1Tuner
Boss TU-3TC Electronic PolyTune 3Korg Pitchblack
A tuner reads the raw guitar signal directly — before any processing that could obscure the fundamental frequency. Running a tuner after an overdrive or modulation pedal gives the tuner a distorted, pitch-smeared signal to read, producing inaccurate tuning. The tuner goes first, reads the cleanest signal, and mutes the output when you engage it without sending noise through the rest of the chain.
What goes wrong in the wrong position
After an overdrive: the harmonics generated by the drive circuit confuse the tuner's pitch detection, particularly on low strings. The tuner will read and display a pitch, but it will not be accurate.
2Dynamics — Compressor, Volume Pedal
MXR Dyna CompBoss CS-3Ernie Ball VP Jr
A compressor placed early in the chain controls the raw guitar's dynamic range before any gain stages add harmonics. This produces a smooth, even output level that subsequent overdrives and drives respond consistently to. A volume pedal placed here controls the signal going into the drive chain — reducing the signal at this point rolls off the drive amount, which is musically useful.
What goes wrong in the wrong position
Compressor after overdrive: the compressor now squashes distorted harmonics rather than the guitar's natural dynamics. The result is a compressed distortion that loses the pick attack character that makes compression useful in the first place.
John Mayer — uses a compressor before his Tube Screamer, keeping the drive response consistent across picking dynamics
3Wah / Filter
Dunlop Cry BabyVox V847MXR Q Zone
A wah placed before overdrive sweeps the frequency content of the guitar signal into the drive stage, which then emphasises those frequencies. The result is a "vocal" wah quality where the sweep and the drive interact — this is the classic Hendrix and Clapton wah sound. A wah placed after overdrive sweeps the distorted signal itself, producing a thinner, less harmonically rich effect.
What goes wrong in the wrong position
Wah after overdrive: the frequency sweep is applied to an already-distorted signal. The wah effect is audible but more nasal and less expressive — the drive and the wah do not interact, they operate in sequence.
Jimi Hendrix — ran his Cry Baby before his fuzz — the fuzz saturating the wah-filtered signal creates the signature "singing" wah tone
4Overdrive / Boost
Ibanez TS9Boss BD-2Klon Centaur
Overdrive pedals placed before the amplifier push the amp's input stage. The amp's preamp tube clips more, adding harmonic complexity that comes from the amp rather than the pedal alone. This is the Tube Screamer-into-a-Fender-amp relationship that defines John Mayer, SRV, and Clapton's clean boost tones. The TS9's characteristic mid-hump also helps the guitar cut through a band mix.
What goes wrong in the wrong position
Overdrive in the effects loop: the overdrive now sees the amplified signal after the preamp stage and cannot push the tubes into additional gain. The overdrive sounds like overdrive rather than like an amp being pushed. This is a different sound — useful for some applications, wrong for replicating the classic boost-into-amp tones.
Stevie Ray Vaughan — ran his TS808 into a Fender amp with the gain almost at zero and output maxed — the pedal pushes the amp, not itself
5Distortion / Fuzz
Dallas Arbiter Fuzz FaceEHX Big MuffBoss DS-1
High-gain distortion and fuzz pedals typically follow lighter overdrives. A light overdrive before a fuzz can add sustain and compression to the signal entering the fuzz, producing a thicker, more saturated tone. Running a fuzz before an overdrive usually produces a fizzy, uncontrolled sound where the overdrive amplifies the fuzz's noise floor. Distortion pedals can also go before overdrive for different stacking effects — the order affects the compression envelope significantly.
What goes wrong in the wrong position
Fuzz after boost or overdrive: most fuzz circuits — particularly germanium designs — are sensitive to input impedance. A buffered output from an overdrive pedal feeding a germanium fuzz changes the fuzz's clipping character fundamentally, often in ways the player doesn't want.
David Gilmour — uses compression or a boost before his Big Muff in many live setups to control the input and maintain sustain
6Modulation — Chorus, Phaser, Flanger, Tremolo
Boss CE-2MXR Phase 90Boss BF-3Boss TR-2
Modulation effects applied to a distorted signal produce a mushy, undefined chorus or flange — the pitch and time modulation is working on harmonically complex distorted content rather than the cleaner guitar signal. Placing modulation after drive pedals but before delay and reverb means the modulation effect is captured cleanly within the spatial effects, producing a defined shimmer or wobble within a wider reverb tail.
What goes wrong in the wrong position
Chorus before overdrive: the overdrive amplifies and distorts the pitch-shifting artifacts of the chorus, producing a chorus-on-overdrive interaction that is rarely desirable and difficult to control.
David Gilmour — runs his UniVibe and chorus after his drives — the modulation sits on top of the driven sound rather than being distorted by it
7Delay
Boss DD-3TMXR Carbon CopyTC Electronic Flashback
Delay placed after all drive and modulation effects repeats the processed signal — each repeat sounds like the original note with the same overdrive and modulation applied. Delay before overdrive means the repeated signals are individually distorted by the drive stage, producing a cascading distortion effect that can sound compressed and washy. The standard approach is delay late in the chain so repeats decay cleanly.
What goes wrong in the wrong position
Delay before overdrive: the drive stage sees the original signal plus delay repeats, distorting all of them simultaneously. This can produce an extreme, cascading distortion useful for specific experimental sounds — but for all standard delay applications it is incorrect.
The Edge — a notable exception — U2's Edge sometimes runs delay before drive to create the stacked repeat effect. This is an intentional technique, not a mistake
8Reverb
Boss RV-6EHX Holy GrailTC Electronic Hall of Fame 2
Reverb is the final spatial context applied to the entire processed signal. Running reverb after delay means the delay repeats exist within the reverb space — each repeat has the same reverb tail, placing them in the same acoustic environment as the original note. Running reverb before delay means the reverb tail is delayed, which can produce an interesting ambient effect but is generally not what players intend.
What goes wrong in the wrong position
Reverb before delay: the delay now repeats the reverb-saturated signal, producing a very wet, washy sound where the reverb tails are multiplied by each repeat. This is sometimes intentional for ambient music but loses definition rapidly.
Mark Knopfler — uses reverb last in the chain to create spatial depth around his clean Strat tone — the pick attack and note decay are preserved within the reverb wash
The Effects Loop Exception
Most valve amplifiers include an effects loop — a send and return between the preamp stage and the power amp stage. Pedals placed in the effects loop process the already-driven signal from the preamp rather than the raw guitar signal. This changes the effect character significantly.
The conventional approach is to run time-based effects — delay and reverb — in the effects loop. This places them after the preamp distortion, so delay repeats and reverb tails are clean even when the amp is overdriven. Running a delay before the amp's preamp means the preamp distorts both the original signal and the delay repeats simultaneously.
Modulation can go in the effects loop or before the amp depending on the desired result. Drive pedals are almost always better placed before the amp input rather than in the loop — in the loop, a drive pedal cannot push the preamp tubes, which is the primary function of a Tube Screamer or similar boost.