The Electro-Harmonix Holy Grail is a digital reverb pedal that Vintage Guitar was already reviewing in June 2002, describing "their new digital Holy Grail Reverb pedal"1. Its calling card was simplicity: a small box with a handful of reverb types, including a hall setting that Electro-Harmonix describes on the Holy Grail Nano page as "smooth hall reverb tailored to the guitar"2. The pedal later appeared in several versions, from the compact Nano to the four-mode Max.
The hall mode is the reason many players keep one on the board. It is a digital emulation of a large room or hall, sized for guitar rather than a full mix, and it is the setting most reviewers single out as the pedal's strength341.
The Holy Grail family: original, Nano, Neo, Plus and Max
The original Holy Grail set the template: a compact digital reverb with three modes, spring, hall and flerb3. From there the family grew in two directions, smaller and more fully featured.
| Version | Modes | Notes |
|---|---|---|
| Holy Grail (original) | Spring, Hall, Flerb | The pedal the family is built on36 |
| Holy Grail Nano | Spring, Hall, Flerb | Compact version of the original28 |
| Holy Grail Neo | Spring, Hall, Plate | Update to the original, in EHX's die-cast nano chassis910 |
| Holy Grail Plus | Spring, Hall, Room, Flerb | Adds a Room mode; discontinued 202211 |
| Holy Grail Max | Spring, Hall, Plate, Reverse | Four modes, including reverse reverb512 |
The Nano is the direct compact sibling. JHS Pedals' reviewer notes the reverb is "available in the larger, original version or in a nano version"4, and Gearnews describes the Nano as "a compact and straightforward reverb pedal designed to deliver classic ambience"7. Both carry the same three modes, so the choice between them comes down to enclosure size rather than sound options.
The Neo, announced in 2015, is described by EHX as "an update to our wildly popular compact digital reverb, the Holy Grail"98. It swaps Flerb for a Plate algorithm, keeping Spring and Hall, and Guitar.com noted it is housed in EHX's die-cast nano chassis10. The Plus kept the original three modes and added a Room reverb, with its REVERB switch choosing between SPRING, HALL, ROOM or FLERB11. The Max went further, with Guitar World reporting in February 2014 that "the new pedal shares the Holy Grail's classic Spring and spatial Hall reverbs" and adds Plate and Reverse12.
The Holy Grail Plus is marked discontinued 2022 on Electro-Harmonix's product page11. Players wanting the Room mode new will need to look at other EHX reverbs.
Reverb modes across the versions
Every version of the Holy Grail is digital, from the original onward219115. That matters for the Spring mode in particular: as Gearnews points out, the Nano "doesn't include an actual analog spring reverb," so the spring sound is an emulation rather than a real spring tank7.
- Spring: a digital emulation of spring reverb. MusicRadar's Alex Lynham called the original's spring "a passable recreation of a spring reverb"3.
- Hall: the mode this page is named for. EHX describes it as smooth hall reverb tailored to the guitar2.
- Flerb: EHX says "Flerb combines flanging with spatial reverb for a unique ethereal sound"2. MusicRadar lists it as the pedal's unique feature, mixing reverb with flange3.
- Room: added on the Plus, described by EHX as a graceful room reverb11.
- Plate and Reverse: added on the Neo and Max respectively95.
The controls stay simple across the compact versions. The Nano has a single Reverb knob and a three-way switch to toggle between Spring, Hall and Flerb7, and the Plus uses one REVERB switch for its four modes11. In a Strymon pedalboard feature, player Mike Gavrailoff described his Nano Holy Grail's three options, calling Flerb "a modulated style" reverb8.
What reviewers said about the hall and Flerb settings
The hall mode gets the strongest praise. MusicRadar's reviewer wrote that "it's the hall mode that shines"3. JHS Pedals' writer went further on the hall setting:
"I love the hall setting because it's dark, it's gloomy and it sits in a mix really well"4
JHS Pedals, on the Holy Grail13
The same JHS writer reported using the pedal on boards for years, always on4. On Flerb, though, reviewers split sharply. The JHS writer called it "literally the worst reverb setting I've ever heard"4, while EHX's own description frames it as a unique ethereal sound4. In a JHS video demo, Josh recommended the hall setting for the pedal, saying "the best Reverb sound you can get for this is the haul setting"14.
The Holy Grail's circuit also turned up inside other EHX products. Vintage Guitar's review of the Epitome noted that "the Holy Grail digital reverb section provides settings for Spring (classic surf sounds), Hall (big cathedrals), Room"15, and Pedal of the Day traced a Cathedral preset back to the Holy Grail Reverb pedal16. Players curious where the family went next can look at the Oceans 11 and the wider EHX reverb line.
Videos
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Questions
Is the Electro-Harmonix Holy Grail analog or digital?
Digital. Vintage Guitar described the original as a digital reverb pedal when it reviewed it in 2002, and Electro-Harmonix lists the Nano, Neo, Plus and Max versions as digital circuits as well. The spring mode is a digital emulation rather than an actual analog spring tank, which is how the pedal stays compact.
What is the Flurb setting on the Holy Grail?
The setting is officially called Flerb, and some reviewers pronounce or spell it differently. Electro-Harmonix describes it as flanging combined with spatial reverb, producing an ethereal, modulated reverb sound. MusicRadar's reviewer called it a feature that mixes reverb with flange, while JHS Pedals' writer was far less fond of it.
What is the difference between the Holy Grail Nano and the original?
The Nano is a compact version of the original Holy Grail, available alongside the larger original enclosure. It carries the same three modes, Spring, Hall and Flerb, with a single Reverb knob and a three-way selector switch. Gearnews describes it as a compact and straightforward reverb pedal built for classic ambience without taking up much board space.
Which Holy Grail has a reverse reverb?
The Holy Grail Max. Electro-Harmonix gives it four reverb types: Spring, Hall, Plate and Reverse. The other versions stop at three or four non-reverse modes, so a player specifically after a reverse reverb sound is looking at the Max.
Has the Holy Grail Plus been discontinued?
Yes. Electro-Harmonix marks the Holy Grail Plus as discontinued in 2022 on its product page. The Plus added a Room mode to the original's Spring, Hall and Flerb reverbs, but it is no longer in production.
Sources (16)
- Electro-Harmonix Holy Grail, Vintage Guitar magazine, 2003-04-01
- Holy Grail Nano, Electro-Harmonix
- 5 great reverb pedals guitar players need to try, MusicRadar (www.musicradar.com), 2021-10-12
- MY FIVE FAVORITE REVERBS (FOR NOW), JHS Pedals
- Holy Grail Max, Electro-Harmonix
- Electro-Harmonix Expands Reverb Line with Holy Grail Neo, Guitar Interactive Magazine, 2015-03-18
- Best Spring Reverb Pedals 2025: Sunny Sounds for Surf Rock and Skate Punk, gearnews.com, 2025-07-07
- Pedalboard Feature: Mike Gavrailoff, Strymon, 2015-12-15
- Holy Grail Neo, Electro-Harmonix (ehx.com)
- Electro-Harmonix Unveils the Holy Grail Neo, Guitar.com, 2015-03-26
- Holy Grail Plus, Electro-Harmonix (ehx.com)
- Demo Video: Electro-Harmonix Introduces Holy Grail Max Reverb Pedal, Guitar World, 2014-02-25
- 3 SERIES PHERB, JHS Pedals, 2026-10
- How To Get Any Blues Tone (EHX Holy Grail, Dunlop Band of Gypsies Fuzz Face, JHS Unicorn), JHS Pedals (YouTube), 2024-09-19
- Electro-Harmonix Epitome, Tone Tattoo, Vintage Guitar magazine, 2014-12-16
- Electro-Harmonix Cathedral Stereo Reverb, Pedal of the Day, 2016-04-05
