Fuzz bass, also called "bass overdrive" or "bass distortion", is a style of playing the electric bass or modifying its signal that produces a buzzy, distorted, overdriven sound, which the name implies in an onomatopoetic fashion. Overdriving a bass signal significantly changes the timbre, adds higher overtones (harmonics), increases the sustain, and, if the gain is turned up high enough, creates a "breaking up" sound characterized by a growling, buzzy tone.
One of the earliest examples may be the 1961 Marty Robbins Country and Western song "Don't Worry." By the mid- to late-1960s, a number of bands began to list "fuzz bass" in addition to "electric bass" on their album credits. Two well-known examples are the Beatles' 1965 song "Think for Yourself" (from Rubber Soul), which marked the first instance of a bass guitar being recorded through a distortion unit, and the 1966 Rolling Stones song "Under My Thumb". Album or performance credits for fuzz bass can be found from every decade since then (see examples below).
Fuzz bass can be produced by overloading a bass amp's tube or transistor preamplifier, by using a bass fuzz or bass overdrive effect pedal, or for the most powerful effect, by combining both approaches. In the 1960s and early 1970s fuzz bass was associated with the psychedelic music (e.g., Edgar Broughton Band), progressive rock (e.g., Genesis), and psychedelic soul/funk (e.g., Sly and the Family Stone) styles, and it tended to be a "warmer", "smoother", and "softer" overdrive-type sound caused by soft, symmetrical clipping of the audio signal that "round[ed] off the signal peaks rather than razor-slicing" them and filtered out the harsher high harmonics.
In the context of electric guitars, the terms "distortion", "overdrive" and "fuzz" are often used interchangeably, but they have subtle differences in meaning. Overdrive effects are the mildest of the three, producing "warm" natural overtones at quieter volumes and harsher distortion as gain is increased. The best quality overdrive effects respond to how hard the bassist picks or plucks the bass, producing little or no distortion when the instrument is played quietly, but gradually adding overdrive as the instrument is played harder. A "distortion" effect produces approximately the same amount of distortion at any volume, and its sound alterations are much more pronounced and intense. A fuzzbox (or "fuzz box") alters an audio signal until it is nearly a square wave and adds complex overtones by way of a frequency multiplier.
Waveform plot showing the different types of clipping. Tube overdrive is a form of soft limiting, while transistor clipping or extremely overdriven tube amps resemble hard clipping.
A fuzz bass sound can be created by turning up the volume of a tube amp or transistor amp to the point that preamplifier tube (or transistor preamp) clipping" occurs. In practice, when a bass amp is "cranked" to its maximum volume, the fuzz tone will also include some power amplifier clipping. While some musicians seek out the additional "grit" provided by power amp clipping, audio engineers and bass technicians recommend avoiding power amp clipping, as it can blow speakers. In the 2010s, a number of specialized fuzz bass pedal effects are sold, ranging from mass-produced commercial models to expensive boutique pedals. Fuzz bass can also be produced by using an electric guitar fuzz, distortion or overdrive pedal. The downside of using a pedal designed for the electric guitar is that the lower-end bass tone is mostly lost when the signal is heavily clipped.
Clipping is a form of waveform distortion that occurs when an amplifier is overdriven and attempts to deliver an output voltage or current beyond its maximum capability. Driving an amplifier into clipping may cause it to output power in excess of its published ratings. Clipping is a non-linear process that produces frequencies not originally present in the audio signal.
Since the late 1980s, manufacturers have been producing bass overdrive pedals specifically designed for the electric bass, and in many cases they found a way to keep the low fundamental pitch in along with the buzzy overdrive tone. One early model was the Ibanez "Bass Stack" bass overdrive pedal, which was sold in the late 1980s.
1980s grindcore groups, such as Napalm Death in the sound clip to the right, used a very heavy, distorted bass tone that resembles the sound of a grinding buzz saw.
The simplest fuzz bass pedals have knobs for controlling the volume level, the tone, and the fuzz or overdrive effect. More complex pedals have different distortion effects (e.g., overdrive and fuzz), gates to trigger the volume at which sounds will get overdriven, mixers to mix the natural and fuzzed sound in the player's desired proportions, and multiple band equalizers (typically for low and high frequencies). Boutique fuzz bass pedals even have unusual effects such as a "starve" effect, which mimics the distortion sound a pedal gives with a dying battery, a diode selector (either silicon or germanium) for selecting the transistor overdrive tone, and an octave selector (above or below the pitch being played).
While fuzz bass pedals are most commonly used by bass players, some electric guitar players use bass overdrive units. Buzz Osborne, electric guitarist from the Melvins, uses a BOSS Bass Overdrive ODB-3 pedal.
NYC re-issue & a Russian Sovtek version of the Big Muff
Standard overdrive effects for bass include:
The AGRO bass overdrive is produced by Aguilar Amplification. The manufacturer claims that the pedal is "based on the saturation channel of Aguilar's celebrated AG 500 bass head" and that it can produce "everything from warm, tube-like overdrive to full on distortion" and all the "grind you need without sucking out your low end." It has a saturation (overdrive) knob, a contour knob, a presence knob, and an output knob.
The Bass Brassmaster was introduced by Gibson in the early 1970s. A fuzz box variant, it used "induction circuitry to produce a brassy sound for bass guitar".
The Bass BB Preamp distortion booster has bass and treble EQs. The manufacturer states that the "gain knob offers pristine clean boost to a hard overdriven distortion" and "compression for a smooth overall texture."A demonstration is provided at this YouTube link.
The Bass Drive Plus pedal is made by Ashdown, an amplifier manufacturer. The maker claims that the product "generates a wide range of bass distortion effects from a slight grunge through to no holds barred, high-gain overdrive". It has knobs for "Drive", "Tone", and "Level", and it has a VU meter.
The BASS OVERDRIVE BOD 100 is a low-priced pedal from Behringer. The maker claims that it produces "...rich, tube-like distortion, smooth sustain and super-fat tone" and that it is "designed specifically for bass, so the bottom-end won't drop out" when the distortion is turned on.
The EBS Metal Drive Universal Distortion Pedal is a bass distortion pedal. The maker claims that it provides "high-gain distortion for use in modern metal music. The manufacturer claims that it has a "fat tone that keep the bottom solid."
The El Grande Bass Fuzz is made by MXR Bass Innovations. The manufacturer claims that it is "a versatile and brutal fuzz designed just for bass" that takes a "classic 70's fuzz circuit, re-tune[s] it for more low end,...[adds] a DEEP switch. There are also "Volume, Tone, and Fuzz controls".A demonstration of the El Grande is available on YouTube.
The MXR Bass Blowtorch is a multipurpose pedal. The maker claims it can provide "anything from the traditional tube-like growl to scorching high gain distortion." The pedal "focusing the overdrive in the midrange frequencies." It has a three-band EQ and a blend knob for blending the clean signal with the overdrive signal.A demonstration of the Bass Blowtorch is available in this YouTube video.
The GNI BSH Bass Shaper Pedal has an "Overdrive / Super Overdrive" setting to adjust the distortion. There are also "Drive" and "Level" knobs, and a "Super Overdrive" button.
The Ibanez TS9B Bass Tube Screamer is a version of the classic Tube Screamer reconfigured for bass players. It has Level, Gain, Treble, Bass, and Wet/Dry Mix Controls.
The Soundblox Pro Multiwave Bass Distortion is manufactured by Source Audio. The manufacturer claims that it offers "23 modern and distinctive distortion" options. It also has a "7-band equalizer, drive control, and separate mix knobs for clean and distorted signals." 
The Soundblox Multiwave Bass Distortion is manufactured by Source Audio. It has less features than the Pro version, but it uses the same approach. It offers "21 varieties of [the company's] distortion algorithm," and the distortion can be allocated to specific frequencies.
The Tech 21 Bass Boost Fuzz produces sounds ranging "from the fat, gritty sounds of the '60s fuzz bass, to the subterranean growl of industrial metal." As well, like the MXR Bass Fuzz and the BOSS Bass Overdrive, it enables the user to set how much "clean" bass tone is present along with the overdrive tone.
Boutique pedals are designed by smaller, independent companies and are typically produced in limited quantities. Some may even be hand-made, with hand-soldered connections. They are often more expensive than mass-produced pedals and offer non-standard features such as true-bypass switching, higher-quality components, innovative designs, and hand-painted artwork.
The BASS BLOOM by FuzzHugger, is purported to provide "low-end and smooth clean blending", with gain, bloom (fuzz), starve (mimics a dying battery), clean volume and fuzz volume controls. The Premier Guitar review from October 2012 states that it "...offered endless textures of fuzz, while effectively preserving the low end". As well, it "...allows you to create a spectrum of different fuzz tones that work well with both active and passive basses. Bassists from rock to funk camps can find a number of useful sounds within its responsive controls, all at a price point that is competitive with its peers."
The Bass TightDrive overdrive pedal is designed to "provide tighter low end." The pedal has a "Tight" knob, which allows the attack to vary from "smooth and singing to [a] chunky and aggressive attack." There are also Gain, Tone, and Volume controls, which enable the player to produce a variety of overdrive tones.
The Battering Ram Overdrive and Fuzz, from Wounded Paw Effects, is designed for both electric guitar and electric bass. It has an overdrive switch, low and high frequency knobs, and a "fuzz" switch. There is also an "octave up" switch.
The Black Cat Pedals Bass Octave Fuzz Pedal is inspired by the 1970s Bass Brassmaster pedal. The manufacturer claims that it adds a "unique fuzz tone that harkens back to that famous bass grind of the '70s."
The Brown Dog fuzz pedal "produce[s] rampaging waves of meat [i.e., fuzz] with your bass guitar while still keeping your basslines tight and letting the character of your instrument's tone shine through." It has controls for "dirty", "clean", a gate control that determines at which point the fuzz will be created, and a "drive" control that ranges from "hard mode with maximum drive, ...[giving]...synth-like square wave tones" to soft mode, which "produces a classic warm bass fuzz."
The Devi Ever FX Bass Fuzz is "bass heavy fuzz with [an] expansive filter tone control", which enables the player to "emphasize the highs, or lows" and an "intensity flip switch" that "increases fuzz intensity."
The Depth Charge pedal by Prescription Electronics is "60s fuzz"-style effect. A Harmony Central review states that it add "a ton of fat tone, attack and (just the right amount) of fuzz."
The Frantone Bassweet V1 is a "germanium transistorized bass" fuzz pedal. The manufacturer, Frantone Electronics claims that it can produce "an impenetrable wall of low end" with a range of "sustain, compression, and tone" options.
The FUZZPOTION pedal from Audio Monk is designed to provide fuzz for both electric guitar and electric bass. The manufacturer claims it provides "Fuzz/distortion so destructive you'll rule the world!"
The FZ002 bass fuzz is produced by Chunk Systems. The manufacturer claims that it has a "gating system to keep your basslines punchy and well defined whether you've got it set to make your sound a little crusty round the edges or transform it into rampaging waves of meat." It is handmade in Australia to order.
The Hematoma, from HomeBrew Electronics is a "two channel bass guitar pedal consisting of a Pre-Amp and an Overdrive" that "can be used independently or combined. The manufacturer claims that there is "[n]o loss of low end." 
The "Iron Ether Oxide" pedal is "a morphing gated fuzz, allowing the user to seamlessly morph between a raucous, industrial octave fuzz inspired by the Maestro Bass Brassmaster, to a modern synthy fuzz with a pinched, gated sound. It includes a clean blend to allow extreme amounts of fuzz without losing low end.". Each Iron Oxide pedal is hand-etched and painted.
Laser Cannon HD from Daring Electronics is a bass distortion pedal. The manufacturer claims that it "[s]trikes the perfect balance of clean bass mixed with heavy distortion" and produces a range of sounds "from moderate to crunchy distortion or even thick fuzz", making it suitable for "rock, metal, industrial and hardcore" bands. It has a signal blend knob, an EQ knob, a range knob, a wave knob, a diode selector (either silicon or germanium), and octave selector (for adding an octave above or below), and a volume knob. An update version features selectable FET, Silicon and Germanium diodes, as well as a low, band or high EQ selection switch in place of the octave switch.
The LODESTONE Bass Fuzz is made by Monolith Loudspeakers. The manufacturer claims that it is a "high gain transistor fuzz that will unleash the beast in your bass tone!"
The Mad Professor Blueberry Bass Overdrive has a drive control and circuitry that "compresses and adds more signal distortion for a smooth, long sustaining tone." The Nature control "controls filtering but also determines what register distorts." 
The MessDrive Bass Fuzz Pedal is made by ElectroniX. The manufacturer claims that it "make[s] the bass sound like how it should: A bass fuzz pedal that doesn't kill the low end, in fact adds fat bottoms."
The Microtubes B3K is made by Darkglass Electronics. The manufacturer claims that it offers a range of sounds, ranging from "warm, clear, and punchy tube-like Overdrives, to devastating Raging Bass Distortions, all without losing a gram of low end or definition." Justin Meldal-Johnsen (Nine Inch Nails) praises its "big overdrive sound" and states that it is "highly recommended." A demonstration of the product on YouTube shows its wide range of sounds.
The Photon Fuzz from FEA Labs uses "infrared light to control the fuzz distortion element."  Designed for "both bass and guitar players[,] [t]here are three controls for the fuzz and its level, with a 3-band EQ to shape the fuzz tone." As well, there is a "dry blend level control... for bass players and...an octave distortion level control."
The Pickle Pie B Bass Distortion Pedal is made by Wren And Cuff. It has a "FET buffered active clean boost so you won't get any "drop-out" when you kick on the fuzz when playing live." As well, there is a "mid-scoop to help retain presence in a live playing situation".
The Screamer Bass Fuzz pedal by Cusack Effects enables the player to "mix either the overdrive or the fuzz to your liking...from subtle grit to buzz saw." A reviewer noted the "build quality", with "mini chickenhead knobs [made] in house". The reviewer noted that it has a "Clip Selector: This allows you to select either the Standard, Crushed, or Asymmetrical LED clipping." The reviewer noted how "noise-free the circuit is."
The Supa Tone by Skreddy Pedals is a fuzz that can be used by bassists or guitar players. The manufacturer claim that when used for bass, it produces a "grindy, tubey distortion that stays in the pocket" and the player can add "as much low end as you like." As with many boutique pedals, there is a waiting list to obtain this product.
The Super Bass Bit Fuzz by FX Doctor provides "thick, fuzzy low end...[and] a wall of compressed tone" and it can provide either harsh or mellow fuzz tone.
The Woolly Mammoth fuzz bass from Z.Vex Effects is a hand-painted pedal with settings for output, equalization, "pinch", and "wool."
Overdrive built into amplifiers
Over the years, various Peavey bass amplifiers have had built-in distortion effects.
Some bass amplifiers have an "overdrive" or distortion effect built into the unit. The Peavey Century 200 has an onboard "distortion" effect on the second channel. The Peavey VB-2 also has built-in overdrive. Aguilar Amplification's AG 500 bass head is a two-channel amplifier, one of which offers a "saturation" control for overdrive. A variety of BOSS combo amplifiers have a built-in "drive" effect. Gallien-Krueger's bass amp heads have a "boost" control that provides a simulated tube overdrive effect. The Behringer Ultrabass BVT5500H Bass Amplifier Head has a built-in limiter and overdrive. The LowDown LD 150 bass amp has a range of overdrive sounds, from a slight hint to heavy distortion. The CUBE-20XL BASS amp includes built-in overdrive.
The 75W Fender Rumble 75 Bass Combo Amp can produce an overdrive effect by using the gain and blend controls, giving overdrive sounds ranging from "mellow warmth [to] heavy distorted tones". The Fender SuperBassman is a 300-watt tube head that has a built-in overdrive channel. The Fender Bronco 40 includes a range of effects including modern bass overdrive, vintage overdrive and fuzz.
Lemmy Kilmister, the bassist for Motorhead, obtained a natural fuzz bass tone by overdriving his twin 100 watt Marshall Bass stacks.
The MESA Bigblock 750 has a built-in overdrive channel. The Mesa M2000 has a high gain switch that can be engaged with a footswitch. The Marshall MB450 head and combo bass amplifiers have a tube pre-amp on the "Classic" channel that can be overdriven. The Ashdown ABM 500 EVO III 575W Bass amp head has a built-in overdrive effect. Overdrive is also available on many Crate bass amplifiers. The Yamaha BBT500H has three types of built-in drive effects: overdrive, distortion and fuzz. The Ampeg B5R Bass Amplifier has two channels: clean and overdrive, with the ability to combine the two.
The Orange has introduced a new line of bass amplifiers(OB 1 series) with a built in fuzz.
Verellen, a boutique amp company, produces a bass amplifier with a built in overdrive channel.
The following section gives examples of songs that feature fuzz bass.
Napalm Death, a grindcore band shown here at a 2007 show, typically uses a heavy, grinding bass distortion tone.
Motörhead bassist Lemmy's bass sound has been called "fuzz-tone bass" by music critics.In the 1980 song "Ace of Spades", his fuzz bass tone can be clearly heard. "Lemmy uses no effects pedals: the distortion is produced naturally by the valve [tube] amplifiers, [and] the high volume, [which] gives a classic valve, 2nd harmonic distortion."
On Metallica's debut album "Kill 'Em All", the song "(Anesthesia) - Pulling Teeth" is an instrumental bass solo by Cliff Burton featuring the use of fuzz-wah; Metallica's 1984 album Ride the Lightning features a short bass intro at the start of the song For Whom The Bell Tolls, which features fuzz-wah, as well as in the instrumental "The Call of Ktulu", which also features Burton's signature lead bass style; on the album Master of Puppets, Burton used slightly driven bass in the intro of "Damage, Inc." as well as great instrumental "Orion" which features few fuzz-wah bass solos, also fuzz bass can be heard in the song "The Thing That Should Not Be".
Grindcore band Extreme Noise Terror's song "Deceived" uses a grinding, distorted bass tone that can clearly be heard in the short bass intro at the start of the song.
Frank Zappa's Apostrophe (') (1974) features "an amazing jam played by Jack Bruce with his fuzz bass, dirty and brutal as when he was in Cream."
The 1971 progressive rockers Emerson Lake & Palmer featured buzzy fuzz bass on some songs on the Tarkus LP.
In 1970, the Australian psychedelic and progressive rock band Tamam Shud released a song entitled "Goolutionites and the Real People", which credits Peter Baron on bass and fuzz bass. Two years later, Baron was also credited for fuzz bass for the song "Got A Feeling", which was penned for the surf film "Morning Of The Earth".
The bass guitarist of the American heavy psychedelic group The Damnation of Adam Blessing Ray Benich used a unique, raw and violent kind of fuzzy bass sound in their 1970 second album "The Second Damnation" in most of the songs.
The American heavy psych/hard rock power trio Truth and Janey also used a distorted bass sound in their early years.
"Inside Looking Out" (1969) by Grand Funk Railroad features fuzz bass for several bass breaks midway through the song.
Cream, Goodbye (1969): "Jack Bruce [during] his Cream period always used fuzz on his bass."
Edgar Broughton Band's Wasa Wasa (1969); called the "best UK heavy psychedelic album ever, this ha[s] a lot fuzz on the bass."
The Litter's Emerge (1969) is "magnific heavy garage/psych/proto-punk with the typical 60's flavor but more heavier, with some pre-sabbathian atmosphere and a constant use of fuzz in the bass guitar" 
The 1969 song "Some Velvet Morning" by Vanilla Fudge has a growly fuzz bass tone.
The United States of America (1968) has "spacey and experimental psychedelia with electronic, avant-garde, noise and proto-punk elements, with maybe, the best fuzz bass ever recorded."
The 1967 song "Sodding About" by The Who used fuzz bass.
The 1967 song "Zig-Zag Wanderer" from the album Safe As Milk by Captain Beefheart & His Magic Band starts out with regular bass, but then 2/3 into the song, the bass turns into fuzz.
The 1967 Jefferson Airplane song "She Has Funny Cars" features Jack Casady on fuzz bass. Casady has an extensive fuzz bass solo, self-accompanied with chords, on a live version of "Ballad of You and Me and Pooneil".