Quick Start
Introduction
Thank you for choosing the Sprout Modulation by Klowra. Sprout Modulation is a stereo modulation pedal offering nine distinct effects—from classic analog-inspired warmth to realistic physical modeling and imaginative, forward-thinking textures. Powered by high-quality algorithms and open parameter architecture, it delivers a responsive, inspiring modulation experience for creative exploration.
Equipped with the Bloom Infinity Series-exclusive Ramp function and Tap Tempo, Sprout Modulation offers dynamic, expressive control. Paired with an expression pedal or external footswitch, it allows for expressive and dynamic tone shaping. With Analog Dry-Through, selectable True or Buffered Bypass, and multiple stereo output modes, Sprout ensures clean signal integrity and flexibility across a wide range of setups.
Knobs and Switches
RATE
Sets the speed of the LFO (Low-Frequency Oscillator), determining how fast the modulation cycles.
DEPTH
Controls the intensity of the LFO’s modulation. Higher values produce more dramatic, sweeping effects.
MIX
Controls the mix between the dry and wet signals. At the minimum, it outputs full dry signal; at the maximum, it outputs full wet signal with no dry signal. A 50/50 mix occurs around 2 o’clock on the knob.
You can choose between two mix modes - Constant Power Mixer and Linear Superposition Mixer - depending on your tonal preference. For details on how to switch modes, refer to the *Power-Up Modes* section.
MODULATION SELECT
VIBE – Inspired by classic LDR/transistor circuits, upgraded with sweep range, MIX, and feedback control. Turning the TEXTURE knob clockwise increases feedback and enhances modulation intensity, striking a balance between vintage character and modern depth.
CHORUS – Digitally recreates the nuances of vintage BBD-based analog chorus, including clock drift, compression, and textured LFO shaping. TEXTURE increases delay time (clockwise), enhancing spatial width and adding 3D depth to the sound.
MULTI-CH – A triple-voice chorus with independently modulated layers (timing, depth, and speed). TEXTURE expands both delay time and stereo spread. Unlike traditional choruses, this mode emphasizes organic movement over overt modulation cycles.
FLANGER – Revives saturated BBD-style flanging with aggressive feedback. Turning TEXTURE right increases feedback for a range of tones—from warm, tape-like warble to sharp, metallic sweeps.
FILTER – Modeled after ladder-style VCFs found in analog synths. Integrates rich resonance and saturation with a virtual modulation stage, offering deep, expressive tonal shaping.
PHASER – A six-stage JFET phaser designed to emulate vintage tones. The TEXTURE knob adjusts feedback intensity—turn it clockwise for heightened resonance and shifting textures, from smooth to harmonically rich.
ROTARY – Simulates the movement and tone of a rotary speaker, reproducing the rotating horn (high frequencies) and drum (low frequencies) to deliver immersive motion and depth.
TREMOLO – A clean, triangle-wave tremolo designed for smooth modulation and precise rhythmic control.
RING – A self-modulating digital ring modulator that evolves in real time, generating futuristic, sci-fi-inspired tones.
TEXTURE
Adjusts the texture of the LFO reflections. Turning the control to the right softens the early reflections and produces a smooth onset of the modulation.
TONE
Adjust the high frequencies within the wet signal，with the darken BRIGHT at minimum and brighten BRIGHT at maximum.
Footswitch
Control ON/OFF. Press&Hold to trigger Tap tempo or Ramp.
Refer to the *Tap Tempo* or *Ramp* section for details.
The LED Button
Lit when active, pressed or in combination with other knobs to adjust various functions and Hidden Parameters.
Hidden Parameters
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Rhythm
Tap Tempo supports three rhythmic subdivisions. Select the desired subdivision by rotating the knob:
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Quarter-note: Turn the knob fully counterclockwise (leftmost position).
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Eighth-note: Turn the knob 12 o’clock position.
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Eighth-note triplet: Set the knob to the fully clockwise (rightmost position).
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RampATK
Controls the attack time of the Ramp modulation, determining how quickly the fade reaches the Snap-Set. A shorter attack time results in a quicker transition to the Snap-Set, while a longer attack time creates a smoother, more gradual fade.
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RampRLS
Controls the release time of the Ramp modulation, determining how gradually the transition fades back to the Panel-Set. A shorter release time results in a quicker return to the Panel-Set, while a longer release time provides a more drawn-out, fluid return to the Panel-Set.
For adjustments to Hidden Parameters, please refer to the *Description of the LED Button* section.
Rear Panel I/O
9V DC
Connect to a 9V DC power supply with a center-negative polarity and a minimum current rating of 250mA.
Note: If the power supply is insufficient, the pedal may malfunction.
IN L (Mono)
1/4" mono (TS) unbalanced left input for mono setups.
IN R (Stereo)
1/4" mono (TS) unbalanced right input for mono setups.
OUT L (Mono)
1/4" mono (TS) unbalanced left output for mono setups.
OUT R (Stereo)
1/4" mono (TS) unbalanced right output for stereo setups.
CTRL
1/4" stereo (TRS) balanced input for connecting an expression pedal or external footswitch.
Note: Please refer to the *External Control* section for information on how connection is recognized.
Signal Path
Configuring the In/Out Settings
1-in, 1-out
Mono input with mono output. The dry and wet signals are mixed together in the mono output.
1-in, 2-out
For the IN L, the dry and the wet sounds are mixed when stereo output.
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Dry/Wet Separation output : For the IN R, OUT R carries the dry signal; OUT L carries the wet signal.
*Dry/Wet Separation outputs allows a guitar signal to be split into two distinct paths: one carrying the unaffected (dry) sound, and the other carrying the processed (wet) effect signal. This configuration offers a range of creative and practical applications, particularly useful for live performances, studio setups, and
advanced signal routing. *
2-in, 2-out
For the IN L&R , the dry signal and wet signal sounds are mixed when OUT L&R.
Description of the LED Button
The LED Button is the heart of the Sprout.
You can determine the current operating status of the Sprout by observing the color of the LED button. The LED button can be pressed briefly or in combination with other knobs to adjust various functions or parameters.
Learning to interpret the LED colors and understanding the different ways the button can be pressed are essential for familiarizing yourself with the Sprout’s operation.
What the LED Colors Mean
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White : Tap tempo function active;
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Blue : Tap tempo is actively being triggered.
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Orange : Ramp function active;
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Violet : Ramp is actively being triggered.
What the Button Can Adjust
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Toggle the Tap Tempo or Ramp
Press once to switch between Tap Tempo and Ramp.
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Save Snap-Set
Press & Hold to save the current parameter settings as Snap-Set.
The LED blinks violet to confirm.
Press & Hold while rotating the knob above the hidden parameters.
Successful adjustment is indicated by the LED blinking yellow.
Tap Tempo
*Press & Hold the footswitch while the LED is white, until the LED turns blue, indicating the entry into Tap Tempo.*
Tap Tempo allows you to set the delay time (TIME) in real time by tapping the footswitch in rhythm with your music. This feature synchronizes the delay repeats with your playing, delivering a precise, groove-locked response that enhances rhythmic clarity and feel.
You can enter Tap Tempo mode directly from the main operation. After tapping, the system automatically exits the mode if no input is detected within 5 seconds.
- How to use Tap Tempo
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Press and hold the footswitch while the LED is white.
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Wait for the LED to turn blue, indicating that Tap Tempo mode is active.
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Tap the footswitch repeatedly in time with your desired tempo. Each tap adjusts the delay time to match the BPM.
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After 5 seconds of inactivity, the LED will return to white, and the pedal will automatically exit Tap Tempo mode.
Rhythm Subdivisions:
The Tap Tempo supports multiple rhythmic divisions for versatile delay timing:
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Quarter-note: Turn the knob fully counterclockwise (leftmost position).
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Eighth-note: Turn the knob 12 o’clock position.
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Eighth-note triplet: Set the knob to the fully clockwise (rightmost position).
These options let you tailor the LFO timing—from tight, locked-in pulses to syncopated, ambient movement.
For Rhythm adjustment, please refer to *Description of the LED Button* section.
*Press and hold the footswitch while the LED is orange. When the LED turns violet, you’ve entered Ramp.*
Ramp allows for smooth, dynamic transitions between two sets of parameters:
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Panel-Set–Your current front-panel parameter settings.
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Snap-Set–A saved set of parameters stored using the LED button.
This feature creates expressive, evolving fades that add depth, movement, and emotion to your sound. The speed and character of the transition are defined by two parameters:
RampATK (Attack Time):
Controls how quickly the effect fades from the Panel-Set to the Snap-Set.
- A shorter attack gives a fast, sharp transition.
- A longer attack creates a smoother, more gradual fade.
RampRLS (Release Time):
Controls how quickly the sound returns from the Snap-Set to the Panel-Set.
- A shorter release results in a quick recovery.
- A longer release provides a more drawn-out, fluid return.
Ramp Modes
Ramp supports two switching modes - Momentary and Latched—giving you flexibility to match your performance style.
Press&Hold the footswitch to fade into the Snap-Set over RampATK time.Release the footswitch to return to the Panel-Set over RampRLS time.
Press once to transition to the Snap-Set (RampATK), and press again to return to the Panel-Set (RampRLS).
To select between Momentary and Latched modes, see the *Power-Up Modes* section.
Power-Up Modes
How To enter Power-Up Modes:
Press & hold the footswitch while powering on the pedal. A flashing LED indicates successful entry. Once your settings are configured, press the footswitch again to exit Power-Up Modes.
In this mode, you can adjust the following settings:
Bypass Modes
Switch between modes by short-press the LED button.
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True Bypass
The signal is routed directly through the pedal with no buffering or coloration.
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Green LED flashes to indicate True Bypass mode.
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Buffered Bypass(Trails on)
The signal is routed through a buffer with Analog Dry Through, allowing delay trails to continue after the effect is bypassed.
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Red LED flashes to indicate Buffered Bypass mode.
Ramp Lock
Select by rotating the DEPTH knob.
- Turn fully left for Momentary (LED flashes yellow 3x).
- Turn fully right for Latched ( LED flashes blue 3x).
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Momentary:
Hold the footswitch to transition to Snap-Set over RampATK time. Release to return to the current set over RampRLS time.
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Latched:
The first press transitions to Snap-Set over RampATK time. The second press returns to the current set over RampRLS time.
MIX Modes
Select MIX Mode by rotating the MIX knob.
- Turning it fully left selects the Constant Power Mixer (LED yellow flashes 3x).
- Turning it fully right selects the Linear Superposition Mixer (LED blue flashes 3x).
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Constant Power Mixer
In this mode, the wet and dry signals are mixed in a way that maintains consistent power across the mix. This means that the volume of the wet signal will increase or decrease in relation to the dry signal to maintain a balanced overall sound, with no excessive gain or loss when blending the signals.
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Linear Superposition Mixer
This mode blends the dry and wet signals using a linear approach, meaning the signals are simply added together at equal strength, without adjusting for perceived loudness. This results in a more direct, unaltered blend of both signals, which may introduce some dynamic changes depending on the level of the wet signal.
LED Brightness
Adjust by rotating the TONE knob.
- Turn fully left for dimmest.
- Turn fully right for brightest.
Connection & Activation
When connecting an external TS/TRS footswitch or expression pedal, the LED indicator will flash red. Trigger the footswitch or pedal repeatedly during this state.
Once the connection is successfully recognized, the Sprout will return to normal operation.
Note: If the External Control is not fully activated, it may result in limited functionality.
External Footswitch Compatibility
When connecting an external TS/TRS footswitch, there are two specific functional settings, depending on the color of the LED indicator:
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LED White - The current footswitch-specific function is Freeze/Infinite.
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TS Footswitch : Momentary triggers Ramp.
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TRS Footswitch:
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Tip Position: Momentary triggers Ramp.
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Ring Position: Momentary triggers Tap Tempo.
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LED Orange - The current footswitch-specific function is Ramp
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TS/RS Footswitch: Momentary triggers Tap Tempo.
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TRS Footswitch:
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Tip Position: Momentary triggers Ramp.
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Ring Position: Momentary triggers Tap Tempo.
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Expression Pedal Compatibility
When an expression pedal is connected, it takes direct control over the Ramp by blending between the Panel-Set and Snap-Set. In this mode:
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The Ramp ATK and Ramp RLS parameters are disabled.
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Ramp cannot be triggered by Press&Hold the footswitch.
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The expression pedal locks Sprout into LED White (Tap Tempo active), and mode switching to LED Orange (Ramp active) is disabled.
How do I update my Klowra pedal?
1/ Download the latest firmware update file for your model from the relevant model page.
2/ Connect the Klowra pedal to your computer using the USB-C data cable.
3/ Hold down footswitch&the LED button while powering on, the LED flashing red.
4/ Open the firmware update file. Please avoid opening multiple installers at the same time, as this may cause detection issues. Click Update to begin installing the firmware.
5/ After the successful update, the LED turns off. Restart the pedal and enjoy!
STILL UNABLE TO CONNECT KLOWRA PEDAL?
If reconnecting the pedal or restarting the software doesn't help, check the following:
1. Verify that the USB data cable is securely connected to both the pedal and your computer, and try using a different USB port if necessary.
2. Replace the USB data cable with a known-good one and attempt to reconnect the pedal.
IF THE PROBLEM CONTINUES, PLEASE FOLLOW THESE STEPS:
1. Close the update software, and then follow the steps below in order.
2. Connect your klowra pedal to your computer with a USB data cable (not included).
3. Relaunch the update software.
4. Power on the pedal while holding both the footswitch and the LED button.
5. The LED button wil flash red. Wait a moment, then click "Update" to begin the firmware process.
Inputs | 2 x 1/4"TS Instrument jacks |
Input Impedance | 500k Ohm |
A/D & D/A | 24 Bit 44.1K Hz |
Power Source | 9V DC power supply required |
External Control | TS/TRS Momentary footswitch, or TRS expression pedal |
Hardware Interface | USB-C |
Outputs | 2 x 1/4"TS Instrument jacks |
Output Impedance | 100 Ohm |
Max Input Level | +10 dBu |
Current Draw | 250mA |
Bypass Mode | Switchable: True Bypass, Buffered Bypass(AnalogDry-Through) |
Dimensions | 54.7mm H x 124.8mm D x 69.2mm W(2.0"H x 4.9"D x 2.7"W) |