50. IBANEZ FLYING PAN
The Flying Pan is another stomp box that combined several effects in one — in this instance phase shifting, tremolo and panning. In a stereo setup, it generates a heady, psychoacoustic effect where sound seems to circle the room. HEAR IT: Moog Cookbook, “Rockin’ in the Free World”

49. FOXX TONE MACHINE
Combining fuzz and octave-up effects, the Foxx Tone Machine was originally conceived as a Hendrix-in-a-box gizmo, but it traveled well beyond Electric Ladyland with its earthshaking, beefy distortion and squealing outer-space octave fuzz. HEAR IT: Adrian Belew, “Big Electric Cat”

48. LOVETONE MEATBALL
What the Bi-Phase is to phase shifters, the Meatball is to envelope followers. Featuring 10 control knobs for tweaking a guitar’s sound beyond recognition, the Meatball produces everything from vintage filter funk to synth-like spaced-out sounds. HEAR IT: Muse, “Sober”

47. ELECTRO-HARMONIX MICRO SYNTHESIZER
Featuring a combination of octave, square wave, attack and filter sweep controls, the Micro Synthesizer generates a variety of crude synth-like sounds that may not make you sound like Jan Hammer but are certainly useful for special effects and bizarro solos. HEAR IT: Bad Company, “Rock ’n’ Roll Fantasy”

46. HEIL TALK BOX
By sending the output signal from an amp to a tiny driver in a sealed enclosure attached to a plastic tube, the Heil Talk Box allowed guitarists to use their vocal cavity to shape sounds and make their guitar “talk.” HEAR IT: Tool, “Jambi”

45. MORLEY BAD HORSIE WAH
In addition to its wider frequency sweep range, the Bad Horsie offers the advantage of a switchless, spring-loaded electro-optical design that activates the wah effect as soon as you step on it. HEAR IT: Steve Vai, “Bad Horsie”

44. FULLTONE SUPA-TREM
Using a photocell circuit like those found in many vintage tube amps with tremolo, the Supa-Trem produces classic tremolo effects. Its Hard/Soft and Full/Half speed functions provide enhanced versatility. HEAR IT: John Fogerty, “A Hundred and Ten in the Shade”

43. LINE 6 DL4 DELAY
The DL4 features incredibly accurate models of 16 legendary delay effects, including a tube Echoplex, Roland Space Echo tape delay, Deluxe Memory Man and more. HEAR IT: Metallica, “Shoot Me Again”

42. T.C. ELECTRONIC STEREO CHORUS +
This pro-quality stomp box also provides pitch modulation and flanging, but most players use it for its pristine, shimmering, glassy chorus effects, which are in a class unto themselves. HEAR IT: Eric Johnson, “Trademark”

41. DIGITECH JAMMAN
This digital-delay looping effect started life as a rackmount Lexicon processor in 1994, but in 2005 DigiTech (which, like Lexicon, is owned by Harman) transformed the effect into a line of user-friendly stomp-box devices, including the tiny JamMan Solo, which stores 35 minutes of loops in 99 memory locations. HEAR IT: Chet Atkins, “Jam Man”

40. TECH 21 SANSAMP CLASSIC
The SanAmp’s uncanny capability to duplicate the sounds of a variety of classic tube amps made it a sensation in the late Eighties and early Nineties long before anyone heard of digital modeling. HEAR IT: Nirvana, “Scentless Apprentice”

39. DeARMOND MODEL 601 TREMOLO CONTROL
Introduced way back in the late Forties, the DeArmond Tremolo Control was the first independent effect unit ever produced for amplified instruments. This primitive device uses an electric motor to rotate a canister filled with electrolytic liquid, creating a truly organic-sounding tremolo effect as heard on early Bo Diddley, Duane Eddy and Muddy Waters singles. HEAR IT: ZZ Top, “Zipper Job”

38. ELECTRO-HARMONIX FREQUENCY ANALYZER
This ring modulator pedal can create some of the most atonal noise known to mankind, including effects that sound like the Blue Man Group whacking each other with aluminum baseball bats and steel tubes. It’s the perfect thing for your next jazz gig or stint with a Berlin group of industrial nihilists. HEAR IT: Mahavishnu Orchestra, “Cosmic Strut”

37. B.K. BUTLER TUBE DRIVER
During the Eighties, dozens of companies produced solidstate distortion and overdrive boxes that produced “tubelike” tone. B.K. Butler outdid them by making an overdrive/distortion unit actually powered by a 12AX7 tube to produce creamy distortion with violin-like sustain and sweet harmonic overtones. HEAR IT: Eric Johnson, “Cliffs of Dover”

36. ROGER LINN ADRENALINN III
The AdrenaLinn III fits the power of a digital rackmount processor into a compact stomp-box format, providing a wide variety of sophisticated effects, like beat-synched filter modulation, note-triggered filter effects and distinctive filter, tremolo and arpeggio sequences. It also includes amp models, delay loops, a drum machine and much, much more. HEAR IT: John Mayer, “Bigger Than My Body”

35. EBOW
Heard on hundreds of recordings, this simple, ingenious device generates electromagnetic waves that vibrate a guitar string and create controllable feedback-like sounds. Placed at different harmonic nodes on a string, an EBow can mimic the sounds of a cello, violin, flute or clarinet, and much more. HEAR IT: Radiohead, “My Iron Lung”

34. PRO CO RAT
Introduced during the late Seventies, the Rat distortion pedal later became associated with the sound of Eighties hair metal thanks to its use by players like Nuno Bettencourt and Steve Stevens. The Rat pedal also remained a crucial element of Jeff Beck’s signature tone from the Guitar Shop album through the Nineties. HEAR IT: Jeff Beck, “Stand On It”

33. BOSS DM-2 ANALOG DELAY
Although the DM-2’s limited delay range of 30 to 330 milliseconds didn’t set any records, its thick, warm analog echo effects have made the pedal a favorite with players who want slapback or short delay effects that don’t get lost in the mix. HEAR IT: Foo Fighters, “Rope”

32. KLON CENTAUR
Many guitarists consider the Klon Centaur the ultimate overdrive pedal. Instead of imposing its own tonal character, the Centaur’s sound is almost transparent, producing a clean boost that makes a tube amp sing like Christina Aguilera begging for another silicone injection. HEAR IT: Gov’t Mule, “New World Blues”

31. EVENTIDE PITCH FACTOR
The Pitch Factor provides 10 of Eventide’s best and most popular Harmonizer effects and even includes some of the same presets found on Eventide’s studio rack processors used by players like John Petrucci, Steve Vai, Joe Satriani and Brian May. Eventide’s natural-sounding harmony effects have never been more affordable. HEAR IT: Dream Theater, “Misunderstood”

30. ROGER MAYER OCTAVIA
Roger Mayer designed fuzz boxes for Jimmy Page and Jeff Beck during the mid Sixties, but he is best known for his association with Jimi Hendrix. Mayer completed the Octavia, which doubles audio frequencies to produce tones an octave higher, days before Jimi went into the studio to record “Purple Haze” with it. The rest is history. HEAR IT: Jimi Hendrix, “Fire”

29. UNIVOX UNI-VIBE
Another crucial element of the Jimi Hendrix sound, the Univox UniVibe was designed to duplicate the rotating speaker effect of a Leslie cabinet. Actually its distinctive thick, watery, warbly effect sounds more like a unique combination of phase shifting and chorus that many guitarists think sounds even better than a Leslie. HEAR IT: Robin Trower, “Bridge of Sighs”

28. DALLAS ARBITER FUZZ FACE
The Fuzz Face became a legend mainly due to the prominent role it played in shaping Jimi Hendrix’s distorted guitar tone. Originally built between 1966 and 1975, the Fuzz Face was resurrected by Jim Dunlop in 1993. Dunlop’s Jimi Hendrix Fuzz face faithfully reproduces Jimi’s 1969 silicon-transistor version of the pedal. HEAR IT: Jimi Hendrix, “Foxey Lady”

27. MXR FLANGER
Introduced in 1976 the MXR Flanger was one of the first pedal flangers to hit the market. With its thick, jet-like swooshes and studio-quality low-noise performance, it’s still one of the best flanger pedals money can buy. HEAR IT: Van Halen, “Unchained”

26. BOSS OC-2 OCTAVER
Chorus is one way to thicken a guitar’s tone, but many players think that an octave divider like the Boss OC-2 is even better. The OC-2 produces additional tones one and two octaves below the original signal, making the sound heavier than a hippo on a burger binge. HEAR IT: Joe Satriani, “Super Colossal”

25. DAN ARMSTRONG ORANGE SQUEEZER
This micro-sized box, which plugs either directly to a guitar or amp, has only an on/off switch, but when it comes to sweet, smooth, singing compression sounds, it’s dialed in just right. Many studio guitarists consider it the best compressor effect for guitar. HEAR IT: Dire Straits “Sultans of Swing”

24. MXR CARBON COPY DELAY
The MXR Carbon Copy is one of the first pedals Way Huge founder Jeorge Tripps designed when he joined forces with Jim Dunlop, and many guitarists consider it the finest analog delay ever made. In addition to providing up to 600ms of delay time and a modulation function, it sounds absolutely god-like. HEAR IT: Stone Sour, “Say You’ll Haunt Me”

23. Z.VEX SEEK WAH
By stepping sequentially through up to eight wah filters with variable midrange settings, the Seek Wah creates an unusual pulsating rhythmic and melodious effect that is part auto-wah, part tremolo. Since its introduction in 1996, numerous effect builders have copied designer Zachary Vex’s innovation, but none sound as wonderfully wacky. HEAR IT: Third Eye Blind, “1000 Julys”

22. BOSS DS-1 DISTORTION
Continuously produced since 1978, the Boss DS-1 Distortion is the second most-popular Boss pedal of all time (topped only by the TU-2 Chromatic Tuner). This humble distortion pedal is the foundation of Steve Vai and Joe Satriani’s solo tones as well as Kurt Cobain’s distorted rhythm guitar sound on Nevermind. HEAR IT: Steve Vai, “The Animal”

21. MU-TRON BI-PHASE
Featuring two independent phase shifters in a huge, oversized box, the Bi-Phase creates unique stereo and two-speed phasing effects with a thick, swirling sound that many have futilely attempted to duplicate. In addition to standard phasing sounds, the Bi-Phase generates impressive, realistic rotating speaker effects when used in a stereo setup. HEAR IT: Smashing Pumpkins, “Starla”

20. BOSS DD-3 DIGITAL DELAY
Boss DD Series pedals placed the sophistication of rack-mounted digital-delay effects in a stomp box. The DD-3 considerably reduced the price of a digital delay unit, making the effect affordable for everyone. It’s remained a high-performance workhorse for cash-strapped gigging guitarists since its introduction in 1986. HEAR IT: Jane’s Addiction, “Mountain Song”

19. Z.VEX FUZZ FACTORY
Like a Fuzz Face that’s OD’d on a cocktail of speed and LSD, this unapologetically over-the-top fuzz box produces some of the grittiest, nastiest and most mindblowing distortion tones known to mankind. The Stability control can produce self-oscillating feedback that bends pitch when you tweak the knob. HEAR IT: Muse, “Plug in Baby”

18. MAESTRO ECHOPLEX
Introduced in 1959, the oversized, cumbersome Echoplex used a loop of tape and several recording heads to produce echo, delay and sound-on-sound layering effects. It was the most elegant way to duplicate studio delay effects before engineers figured out a way to produce them with analog or digital circuitry, and many players still think tape echo sounds best. HEAR IT: Queen, “Brighton Rock”

17. DALLAS RANGEMASTER TREBLE BOOSTER
This misnamed pedal actually cuts bass frequencies instead of boosting treble, but more importantly it also boosts the gain in front of the amp and enhances a guitar’s midrange, which led to the delicious distortion tones heard on early albums by Black Sabbath, Queen and Rory Gallagher. HEAR IT: Black Sabbath, “Paranoid”

16. FULLTONE OCD
There are more than 2,000 overdrive pedals on the market today, so when a relative newcomer like the Fulltone OCD becomes instantly popular, you know it’s good. The OCD makes good tone great and great tone amazing by enhancing harmonic overtones and making a guitar’s natural tone more punchy, dynamic and ballsy. HEAR IT: Paul Gilbert, “Eudaimonia Overture”

15. MXR SIX BAND GRAPHIC EQ
Players like Eddie Van Halen and Dimebag Darrell used this device as a secret weapon to boost mids and increase the gain of the signal hitting their amps. The original blue version had no on/off switch, but its tones are so sweet you wouldn’t want to turn it off anyway. HEAR IT: Pantera, “Cowboys from Hell”

14. MU-TRON III
When it comes to envelope follower effects, the Mu-Tron III is the big, pimpin’ mack daddy of them all, producing auto-wah effects that are funkier than a Cadillac Eldorado with leopardskin seats and gold-plated spinning rims. From duck-like quacks to synth-like swells, the Mu-Tron III produces unlimited funk for your buck. HEAR IT: The Grateful Dead, “Estimated Prophet”

13. GIG-FX CHOPPER
What the Whammy did for pitch shifting, the Chopper’s treadle-controlled tempo does for tremolo/chop, rotating speaker and panning effects. As a result it’s much more than an ordinary tremolo pedal, capable of creating unique effects that can sound like chattering insects or helicopters getting sucked into a black hole. HEAR IT: Tool, “Wings for Marie (Part 1)”

12. ELECTRO-HARMONIX SMALL STONE
The intense swirling swoosh of a Small Stone is usually what comes to guitarists’ minds when someone mentions a phase shifter. The Small Stone made phase shifting affordable, but even players like David Gilmour who could afford anything they wanted couldn’t resist placing a Small Stone in their rigs. HEAR IT: Radiohead, “Paranoid Android”

11. BOSS MT-2 METAL ZONE
Love it or hate it, the Boss MT-2 Metal Zone provided a simple stomp-box solution for guitarists who wanted to duplicate the intense, highly saturated distortion tones and radical EQ settings of Metallica, Megadeth and Slayer. Since its introduction in 1991, the Metal Zone has become one of Boss’ top-five best-selling pedals. HEAR IT: Megadeth, “Captive Honour”

10. BOSS CE-1 CHORUS ENSEMBLE
Introduced in 1976, the Boss CE-1 Chorus Ensemble is the pedal that introduced most guitarists to the jangly sounds of chorus. Designed to replicate the thick sound of a double- or triple-tracked guitar, chorus took on its own life and became a defining guitar sound of the late Seventies and early Eighties, when players like Alex Lifeson never bothered to turn the effect off. HEAR IT: Rush, “La Villa Strangiato”

09. A/DA FLANGER
Many consider the A/DA Flanger the ne plus ultra of pedal flanging effects because it accurately replicates the deep sweeps of genuine tape flanging. A bonus is its “auto-whammy” effect that bends pitch up and down, which has long been part of Paul Gilbert’s trick bag, as well as its rich chorus effects. The A/DA Flanger was reissued in 2009. HEAR IT: Pat Travers Band, “Boom Boom (Out Go the Lights)”

08. ELECTRO-HARMONIX DELUXE MEMORY MAN
This analog delay is somewhat primitive by today’s modeling standards, but its warm, lo-fi echo sounds are so rich and musical that players still prefer it to many digital delay units. The pedal also creates crude chorus and quirky vibrato effects that sound unlike anything else. Back in the day, The Edge’s setup consisted of just a Memory Man and a Vox amp. HEAR IT: U2, “A Day Without Me”

07. MXR DYNA COMP
The MXR Dyna Comp has long been the secret weapon of many Nashville guitarists, but you don’t need to be a chicken picker to appreciate the way it brings subtle nuances up front and tames aggressive pick transients. The Dyna Comp also makes clean tones warmer and fatter, and it provides nearly endless sustain when paired with a distorted amp or an overdrive pedal. HEAR IT: The Police, “Walking on the Moon”

06. VOX V847 WAH
At one point in the Sixties, a Vox wah and a Cry Baby were the same thing, but they began to develop their own identities. The Vox V846 (reissued as the V847 in the '90s) features a chrome-plated treadle, and it has a narrow, throaty midrange that some players, including Eric Clapton, Jimi Hendrix and Stevie Ray Vaughan, found more expressive than the Cry Baby’s wider range. HEAR IT: Cream, “White Room”

05. ELECTRO-HARMONIX BIG MUFF PI
As this pedal’s name suggests, the Big Muff sounds hairy, meaty and juicy, providing boosted bass and maintaining note definition when playing chords. Players like Robert Fripp, David Gilmour and Carlos Santana made the Big Muff legendary during the '70s, and it enjoyed a resurgence in the '90s when Smashing Pumpkins and Sonic Youth rediscovered its gritty glory. HEAR IT: Pink Floyd, “Young Lust”

04. MXR PHASE 90
As far as phase-shifting effects go, the sound of the MXR Phase 90 is somewhat subtle and subdued, blending organically with a guitar’s tone (instead of dominating the way other phase shifters do) and providing a slight treble boost. The Phase 90 is a crucial element of Eddie Van Halen’s classic brown sound, and you can hear it on almost every solo on the early Van Halen albums. HEAR IT: Van Halen, “Eruption”

03. DIGITECH WH-1 WHAMMY
The DigiTech Whammy was the first stomp box to allow guitarists to continuously vary pitch with a treadle pedal. This ingenious device is like an instrument unto itself, and it’s become a favorite of adventurous players across the spectrum, including Tom Morello, The Edge, Dimebag Darrell, Trey Anastasio, Matthew Bellamy, Buckethead and Jack White. HEAR IT: Rage Against the Machine, “Killing in the Name”

02. DUNLOP CRY BABY WAH
The Cry Baby wah dates to the '60s, when it was a product of the Thomas Organ Company (which distributed Vox gear in the US). Jim Dunlop started making Cry Baby wahs in '83 when Thomas ceased business, and the Cry Baby wah has become a best-selling pedal. The design has changed, but the emotive, vocallike sound of a Cry Baby has never gone out of style. HEAR IT: Guns N’ Roses, “Sweet Child O’ Mine”

01. IBANEZ TS9 TUBE SCREAMER
Originally produced between '82 and '85 and reissued in the '90s, the TS9 Tube Screamer is the most popular overdrive pedal. Purists may prefer its predecessor, the TS808, but rock, punk, metal, blues, funk and R&B guitarists agree that a TS9 significantly improves tone. SRV used a TS9 to boost the signal hitting his amps, and Kirk Hammett loves the midrange growl it gives his solos. HEAR IT: Metallica, “Seek & Destroy”