Selects the 'A' or 'B' output of LFO1 (see above).
:• '''LFO2A/B''' - Selects the 'A' or 'B' output of LFO2 (see above).
:• '''ADSR1/2''' - Selects ADSR1/2.
:• '''SEQNCR''' - Selects the Sequencer.
:• '''ENVLPE''' - Selects the Envelope follower.
:• '''PITCH''' - Selects the Pitch detector.
:• '''EXTRNx''' - Selects an External Controller. There are eight external controllers.

These can be assigned to the pedal inputs or to MIDI continuous controllers
(see I/O Setup).
;
:'''START''' - Sets the start point for the transform.
:'''MID''' - Sets the mid point for the transform.
:'''END''' - Sets the end point for the transform.
:'''SLOPE''' - Sets the shape of the curve.
:'''SCALE''' - Sets the scale factor for the transform. The resulting curve is multiplied by
this value.
:'''OFFSET''' - Sets the offset. The curve is offset by this value

The '''SCALE''' and '''OFFSET''' parameters allow the user to position the modifier and
control the excursion once an initial transfer function is set with the other
parameters. For simple linear transfer functions, one need only use the '''SCALE''' and
'''OFFSET''' parameters, leaving the others at their default values.

:'''DAMPING''' - Sets how fast the output changes with the input. To slow the response
:rate increase the damping. This can be used to "de-click" a controller that changes
:rapidly.

This is especially useful when using controllers that have step-change responses
such as an LFO with a square-wave or sawtooth waveform or the sequencer. In
these examples the value of the controller jumps from one value to another
instantly. If these values are then connected to a parameter, that parameter will
jump from one value to another instantly as well. Many times this can cause an
audible click or pop, especially if the parameter is a volume level or frequency
parameter. By increasing the damping, the parameter will not jump to the new
value but slide to the new value at a rate dictated by the damping value.

The damping control is also effective when using an expression pedal to control a
parameter. It can help smooth out the pedals response, especially if the pedal’s
potentiometer has gotten “scratchy”.

====Detaching a Controller====
To detach a controller set the source to NONE and press EXIT.
[[Category:Controllers and modifiers]]