The JAM Pedals Harmonious Monk is a tremolo pedal that puts two tremolo voices in one box: a Harmonic mode and an Amplitude mode. It was designed jointly by JAM Pedals and Dan and Mick of That Pedal Show, and it is built by hand in Greece12. The circuit is all analog, and the pedal runs from subtle, flowing modulation to hard staccato chop34.
Harmonic mode is the voice the pedal is known for. JAM Pedals describes it as creating "rich, phase-like movement," while Amplitude mode "provides traditional volume modulation"4. In other words, Harmonic mode is the vintage style where the high and low parts of the signal swell against each other, so the effect sits somewhere between a tremolo and a phaser, and Amplitude mode is the straight volume swell most players picture when they hear the word tremolo. On That Pedal Show's demo of the pedal, Dan and Mick described the harmonic character as "a little bit phase-y and a little bit pulsing"2.
The two tremolo voices
A lower toggle switch chooses between the Amplitude Tremolo and the Harmonic Tremolo voicing6. The two modes are the core of the pedal's appeal, and reviewers consistently single out the Harmonic voicing. Guitar Pedal X's Stefan Karlsson, comparing it against another multi-mode optical tremolo in 2026, wrote:
"I still really rate the Harmonious Monk which still has my favourite Harmonic voicing"7
He also noted the Monk's Harmonic voicing "goes a little more intense" than the competing pedal's harmonic mode7. Gearnews' 2025 tremolo buying guide describes the circuit as fully analog with three LFO shapes and a switchable harmonic/amplitude mode, "voiced for players who care about nuance and touch"5.
The controls, switches and internal trimmers
The mk.2 carries four knobs on top: Depth sets intensity, Speed sets rate, Level controls output, and Mix blends the dry and wet signals3. A waveform selector offers square, sine or reverse-sawtooth modulation4. The original mk.1 used an Intensity switch and a mode switch instead1.
Inside, there is more shaping available:
- Treble, Midrange and Bass trimmers shape the effected (wet) signal3
- A fourth trimmer adjusts the wet-path input gain, which Delicious Audio notes makes the pedal compatible with any instrument, including bass2
The input and output are in phase, so the pedal does not flip the polarity of your signal3.
| Control | What it does |
|---|---|
| Depth | Sets intensity; fully clockwise in Amplitude mode with square wave gives kill-dry CHOP3 |
| Speed | Sets rate3 |
| Level | Controls output3 |
| Mix | Blends dry and wet signals3 |
| Waveform switch | Square, sine or reverse-sawtooth modulation4 |
| Mode toggle | Harmonic or Amplitude tremolo485 |
Tap tempo, ramp and Legacy mode on the mk.2
Tap & Ramp mode is the default. Tap the right footswitch to set tempo. Hold it to ramp from the current rate to a second speed: while holding TAP, Speed defines the destination rate and Depth defines the travel time3. That ramp is the feature that lets you sweep from a slow swirl to a fast chop under your foot mid-song.
Legacy mode preserves the original pedal's speed-multiplication workflow for players who came up on the mk.1. In Legacy mode the right footswitch toggles speed multiplication, and you choose x2 or x1.5 by holding TAP until you see two or three confirmation blinks3.
The mk.2 also adds a kill-dry CHOP function: in Amplitude mode with the square wave selected, turn Depth fully clockwise and the pedal alternates between sound and silence3. Guitar Pedal X's round-up of 2023's modulation and utility pedals lists the mk.2's modes as Up Harmonic / Down Amplitude, its waveforms as Square / Sinewave / Reverse Sawtooth, and its tempo features as Tap Tempo / Speed Ramp / x2 Speed9.
Power
The pedal runs on 9V DC, center negative, and JAM Pedals recommends an isolated supply. Maximum current draw is 145 mA3.
At 145 mA the Harmonious Monk draws more current than many analog pedals, and the maker recommends an isolated supply rather than a daisy chain.
History: That Pedal Show, the first batches and the mk.2
The mk.2 arrived in April 2023, described by That Pedal Show as building on "JAM Pedals' award-winning collaboration with That Pedal Show"10. Premier Guitar's 2024 review calls it "the second iteration of JAM's Harmonious Monk," a tremolo pedal "designed with Dan and Mick from That Pedal Show," with amplitude- and harmonic-style tremolo plus a tap tempo switch8. The mk.2 has since appeared in That Pedal Show's video database, including a Five Fantastic Phasers episode that lists it among the pedals and stuff section, with harmonic trem sounds demonstrated at 51:5011.
Limited artwork editions
JAM Pedals sells the Monk in one-of-a-kind hand-painted limited artwork versions, the house style the builder is known for. Each is the same circuit with different artwork, and the pedal you receive will differ in detail from the photos shown1213141516. The versions include:
- "Beast" and "Cactus Totem" (mk.1 circuit, one-of-a-kind hand-painted custom artwork)1214
- "Arachnid" (mk.1 circuit, one-of-a-kind hand-painted custom artwork)14
- "Achenbach" and "Relic" (mk.2 circuit, one-of-a-kind hand-painted custom artwork)14
JAM Pedals also sells B-stock mk.2 units: pedals that did not pass the cosmetic quality check but are otherwise brand new, fully working, and covered by the life-time warranty3.
What reviewers said
Published reviews of the Monk have been consistently positive:
Who uses it
JAM Pedals lists guitar players who use the pedal, including Jim Campilongo on the mk.23. Two artists give the pedal their own words on JAM Pedals' artist pages:
"The Harmonious Monk ended my search for the perfect all around tremolo pedal."
Simon McBride, quoted on the "Beast" edition's page, wrote: "Got the pedals today, i have to say these things are F*****g awesome, excuse my language, they are really musical and i can use them on anything…"12
Videos
That Pedal Show
That Pedal Show
Pete Thorn
News
Questions
Is the Harmonious Monk true bypass?
Yes. JAM Pedals lists true bypass for the Harmonious Monk and every version of the mk.2, including the limited artwork editions. Guitar.com's review of the original also notes true-bypass switching.
What is the difference between the Harmonious Monk mk.1 and mk.2?
The mk.2 keeps the original's all-analog circuitry and tone but adds Tap & Ramp mode, three selectable LFO waveforms (square, sine, reverse sawtooth), Legacy mode, a kill-dry CHOP function, an input gain trimmer and internal EQ trimmers. The mk.1 has a mode switch and internal treble, middle and bass trims but no tap tempo.
Does the Harmonious Monk have tap tempo?
The mk.2 does. In Tap & Ramp mode, tapping the right footswitch sets the tempo, and holding it ramps from the current rate to a second speed, with Speed setting the destination and Depth setting the travel time. The original mk.1 does not have tap tempo.
Is the Harmonious Monk analog or digital?
It is all analog. JAM Pedals lists the circuit as all analog for the original and for every version of the mk.2, and press reviews describe it as a fully analog harmonic tremolo circuit.
What does harmonic tremolo sound like compared to regular tremolo?
Harmonic tremolo splits the signal and modulates the high and low bands against each other, so it moves like a phaser as much as a volume swell. JAM Pedals describes Harmonic mode as rich, phase-like movement, while Amplitude mode is the traditional volume modulation most players think of as tremolo.
Can the Harmonious Monk do a hard chop or stutter tremolo?
Yes, on the mk.2. Select Amplitude mode with the square wave and turn Depth fully clockwise to activate kill-dry CHOP, which alternates between sound and silence. JAM Pedals also describes the pedal's range as running from subtle, flowing modulation to hard staccato chop.
Sources (17)
- Review: JAM Pedals Harmonious Monk, Guitar.com, 2021-03-11
- Jam Pedals Harmonious Monk Mk2 Tremolo, Delicious Audio, 2024-08-05
- Harmonious Monk mk.2 B-stock, JAM Pedals (jampedals.com)
- Harmonious Monk, JAM Pedals (jampedals.com)
- The 9 Best Tremolo Pedals for Any Budget: Vintage Pulses and Modern Vibes, gearnews.com, 2025-12-22
- Jam Pedals and That Pedal Show release the Harmonious Monk, gearnews.com, 2020-12-13
- Guitar Pedal X, Guitar Pedal X, 2026-04-16
- JAM Pedals Harmonious Monk mk.2 Review, Premier Guitar, 2024-01-21
- Guitar Pedal X, Guitar Pedal X, 2023-12-19
- Harmonious Monk Mk.2, That Pedal Show, 2023-04
- Five Fantastic Phasers Plus Phaser Tips & Tricks, That Pedal Show, 2026-05-15
- "Beast" Harmonious Monk, JAM Pedals (www.jampedals.com)
- "Arachnid" Harmonious Monk, JAM Pedals (jampedals.com)
- "Cactus Totem" Harmonious Monk, JAM Pedals (jampedals.com)
- “Achenbach” Harmonious Monk mk.2, JAM Pedals (www.jampedals.com)
- “Relic” Harmonious Monk mk.2, JAM Pedals (jampedals.com)
- Matt Schofield, JAM Pedals
Joey Landreth
Matt Schofield
