Ardour does not come with any built-in signal processors of its own (other than volume faders) but does ship, since v5.0, with the small group of plugins listed below. These plugins are listed as authored by "Ardour Team", which are LV2 plugins, and are named with "a-" as the start of the name (like a-EQ) or are listed as authored by "Ardour LUA Task Force" in which case they are example (but still useful) LUA scripts. These plugins use Ardour's generic GUI, and they work on all supported platforms so that projects started on one platform will sound the same on another platform—if they use just these plugins.

a-Amplifier
A versatile ±20dB multichannel amplifier
a-Compressor
A side-chain enabled compressor with the usual controls. Comes in stereo and mono versions
a-Delay
A basic single-tap delay line, with tempo sync
a-EQ
A nice sounding 4-band parametric EQ with shelves
a-Fluid Synth
Wraps the Fluidsynth SoundFont2 synthesis engine as a new sample player
a-High/Low Pass Filter
Independent high and low pass filters with steepness up to 48dB per octave
a-Inline Scope
A mixer strip inline waveform display
a-Inline Spectrogram
A mixer strip inline spectrum display
a-MIDI Monitor
A mixer strip inline display to show recent MIDI events
a-Reverb
A reverb that finds a balance between sounding good, using a lot of CPU and having too many controls