Meris Hedra

While Meris may be one of the new kids on the block, their pedals have garnered much attention and acclaim. After working with the Hedra, it is easy to see why. For many horn players, the first pedal they seek out involves changing or adding pitches. Because of that, any new octave, pitch shifter, or harmonizer pedal gets the HornFX team excited. That was no different for the Hedra. This new harmonizer is truly excellent. Boasting gorgeous tone, deep customization capabilities, and exceptional harmonic capabilities, the Hedra is one of the finest Harmonizer pedals we have reviewed.

External Control: MIDI/EXP/TAP
Cost: $$

HornFX Review

Interface:  3.5/5
The Hedra packs a lot of functionality into a small package. This usually means that there are going to be some difficult or confusing controls on the face of the pedal. That is not the case with the Hedra (At least initially). Unlike other complex harmonizers, the Hedra is easy to understand right out of the gate. Its intuitive and simplistic controls make dialing in a wide range of voicings and harmonies easy to manage without doing much practice or reading of the manual. There is no mistaking what the knobs do, or how they affect the resulting sound, until you dig deeper. While these basic controls are simple, the secondary controls (each knob has a secondary function) can start to become difficult to keep track of. This can become a bit of a challenge when trying to change from one patch to another. If you were to switch from a pitch-gliding synthetic sound to a simple and organic harmony, it would certainly take a while, all precious seconds when performing live to be sure. With that said, all of these potential difficulties can be avoided by using MIDI control, which unlocks the ability to use presets, expression, and more. While it has its difficulties, this pedal does an exceptional job of making a wide range of chords and voicings easy to achieve, and with the use of MIDI, the Hedra becomes one of the most functional and useful harmonizer pedals available.

Versatility: 3.5/5
The Hedra is a harmonizer through and through. Within that categorization, it is extremely versatile. The user can dial in 3 additional pitches to harmonize in simple or complex keys. There are a wide and unique range of scales to define your voicings, including the basic major and minor, but also including harmonic and melodic minor, eastern pentatonic, and double harmonic. It can produce pitches at any interval in the range from an octave below the input note to an octave above, as well as add a pitch two octaves below or two octaves above. While its pure harmonic capabilities can match up with even the most extreme harmonizers, it has less to offer in terms of secondary functions. While pedals like the Pitchfactor can produce wild textures, arpeggios and more, the Hedra sticks mostly to harmony. This can be a welcome reality for some, as the clutter of multiple effects within one pedal will not distract or confuse the user. Even still, the Hedra has some incredibly cool secondary features including pitch delays, pitch correction, detune, and portamento! As a pure harmonizer, this pedal can stack up with any of its competitors, and its secondary functions make its harmonic versatility that much more enticing.

Tonal reproduction: 5/5
This pedal has the best tonal reproduction we have seen from any pitch shifting pedal.

Tracking speed: 4.5/5
This pedal tracks extremely well. It can keep up to fast lines with ease. Not only does it track with the best of them, but its reproduction of articulation is quite good. It can reproduce your playing with surprising accuracy when you transpose yourself or add more pitches to harmonize with. This is simply one of the most organic sounding pitch-manipulation pedals we have ever used.

Complexity: High

Complexity: High

Live application: 3.5/5
This is an incredible pedal. It is capable of so much and sounds absolutely fantastic. However, it may not be the right pedal for all who are searching for a harmonizer. If you are able to control the Hedra with MIDI in your setup, then this pedal would receive a near perfect score. MIDI control is what makes this pedal truly great on stage. If you do not have MIDI control, it can be a difficult beast to master. The knobs turn incredibly smoothly, and have many intervals or keys to choose from along its circumference. That, paired with the small text surrounding the knobs, can make for some extreme difficulty when needing to dial in precise voicings. Even in full light, with no pressure and no time limit, it can be a challenge to dial in each knob correctly. There is almost no room for error and the knobs seem almost eager to keep turning. The secondary functions are surprisingly easy to access (once you memorize them), but knob position can be quite confusing when you have to keep track of a second setting for each knob. These challenges are natural for a pedal of this size with so much functionality, but with the implementation of MIDI control, these challenges can completely disappear.

InterfaceVersatilityTonal ReproductionTracking SpeedLive ApplicationTotal Score

Product Information


  • Premium quality 24 bit A/D and D/A

  • 32 Bit floating point DSP hardware

  • Premium low noise Analog signal path throughout

  • Digitally controlled Analog Dry path for wet/dry mix

  • Analog Devices JFET input circuitry

  • Selectable True Bypass (Relay) or Analog Buffered Bypass

  • Durable transparent coated brushed aluminum

  • Current draw < 150 mA

  • Dimensions – 4.25″ wide, 4.5″ long, 2″ tall 

All product info from the Meris website



3-Voice Rhythmic Pitch Shifter

  • Selectable Pitch Correction Types to ReVoice your Melodies in RealTime

  • Individual Controls for Pitch and Time Offset for each Voice (3 Voices Total)

  • Micro Tune control creates gentle chorus-like detuning, classic studio fattening, and extreme warping

  • Chromatic or Key Driven Harmony with Selectable Scale Types

  • 4 Delay Configurations with unique Feedback Routing (520 mS max delay time)

  • Unique Keyboard Control putting a Live Quartet Under your Fingertips

  • Our Original Glide Mode slides between pitches at the speed you choose

  • Choice to sweep through Intervals smoothly or hard step for dramatic pitch effects

  • Switchable Half Speed and Auto Swell for advanced textures

  • Digitally controlled Analog mix control

  • Stereo input and output

  • Switchable input / output headroom level for Guitar or Synth / Line level

  • Expression pedal control over all parameters simultaneously

  • Presets available via external 4-Preset switch or MIDI

  • MIDI in/out over TRS via the EXP jack

  • External Tap Tempo over TRS

  • MIDI beat clock synchronization

  • Premium analog signal path and 24-bit AD/DA w/32 bit floating point DSP

  • Premium Analog Devices JFET input section

  • Color – raw brushed aluminum with clear coat

  • Designed and built in Los Angeles, California U.S.A.