Using Pedals with Amp Modelers

An amp modeler is a device that reproduces the sound and behavior of a guitar amplifier, either in a multi-effects floor unit or in a single pedal. Some, like the Strymon Iridium, were "designed as an amp modeler solution in a pedal format that you can drop into any pedalboard"¹. Others, like the Atomic Amplifire, combine amp modeling with a full multi-effects engine in one box². A third group, including Origin Effects' RevivalDRIVE Compact, are analog circuits that model an amp's preamp and power amp behavior rather than sampling or digitally emulating it; Origin Effects says of its Amp Recreation pedals that "their real identity is as analogue amp modellers"³.

The question for a pedalboard builder is where the modeler sits in the chain, and what happens to the pedals on either side of it. This page covers the four common configurations: pedals into the front of a modeler, pedals in a modeler's effects loop, direct rigs with cab sims and impulse responses, and parallel routing around the modeler. For the broader question of what goes where, see pedal signal chain order.

What an amp modeler is and where pedals fit

Amp modelers fall into a few families, and the family determines how your pedals interact with it.

The distinction matters for pedal placement. Origin Effects treats its analog modelers as an amp in the chain, with the same before-and-after logic you would apply to a real amplifier³. Digital units like the Amplifire often include their own effects sections, so your external pedals may only need to cover what the unit lacks². And some pedals blur the line: the Behringer AM400 Ultra Acoustic Modeler is a modeling effect pedal built for electric players who want an acoustic guitar sound, a specialized case of amp and instrument modeling⁷.

A related category is the AB/Y switcher, such as the KMA Machines AB/Y series, which splits, combines or switches between audio devices. These are useful when a modeler is one of two destinations for your signal, for example feeding both a modeler and a real amp⁸.

Pedals into the front of a modeler

Running pedals into the front of a modeler mirrors running them into the front of a real amp: drives, fuzzes and boosts hit the modeler's input stage and push it the same way they would push an amplifier's preamp.

• Carl Martin describes its Ampster preamp pedal as usable "as your main overdrive pedal into a clean amp, as a preamp into a power amp or effects return, or as a core tone shaper before modulation and delay"⁹. The same logic applies to a modeler set to a clean amp model.
• Master Effects says its preamp pedals "were designed to be used in front of an amplifier" but have enough output to drive a power amp or FX loop return, though performance in that use is not guaranteed¹⁰.
• Horizon Devices built its Apex Preamp to be "voiced to cut through both high gain heads and integrate perfectly with digital modeling rigs," a preamp designed from the start to sit in front of a modeler¹¹.
• Mod Electronics' Penetrator "adds glistening harmonics that get loud enough to saturate your amp's front end," a boost-style pedal whose purpose is exactly this front-end push¹².

One placement note from Origin Effects: "For players using an amp-like overdrive pedal, it can be very useful to place the compressor after the overdrive." Placing the compressor after an amp-like overdrive preserves the guitar's volume control over the overdrive level and keeps your level consistent when you clean up¹³. The same article adds that certain vintage fuzz and wah pedals do not work with buffers and should go before buffered tuners and before the compressor, a caveat covered in more depth in true bypass and buffers¹³.

Pedals in a modeler's effects loop

Many modelers, like many amps, provide an effects loop: a send and return placed after the amp modeling, where time-based effects normally belong. The routing tools built for amp effects loops work the same way here.

• The American Loopers Amp Effect Loop Switcher reroutes any effects connected to its PEDALS SND and PEDALS RTN jacks to run through the loop or to the front, and can also be used with amps that have no FX loop by sending everything to the front without disconnecting anything¹⁵.
• The Saturnworks Front / Effects Loop Switcher does the same job in a simpler form: "In one switch position, your pedals go to the front of your amp. In the other position, your pedals go through your amp's effects loop"¹⁶.
• The JHS Pedals Blender is a parallel blender with a send and return loop: "Take any effect or chain of effect (even your whole board) and run them through the send and return of the Blender." It can also serve as a tuner out or simple effects loop to activate a string of pedals for a preset tone¹⁷.

For the underlying technique of connecting a pedalboard to an amp's loop with four cables, see the four-cable method.

Several pedals exist to manage what runs in the loop and what runs in front of the amp. The American Loopers Amp Effect Loop Switcher reroutes any effects connected to its PEDALS SND and PEDALS RTN jacks between the amp's FX loop and the front of the amp, and it also works with amps that have no FX loop by sending all effects to the front without disconnecting anything¹⁵. The Saturnworks Front / Effects Loop Switcher does the same job: in one switch position your pedals go to the front of the amp, in the other they go through the amp's effects loop¹⁶. For players who want a parallel path instead, the JHS Pedals Blender runs any effect or chain of effects through its send and return, and it can also serve as a tuner out or simple effects loop that activates a string of pedals at once for a preset tone¹⁷.

Stereo direct rigs and impulse responses

Two things complete a direct rig: the cab stage and the output path.

Cab sims and IRs. Origin Effects explains that in its P/AMP mode, "the POST-DRIVE EQ is disabled and there is no output filtering. This is used when the Amp Recreation pedal is used directly with power amps into guitar cabs, or with some sort of cab sim"¹⁸. In other words, when going direct, the speaker stage has to come from somewhere: either the modeler's built-in cab block, an impulse response loader, or an external cab sim pedal. GUP Tech's Taxi Cab and Lab Series #16 are examples of the latter; the maker says the Lab Series #16 "will bring any pedalboard tone to a complete 'Micked Cab Tone'"¹⁹. Note the Taxi Cab's limits: it is "NOT an attenuator, its use is to simulate a cab on a Line/Instrument Level only. You cannot plug this pedal between amp and speaker"²⁰. See speaker simulation pedals for the category.

Amp captures. HeadRush's products use Neural Amp Modeler captures, which "recreate the sound, response, and feel of real amplifiers, pedals, and signal chains with exceptional accuracy"²¹. Captures of full pedal-and-amp chains are one way to fold favorite drive sounds into the modeler itself.

Feeding amp and PA at once. The Radial JDX Direct-Drive is "an amp simulator designed for your pedalboard," and Radial suggests you "use the Direct-Drive at the output of your pedalboard to feed your amp and the PA at the same time," a hybrid rig for players who want both a stage amp and a direct feed²². Stereo versions of these rigs are covered in stereo pedal rigs.

Running pedals in parallel with a modeler

Parallel routing splits your signal into two paths, processes them separately and sums them back together. Around a modeler, this lets you keep a clean or modeled path alongside an effects path.

• Saturnworks' Parallel Pedal "lets you set up a simple 2-channel parallel setup with a single combination splitter/summer"²³.
• The JHS Blender, covered above, runs any effect or chain through its send and return and blends it with the dry signal¹⁷.
• Carl Martin's Dual Injection has a dedicated Parallel mode: "connect the Output 1 before your Drive or Preamp, and then use the Input/Output 2 on the side of the pedal to connect to your effects loop on the amp"²⁴. The same wiring works with a modeler's loop, putting one side of the parallel path after the amp modeling.

The Poly Effects Ample

The Poly Effects Ample is an amp simulation pedal offering "a curated collection of classic amp tones in an easy to use format"²⁵. The maker positions it as flexible rather than amp-replacing: "Ample can replace your amp or complement it, allowing you to stack gain tones," and it "can run direct to monitors, in ears or headphones"²⁵. Its amp categories include a Clean mode described as "Boutique amps for perfect clean tones"²⁵. For players comparing it with the analog approach, Origin Effects' Amp Recreation pedals are "all-analogue modellers, and as such, we can think of them as an amp"¹⁸, a useful contrast with a digital unit like the Ample.

Pedals on this page

Origin Effects RevivalDrive Compact

Origin Effects · Overdrive

$385 list price

Strymon Iridium

Strymon · Speaker simulation

$399.99 list price

Behringer AM400 Ultra Acoustic Modeler

Behringer · Acoustic

KMA Machines ABY

KMA Machines · Switching

Peavey Rock Master Preamp Pedal

Peavey · Preamp

$199.99 list price

Lehle Parallel SW II

Lehle · Switching

Carl Martin Dual Injection

Carl Martin · Distortion

Poly Effects Ample

Poly Effects · Speaker simulation

$399 list price

Questions