Control the Meris Mercury X from your browser — full MIDI CC reference for 23 parameters, interactive editor, and AI-generated presets. Free, no install.
Nitelite gives the Mercury X a full browser-based control surface: turn every knob, flip every switch, describe the tone you want to the AI Tone Terminal, and save the results — all sent to the pedal live over MIDI (default channel 1). Works free in Chrome, Edge, Opera, or Brave — no install required.
Knobs
Control
MIDI CC
Description
DECAY
CC 33
Reverb parameter 1 — function changes per Reverb Structure. Decay (Ultraplate/Cathedra/Prism/Gravity), Dwell (Spring), Mids (78 Room/Plate/Hall).
PREDELAY
CC 15
Predelay time — twin 2.54s delay lines with 32-bit resolution, expressed in seconds or BPM
MOD
CC 21
Modulation applied to delay lines — linked to front panel Mod knob. Different voicing per Delay Type.
MIX
CC 1
Balance between dry and wet signal — directly connected to front panel Mix knob
FEEDBACK
CC 19
Delay line feedback amount — sets feedback for both L and R delays
CROSSFEED
CC 20
Cross-feedback between L and R delay lines for cascading delay effects
DAMPING
CC 22
High frequency reduction in delay repeats. Behavior varies per Delay Type.
DRY BLEND
CC 23
Amount of dry signal added to predelay output — recreates traditional predelay feel
PRE BLEND
CC 42
Amount of predelay reflections mixed in parallel with the reverb tank
Switches
Switch
MIDI CC
Positions
REVERB STRUCTURE
CC 32
Ultraplate / Cathedra / Spring / 78 Room / 78 Plate / 78 Hall / Prism / Gravity
DELAY STRUCTURE
CC 13
Standard / Reverse
DELAY TYPE
CC 16
Digital / BBD / Magnetic
HALF SPEED
CC 24
Off / On
Preamp
CC 5
Off / Volume Pedal / Tube / Transistor / Op-Amp
Preamp
CC 6
Pre + Dry / Pre / Feedback / Pre Tank / Post
Dynamics
CC 62
Off / Compressor / Comp Link / Swell / Diffusion / Limiter / Lim Link / Freeze
Dynamics
CC 63
Pre + Dry / Pre / Feedback / Pre Tank / Post
Pitch
CC 70
Off / Poly Chroma / Micro Shift / Lo-Fi
Pitch
CC 71
Pre + Dry / Pre / Feedback / Pre Tank / Post
Filter
CC 78
Off / Ladder / State Variable / Parametric
Filter
CC 79
Pre + Dry / Pre / Feedback / Pre Tank / Post
Mod
CC 86
Off / 79 Chorus / Vibrato / Vowel Mod / Tremolo / Hazy
Mod
CC 87
Pre + Dry / Pre / Feedback / Pre Tank / Post
Per-Mode Parameters
Ultraplate
Control
MIDI CC
Description
LO FREQ
CC 34
Low frequency tone control
HI FREQ
CC 35
High frequency tone control
MOD SPEED
CC 36
Speed of reverb modulation
MOD DEPTH
CC 37
Depth of reverb modulation
PITCH
CC 38
Pitch shift applied to reverb tail
PITCH MIX
CC 39
Blend of pitch-shifted reverb signal
DIFFUSION
CC 40
Density of early reflections
Cathedra
Control
MIDI CC
Description
LO FREQ
CC 34
Low frequency tone control
HI FREQ
CC 35
High frequency tone control
MOD SPEED
CC 36
Speed of reverb modulation
MOD DEPTH
CC 37
Depth of reverb modulation
PITCH
CC 38
Pitch shift applied to reverb tail
PITCH MIX
CC 39
Blend of pitch-shifted reverb signal
DIFFUSION
CC 40
Density of early reflections
Spring
Control
MIDI CC
Description
LO FREQ
CC 34
Low frequency tone control
HI FREQ
CC 35
High frequency tone control
78 Room
Control
MIDI CC
Description
BASS
CC 34
Bass decay time below crossover frequency
TREBLE
CC 35
Treble character of the reverb
CROSS
CC 36
Crossover frequency of EQ network (0-1700 Hz)
TANK MOD
CC 37
Modulation depth inside the reverb tank
DIFFUSION
CC 38
Density of early reflections
78 Plate
Control
MIDI CC
Description
BASS
CC 34
Bass decay time below crossover frequency
TREBLE
CC 35
Treble character of the reverb
CROSS
CC 36
Crossover frequency of EQ network (0-1700 Hz)
TANK MOD
CC 37
Modulation depth inside the reverb tank
DIFFUSION
CC 38
Density of early reflections
78 Hall
Control
MIDI CC
Description
BASS
CC 34
Bass decay time below crossover frequency
TREBLE
CC 35
Treble character of the reverb
CROSS
CC 36
Crossover frequency of EQ network (0-1700 Hz)
TANK MOD
CC 37
Modulation depth inside the reverb tank
DIFFUSION
CC 38
Density of early reflections. Set to Low for sparse mode.
Prism
Control
MIDI CC
Description
SIZE
CC 34
Size of the geometric room
DISPERSION
CC 35
Spread of reflections
DISTANCE
CC 36
Distance and reflectivity of the dual tank
LO CUT
CC 37
Low frequency cutoff
HI CUT
CC 38
High frequency cutoff
MOD SPEED
CC 39
Modulation speed
MOD DEPTH
CC 40
Modulation depth
MOD PHASE
CC 41
Phase offset between L/R modulation for stereo widening
Gravity
Control
MIDI CC
Description
TILT EQ
CC 34
Tilt EQ — tilts between low and high frequency emphasis
MOD SPEED
CC 35
Modulation speed
MOD DEPTH
CC 36
Modulation depth
MOD FDBK
CC 37
Modulation feedback amount
GAIN
CC 38
Gain control — crucial for taming explosive textures
MOD
CC 39
Additional modulation inside the reverb tank
Processing Block Parameters
Compressor
Control
MIDI CC
Description
THRESHOLD
CC 64
Compressor threshold level
RATIO
CC 65
Compression ratio
GAIN
CC 66
Makeup gain
ATTACK
CC 67
Attack time
RELEASE
CC 68
Release time
MIX
CC 69
Wet/dry mix for parallel compression
Comp Link
Control
MIDI CC
Description
THRESHOLD
CC 64
Compressor threshold level
RATIO
CC 65
Compression ratio
GAIN
CC 66
Makeup gain
ATTACK
CC 67
Attack time
RELEASE
CC 68
Release time
MIX
CC 69
Wet/dry mix
Swell
Control
MIDI CC
Description
ATTACK TIME
CC 64
Swell attack time
GAIN
CC 65
Swell gain
Diffusion
Control
MIDI CC
Description
DENSITY
CC 64
Density of multitap delays for smoothing
LOW PASS
CC 65
Low pass filter to soften highs
Limiter
Control
MIDI CC
Description
THRESHOLD
CC 64
Limiter threshold
GAIN
CC 65
Limiter gain
RELEASE
CC 66
Release time
Lim Link
Control
MIDI CC
Description
THRESHOLD
CC 64
Limiter threshold
GAIN
CC 65
Limiter gain
RELEASE
CC 66
Release time
Freeze
Control
MIDI CC
Description
FREEZE
CC 64
Freeze amount — initiates infinite sustain
GAIN
CC 65
Frozen signal gain
MIX
CC 66
Wet/dry mix of frozen signal
Processing Block Parameters
Poly Chroma
Control
MIDI CC
Description
PITCH
CC 72
Chromatic pitch shift amount
MIX
CC 73
Pitch shifter wet/dry mix
Micro Shift
Control
MIDI CC
Description
PITCH L
CC 72
Left channel detuning amount
PITCH R
CC 73
Right channel detuning amount
MIX
CC 74
Micro shift wet/dry mix
Lo-Fi
Control
MIDI CC
Description
PITCH L
CC 72
Left lo-fi pitch shift
PITCH R
CC 73
Right lo-fi pitch shift
MIX
CC 74
Lo-fi pitch wet/dry mix
Processing Block Parameters
Ladder
Control
MIDI CC
Description
FREQUENCY
CC 80
Filter cutoff frequency
RESONANCE
CC 81
Filter resonance
TOPOLOGY
CC 82
Filter topology — LP, BP, HP
SPREAD
CC 83
Offsets right channel filter frequency from left
State Variable
Control
MIDI CC
Description
FREQUENCY
CC 80
Filter cutoff frequency
RESONANCE
CC 81
Filter resonance
TOPOLOGY
CC 82
Filter topology — LP, BP, HP
SPREAD
CC 83
Offsets right channel filter frequency from left
Parametric
Control
MIDI CC
Description
FREQUENCY
CC 80
Center frequency
RESONANCE
CC 81
Q / bandwidth
TOPOLOGY
CC 82
Shelving type
GAIN
CC 83
Boost/cut amount (-10dB to +10dB)
Processing Block Parameters
79 Chorus
Control
MIDI CC
Description
SPEED
CC 88
Chorus modulation speed
DEPTH
CC 89
Chorus modulation depth
NOTE DIV
CC 90
Note division for tempo sync
Vibrato
Control
MIDI CC
Description
SPEED
CC 88
Vibrato speed
DEPTH
CC 89
Vibrato depth
NOTE DIV
CC 90
Note division for tempo sync
Vowel Mod
Control
MIDI CC
Description
SPEED
CC 88
Modulation speed between vowels
VOWEL A
CC 89
First vowel selection
VOWEL B
CC 90
Second vowel selection
RESONANCE
CC 91
Filter resonance intensity
MANUAL
CC 92
Manual vowel position (when Speed is at minimum)
NOTE DIV
CC 93
Note division for tempo sync
Tremolo
Control
MIDI CC
Description
SPEED
CC 88
Tremolo speed
WAVESHAPE
CC 89
Tremolo waveshape
MIX
CC 90
Tremolo wet/dry mix
NOTE DIV
CC 91
Note division for tempo sync
SPREAD
CC 92
Stereo offset between L/R tremolo
VOICE
CC 93
Opto (classic volume pulsing) or Harmonic (filtered alternating)
Hazy
Control
MIDI CC
Description
DECIMATE
CC 88
Sample rate reduction for lo-fi character
WARBLE
CC 89
Tape-like pitch wobble
AGE
CC 90
Simulates aging tape degradation
LOWS
CC 91
Low frequency content
HIGHS
CC 92
High frequency content
MIX
CC 93
Hazy effect wet/dry mix
Footswitches
BYPASS — bypass on CC 14
TUNER — bypass on CC 117
HOLD MODIFIER — bypass on CC 118
Special MIDI Functions
Expression — CC 4
Bypass — CC 14. When on, the effect is bypassed (dry signal only). When off, the effect is engaged. Per Meris spec: 0–63 = FX bypass, 64–127 = FX enabled.
Dry Trim — CC 2. Fine-tune dry signal level relative to mix
Wet Trim — CC 3. Fine-tune wet signal level relative to mix
Left Note Div — CC 17. Left delay line note subdivision. Off = quarter notes matching blinking Tap LED.
Right Note Div — CC 18. Right delay line note subdivision. Off = quarter notes matching blinking Tap LED.
Gate Attack — CC 43. Gate attack time — shapes the onset of gated reverb effects
Gate Hold — CC 44. Gate hold time — how long the gate stays open
Gate Decay — CC 45. Gate decay time — how quickly the gated reverb fades
Preamp Gain — CC 7. Gain/volume level for the preamp section. Tube: mid boost gain. Transistor: high frequency emphasis. Op-Amp: broadband boost.
Preamp Balance — CC 8. Balance parameter for the preamp section
Preamp Level — CC 11. Output level of the preamp effect
MIDI Clock — CC 28. Controls how this preset responds to incoming MIDI Beat Clock. 0-42 = Use Global; 43-85 = Force Listen; 86-127 = Force Ignore.
Toggle Tuner — CC 117. Activates the chromatic tuner. Send value 127 to engage Tuner mode.
Hold Modifier — CC 118. Triggers the Hold Modifier function. Send 127 to press, then send 0 to release. Always send a release (0) after every press.
Hardware Presets
The Mercury X has 99 hardware preset slots. Nitelite can save your current settings to a slot and recall slots via MIDI program change.