The Electro-Harmonix Mod 11 is a compact digital modulation pedal that puts eleven different modulation effects, "from classic to exotic," in one box, along with tap tempo and a mode system that adds variations to each effect type1. Released in 2019, it is the third pedal in EHX's mini-series of feature-packed compact pedals, following the Canyon Delay and the Oceans 11 Reverb, and it follows the same idea those two established: eleven distinct variations chosen from a rotary switch234.
For a player, that means one small pedal covers tremolo, harmonic tremolo, vibrato, Univibe-style sounds, rotary speaker simulation, flanging, phasing, pitch modulation and synth-style modulated filters, instead of filling a pedalboard with individual units. Guitar World's Trevor Curwen described the range as including "Fender amp-style tremolo, a Small Stone-like phaser and a flanger that channels some of the textures of an Electric Mistress"4.
Eleven modulation effects in one compact pedal
The Mod 11 is hosted in EHX's regular compact case, which the maker describes as compact and rugged13. An eleven-position rotary switch on the panel, the MODULATION TYPE knob, selects which of the eleven modulation types is active1. Each type then has two or three modes, selected with the MODE button, that modify the behavior of that modulation type1.
The effect types named in the maker's documentation are:
| Type | What it does |
|---|---|
| TREM | Tremolo modulates your signal's volume. Selectable modes allow your playing envelope to control modulation rate or depth1 |
| HARM | Harmonic tremolo. The signal is split into high and low frequency bands and modulated between the two, with envelope control options1 |
| VIBR | Vibrato modulates your instrument's pitch, with envelope control options1 |
| UNI | Pays homage to the classic Univibe, with "Chorus" and "Vibrato" modes plus added overdrive1 |
| ROTARY | Rotary speaker cabinet simulation, with overdrive plus envelope control over rotation speed1 |
| FLANGE, TZF, PHASE | Flanger, through-zero flanger and phaser types; the VOLUME/COLOR knob sets feedback amount on these1 |
| PITCH | Pitch modulation; the VOLUME/COLOR knob sets the center pitch shift the modulation happens around1 |
| FILT | Modulated filter effects like those on classic analog synths: Low Pass, High Pass and Band Pass, with multiple LFO shapes including a Q-Tron style envelope follower1 |
The controls are shared across all eleven types:
- MODULATION TYPE knob: an eleven-position rotary switch that selects the active modulation type1
- RATE knob: sets the modulation speed. In some mod types, turning this knob to minimum enters Filter Matrix Mode1
- DEPTH knob: for most effects it sets depth or intensity; for the Rotary effect it sets the balance between the rotating drum and horn signals1
- VOLUME/COLOR knob: for the first six modulation types this is simply a volume knob. For FLANGE, TZF and PHASE it sets the amount of feedback, which increases the resonance and emphasis of the effect. For PITCH it sets the center pitch shift, and for FILT it sets the resonance1
- MODE button: cycles through the available modes of the active modulation type1
- FOOTSWITCH: toggles the pedal between bypass and effect modes1
Filter Matrix Mode
Filter Matrix Mode is a special setting reached by turning the RATE knob to its minimum position in some modulation types1. Instead of a moving sweep, the filter freezes in place, a behavior borrowed from classic EHX flanger designs. It is one of the features that pushes the pedal beyond standard chorus and tremolo territory.
Tap tempo and connections
The Mod 11 features tap tempo controllable via the built-in footswitch or an external one1. The TAP IN jack accepts an external momentary footswitch so you can tap in a tempo to control the modulation speed1. Connections are a standard 1/4" input, a standard 1/4" output, and the Tap input4.
The Mod 11 is mono and has no MIDI. Delicious Audio's multi-modulation buying guide flagged both limits when comparing compact mod pedals, so players who need stereo outputs or preset control over MIDI will want a larger unit7.
Power
The Mod 11 runs on the included EHX 9.6DC200mA power supply, a 9.6V DC adapter rated at 200mA15. The pedal's own current draw is 150mA1. There is no battery option: Guitar World's review noted that none of EHX's compact nine-volt pedals from this line support battery power, but they do include an adapter as part of the package4.
What reviewers said
Guitar World's Trevor Curwen reviewed the Mod 11 alongside the Nano Operation Overlord and Bass9, and found the effect set drew on EHX's own heritage, with the tremolo, phaser and flanger referencing Fender amps, the Small Stone and the Electric Mistress respectively4. At launch it carried a US street price of $151.00, and £134 in the UK54.
In a 2025 review on guitar.com, Josh Gardner compared the two directly, writing that the Mod 11 "sounds nowhere near as good as the Walrus but it's still pretty good and has loads of sonic options"8. Gearnews' 2025 budget-effects roundup took a similar position, acknowledging the Mod 11 "might not be stereo" while still rating it as a strong value among affordable modulation pedals9.
Where it sits in the EHX range
The Mod 11 is part of the same compact family as the Canyon Delay and Oceans 11 Reverb, all built around a rotary switch of eleven variations24. Players after a single dedicated effect rather than a multi-modulation box can look at EHX's individual chorus and flanger pedals, such as the Neo Clone, the Small Clone Chorus, the Stereo Electric Mistress or the Stereo Clone Theory, or browse the wider world of chorus pedals and multi-effects pedals.
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Questions
Is the EHX Mod 11 stereo?
No. The Mod 11 has a single quarter-inch input and a single quarter-inch output, so it is a mono pedal. Reviewers and buying guides have noted the lack of stereo as one of its limits compared with larger multi-modulation units.
Does the Mod 11 have MIDI?
No. The Mod 11 has no MIDI connection. You select effects with an eleven-position rotary knob on the panel and switch modes with a button, so presets and program changes are not available.
Can the Mod 11 run on a battery?
No. The Mod 11 does not support battery power and runs from the included EHX 9.6DC200mA adapter, which supplies 9.6V DC at up to 200mA. The pedal itself draws 150mA.
Is the Mod 11 true bypass?
No. Electro-Harmonix lists the Mod 11 as buffered bypass. When the pedal is off, your signal passes through a buffer rather than being hard-wired straight through as with true bypass.
What is Filter Matrix Mode on the Mod 11?
Filter Matrix Mode is a special setting reached by turning the RATE knob to its minimum position in some modulation types. It stops the sweep and freezes the filter, an effect borrowed from classic Electro-Harmonix flangers.
Can I use an external tap tempo switch with the Mod 11?
Yes. The Mod 11 has a TAP IN quarter-inch jack. Connect an external momentary footswitch to it and tap in a tempo to set the modulation speed, or use the built-in footswitch for the same purpose.
Sources (9)
- MOD 11 | Modulation Pedal - Electro-Harmonix, Electro-Harmonix (ehx.com)
- Electro-Harmonix crams 11 modulation effects into one pedal with the Mod 11 Modulator, Guitar World, 2019-08-15
- Electro-Harmonix MOD 11 Modulator, Delicious Audio, 2020-01-21
- Electro-Harmonix Mod 11, Nano Operation Overlord and Bass9 Bass Machine, Guitar World, 2020-03-20
- Electro-Harmonix Unveils The Mod 11 Modulator Pedal, Bass Gear Magazine, 2019-08-14
- Blurst! | Modulated Filter - Electro-Harmonix, Electro-Harmonix (ehx.com)
- Best Pedals For Synths: Multi-Modulation Stompboxes, Reviewed, Delicious Audio, 2023-11-02
- Walrus Mako M1 MKII review, guitar.com, 2025-09-22
- The Best Budget Effects Pedals for Electronic Music Production, gearnews.com, 2025-07-02
