<p>A ‘processor’ is a thing which treats the signal in some way. Ardour provides several builtin processors, such as the "fader" processor which controls the gain (volume) of a track or bus. Processors can also be plugins used for effects or as instruments, as well as sends/inserts which are used to change <ahref="/signal-routing">signal routing</a>. The arrangement of processors is arbitrary, and there is no limit to how many there can be.</p>
<p>The main box in the top half of a mixer strip shows the processor list. Processors are shown as coloured rectangles, with a small ‘LED’ beside them; this indicates whether or not the plugin is enabled, and can be clicked to enable or disable a processor. The colour of the processor depends on its location in the sequence; processors that occur before the fader are coloured in red, and those after are coloured green (in the default theme).</p>
<p>The processor box will always contain a blue processor called ‘Fader’. This indicates where in the processor chain the main volume fader is located — this is the fader shown in the lower half of the strip.</p>
<h2>To Reorder (Move) Processors</h2>
<p>Processors can be re-ordered using drag-and-drop. Dragging a processor allows it to be moved around within the chain, or copied to another processor list on another track or bus.</p>
<h2>To Enable/Disable a Processor</h2>
<p>To the left of the name of each processor is a small LED symbol; if this is lit-up, the processor is active. Clicking on it will deactivate the processor. It will still pass audio or MIDI signals, but they will not be affected.</p>
<h2>Adding Processors</h2>
<p>Finally, processors can be added to or removed from the chain. Right-clicking the processor list does three things:</p>
<ul>
<li> A gap is opened up to indicate the location of the click. The gap shows where any new processors will be inserted.
</li>
<li> The processor under the click is selected.
</li>
<li> A menu is presented giving options of what to do.
</li>
</ul>
<p>From the menu, some new processors can be inserted.</p>
<h2>Removing Processors</h2>
<p>Context-click on the processor you want to remove. </p>
