The MXR M103 Blue Box is an MXR fuzz pedal. Close alternatives include the Catalinbread Perseus and the Electronic Audio Experiments Eldritch Blast V3. It pairs well with the Marshall Plexi 1959SLP and the Fender Bassman Combo Amp.
MXR M103 Blue Box
MXR · pedal
The MXR M103 Blue Box is an octave fuzz that duplicates the guitar signal two full octaves down for a huge, subterranean, synth-bass tone layered with fuzz. The Blend knob controls the balance between the fuzz and the sub-octave signal: turned fully one way it is a nasty, straightforward fuzz, turned fully the other way it becomes a fat, fuzzy synth-bass tone, and pushed toward its extreme it starts spitting, glitching, and tracking unpredictably for a raw, 8-bit-like chaos. It became a gear icon after Jimmy Page used it for the solo on Fool in the Rain, and has since been used by Jack White, Lee Ranaldo, and Thurston Moore. It suits players wanting an uncontrollable, glitchy, monstrous octave-down fuzz for experimental, psychedelic, and heavy styles rather than a clean, predictable octave effect.
What stands out
“The MXR M103 Blue Box is an octave fuzz that duplicates the guitar signal two full octaves down for a huge, subterranean, synth-bass tone layered with fuzz”
— from the listing
“[Pros] ✓ Unique fuzz/octave effects create distinctive sounds ✓ Durable, "built like a brick" construction ✓ Inspires creativity with glitchy, bitcrusher sounds for unique lead lines ✓ Versatile for various genres including rock, metal, and…”
— from the reviews
“The Blend knob controls the balance between the fuzz and the sub-octave signal: turned fully one way it is a nasty, straightforward fuzz, turned fully the other way it becomes a fat, fuzzy synth-bass tone, and pushed toward its extreme it s…”
— from the listing
“It suits players wanting an uncontrollable, glitchy, monstrous octave-down fuzz for experimental, psychedelic, and heavy styles , predictable octave effect”
— from the listing
- octave fuzz
- octave
- experimental
- sub
- glitchy
- distortion
- thick
- distinctive sounds
Good for
- Busking
Genres the MXR M103 Blue Box is commonly used in
Amps that pair well with the MXR M103 Blue Box
Marshall Plexi 1959SLP
amplifier
20% matchUsed together by 1 artist
Documented together in one player's rig - the Blue Box's octave fuzz turns thick and wild through the 1959SLP's aggressive plexi saturation.
Comes later in the signal chain
Fender Bassman Combo Amp
amplifier
19% matchWhat Fender Bassman Combo Amp brings here leans toward crunchy — that's worth building a pairing around
Comes later in the signal chain
Pedals that stack with the MXR M103 Blue Box
Fulltone OF-2 Octafuzz
Fulltone
26% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
MXR M103 Blue Box stacks octave on top of the fuzzy already here
Electro-Harmonix Satisfaction Plus Fuzz
Electro-Harmonix
26% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
MXR M103 Blue Box stacks octave on top of the fuzzy already here
Fairfield Circuitry 900 Fuzz
Fairfield Circuitry
26% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
MXR M103 Blue Box layers octave onto an already fuzzy signal
Dunlop Fuzz Face Mini Germanium
Dunlop
23% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
MXR M103 Blue Box layers octave onto an already fuzzy signal
Zvex Limited Edition 20th Anniversary Fuzz Factory
Zvex
22% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
MXR M103 Blue Box layers octave onto an already fuzzy signal
Wren and Cuff Tall Font Russian
Wren And Cuff
20% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
Run fuzzy into MXR M103 Blue Box for more octave on top
Comes earlier in the signal chain
Mooer MFZ1 Blue Faze
Mooer
20% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
Run fuzzy into MXR M103 Blue Box for more octave on top
Pigtronix Gas Giant
Pigtronix
19% matchsits in the right chain slotPlaced for where it does its job cleanly in the chain, not for a tonal interaction with the anchor. (fuzzy → octave)
MXR M103 Blue Box stacks octave on top of the fuzzy already here
Comes earlier in the signal chain
Alternativessee all similar tone character →
Catalinbread Perseus
Catalinbread
64% similarityShared character: each note, mono synth, tight tracking
Electronic Audio Experiments Eldritch Blast V3
Electronic Audio Experiments
60% similarityShared character: mono synth, one octave
EarthQuaker Devices Data Corrupter
EarthQuaker Devices
60% similarityShared character: each note, mono synth, tight tracking
Fender Kevin Shields Blender
Fender
57% similarityShared character: one octave, simple, full
JHS Pedals JHS Coyote
JHS Pedals
55% similarityShared character: two octave down effect, tonal possibilities, one octave
Fairfield Circuitry The Unpleasant Surprise
Fairfield Circuitry
55% similarityShared character: mono synth, fat, one octave
Boss FZ-5 Fuzz
Boss
54% similarityShared character: fat, one octave
Pigtronix OCT2
Pigtronix
53% similarityShared character: tight tracking, one octave
JAM Pedals Octaurus
Jam Pedals
53% similarityShared character: two octave down effect, mono synth, one octave
Dunlop MXR SUB Machine
Dunlop
52% similarityShared character: mono synth, tight tracking, one octave
Fender Blender
Fender
52% similarityShared character: raw, tight tracking, one octave
Dunlop JHMS2 Hendrix Shrine Series Octavio Fuzz
MXR
52% similarityShared character: each note, one octave, lead
See all alternatives to the MXR M103 Blue Box (cheaper + boutique) →
Questions people ask
What are good alternatives to the MXR M103 Blue Box?+
The closest matches in character are the Catalinbread Perseus, the Electronic Audio Experiments Eldritch Blast V3, the EarthQuaker Devices Data Corrupter.
What pairs well with the MXR M103 Blue Box?+
Strong matches from rig and tone-complementarity evidence: Marshall Plexi 1959SLP, Fender Bassman Combo Amp, Fulltone OF-2 Octafuzz — Documented together in one player's rig - the Blue Box's octave fuzz turns thick and wild through the 1959SLP's aggressive plexi saturation..