The Electro-Harmonix Double Muff is a compact analog fuzz and overdrive pedal that puts two Muff Fuzz circuits in a single box. A switch selects between one Muff on its own or the two cascaded in series, which is what gives the pedal its name and its range: Electro-Harmonix describes using just one Muff for "a hint of milky distortion, or cascade the second Muff for over-the-top overdrive that turns the milk into cream"1. The pedal was discontinued in 20201.
The circuit traces back further than the pedal itself. Electro-Harmonix says the Double Muff is based on the original 1969 plug-in Muff Fuzz, which "had just a touch of overdrive and sounded like a vintage amp with a slightly torn speaker"1. The company paired two of those circuits together to create the Double Muff1.
Two Muff Fuzz circuits in one box
The Double Muff is not a Big Muff Pi. Unlike the four-transistor Big Muff Pi, the Double Muff is built on the simpler two-transistor Muff Fuzz architecture2. That makes it a smaller, more overdrive-flavored member of the Muff family rather than a full sustain fuzz, and it is one of the reasons the pedal sits somewhere between fuzz and overdrive territory.
A SINGLE/DOUBLE switch selects between one Muff in SINGLE mode or two Muffs in series in DOUBLE mode1. In Double mode the two knobs become interactive, with one adjusting the gain of the first circuit and the other controlling the overall output level2.
The pedal's production history has more than one phase. Kit Rae's Big Muff timeline records the Double Muff as discontinued in 2008, with the Nano Double Muff appearing from Electro-Harmonix in 20103. Electro-Harmonix's own product page dates the pedal to 2010 and marks it discontinued in 20201. The two sources disagree on the earlier date, so treat 2008 as applying to a previous run and 2010 to the version Electro-Harmonix documents.
The controls
The control set is minimal: two knobs, a mode switch, and a footswitch1.
| Control | What it does |
|---|---|
| MUFF 1 | Sets the overall output level in either mode1 |
| MUFF 2 | Sets the output level for the first Muff in Double mode; inactive in Single mode1 |
| SINGLE/DOUBLE switch | Selects one Muff in SINGLE mode or two Muffs in series in DOUBLE mode1 |
| Footswitch | Engages the effect or bypasses it; LED lights when engaged1 |
In practice, Single mode gives the lighter overdrive side of the pedal, and Double mode stacks the second circuit for the heavier, saturated sound. Because MUFF 2 only acts in Double mode, switching to Single mode leaves one knob doing nothing, which is worth knowing before you dial in sounds1.
Power: 9V, 3mA
The Double Muff runs on a 9V battery, which is included, or on an optional 9.6VDC-200mA power adapter, which is not1. RockBoard's PedalPedia lists the power requirement as 9V DC, center negative2, the standard arrangement for most modern pedal power supplies. Current draw is just 3mA1, low enough that a battery is a realistic long-term option and the pedal places almost no demand on a pedalboard power supply.
The Double Muff was discontinued in 20201, so it is available only on the used market. JHS Pedals notes that a modified version circulates secondhand, distinct from the original '90s big box version with a picture in the corner4.
The JHS Double Muff mod
JHS Pedals offers a modification service for the Double Muff. The mod adds a three-way clipping/gain switch to the pedal, giving three clipping and gain options where the stock pedal has none5. JHS says the mod works on both the old and new versions of the Double Muff and that the two versions sound identical after the mod5.
For a player hunting a used Double Muff, that last point matters: the version differences that exist on the secondhand market effectively disappear once the pedal has been through JHS, so condition and price matter more than which revision is on the shelf54.
Videos
ProGuitarShopDemos
EHX
Fuzzville
Questions
Is the Double Muff true bypass?
Yes. Electro-Harmonix lists true bypass for the Double Muff, so with the effect off the signal passes through without buffering. A single footswitch selects whether the pedal is engaged or in bypass mode, and an LED lights when the effect is on.
Does the Double Muff take a battery?
Yes. The pedal ships with a 9V battery included, and it can also run on an optional 9.6VDC-200mA power adapter, which is not included. Current draw is very low at 3mA, so a battery lasts a long time at typical use.
Is the Double Muff a Big Muff?
No. It is based on the simpler two-transistor Muff Fuzz architecture, not the four-transistor Big Muff Pi circuit. Electro-Harmonix says it pairs two of these Muff Fuzz circuits in one box, which is where the Double Muff name comes from.
Is the Electro-Harmonix Double Muff discontinued?
Yes. Electro-Harmonix marks the Double Muff as discontinued in 2020. Kit Rae's Big Muff history records an earlier discontinuation in 2008 for a previous run, with the Nano Double Muff appearing in 2010, so the pedal's production history has more than one phase.
What is the JHS Double Muff mod?
JHS Pedals offers a modification service for the Double Muff that adds a three-way clipping/gain switch. JHS says the mod works on both the old and new versions of the pedal and that the two versions sound identical after the mod.
Sources (5)
- Double Muff, Electro-Harmonix, 2020
- Double Muff by Electro-Harmonix, RockBoard PedalPedia, 2026
- A Fuzz and Muff pedal Timeline, Kit Rae (kitrae.net), 2014-07
- UNDERRATED ELECTRO-HARMONIX PEDALS, JHS Pedals
- EHX DOUBLE MUFF MOD, JHS Pedals
