The Nimbus Special Edition takes the liquid and deep reverb of the Nimbus and adds several new features that expand its capabilities greatly:

Assignable expression pedal input:

– "Size" controls the Room Size, Bass, and Treble simultaneously - take the Nimbus SE from a small, subtle room sound, up to infinite-hold pads with expression control.

– "In Lvl" controls the level of signal sent into the reverb path. Use this to reverberate certain parts of a passage, or to build up ambient chords in the reverb and play cleanly on top of them.


Expression stomp takes the place of the expression pedal (fully on or off) when no expression is plugged in. The LED changes from blue to magenta when the Exp stomp switch is active.

– When assigned to "Size," you can set up a second reverb sound using the Exp knob, and toggle between them, giving you two preset sounds at a time. If you set the Exp knob all the way up, the Nimbus SE will go to infinite reverb times, allowing you to hold a note infinitely until you stomp Exp again.

– When assigned to "In Lvl," you can click the Exp stomp switch on to let signal into the reverb, then click it off so that new notes play cleanly on top of the sustained note.

– When Assigned to "In Lvl," at anything other than infinite reverb times, you can use the Exp stomp switch as a silent, "trails" bypass - the last notes played before bypassing will ring out rather than being cut off as in true bypass. You still have true bypass available with the standard bypass stomp switch, giving you the best of both worlds.


With an expression pedal connected, the Exp knob acts as a maximum value limiter for the expression pedal, and the Exp switch acts as an on/off for the expression pedal.


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Room Size: Controls the size of the reverberating space, continuously variable from small practice rooms to massive concert halls with long ambient decay, and when the filter is defeated, approximately infinite decay time is possible.

Bass: Controls the level of low frequencies within the reverb’s feedback path. Typical reverbs can become muddy when applied to bass – by using this control to filter low frequencies from the reverb path, the tightness, definition, and low end of the instrument’s natural sound can be maintained even with huge reverbs. The control turns off at minimum, to allow for full-range reverb if desired.

Treble: Controls the level of high frequencies within the reverb’s feedback path. Turning this down will create darker tones. Since the Bass and Treble controls are inside the reverb feedback path, and not simply placed before or after the effect, each repeat will become progressively more filtered, creating shifting timbres over time as the reverb decays.

Turning Room Size, Bass, and Treble all the way clockwise will set the Nimbus into Infinite mode.

Clean: Controls the volume of the clean signal, which remains analog throughout the signal path.

Reverb: Controls the volume of the reverb signal.

The two volume controls are extremely flexible: everything from a barely-perceptible amount of reverb, all the way to 100% wet can be achieved.

Exp: If an expression pedal is attached, the Exp knob limits the maximum expression value, allowing you to set up a large or small window of control coming from the expression pedal.

With no expression pedal attached, the Exp knob sets the value selected for either "Size" or "In Lvl" when the Exp stomp switch is active (LED changes to magenta). For example, set up a basic reverb sound to your taste with the Room Size, Bass, and Treble knobs. Now with the Exp knob at maximum, activating the Exp switch will set the Room Size, Bass, and Treble all to maximum, creating a nearly infinite, cavernous sound. Setting Exp to a medium value will add a medium amount to all three upper knobs, allowing you to set up a second reverb sound and switch to it mid-performance.


Low-noise, low-distortion active components chosen for excellent audio fidelity.

Measures 4.7″ x 2.5″ (12cm x 6.3cm). 

Runs on industry-standard 9 volt DC center-negative power supply. 85mA current draw.

Relay-based true bypass.

All jacks are located at the top of the pedal to save pedalboard space.

Learn more about the construction of IE pedals here.

Expression jack: Because of its Exp knob, which acts as an attenuator on the maximum expression value, just about any expression pedal can be used.


Thanks to Prymaxe for this demo.

Thanks to Justin Goodman for this video.