Rack Effect Module Configuration and Customization

With Gerlt Technologies' customized rack effects you have many, many options to choose from when designing your setup.  Your design will have 3 main parts:  Signal Chain, Module Configuration, and Enclosure Configuration.

In addition to those configuration options, we'll also cover some common configuration options and comment on our module groupings.

Signal Chain

When you design your signal chain, you are defining the features you want in your signal chain, from guitar to amp.  You will also be defining the specific paths through whatever effects you need.  If you have ever used guitar pedals, you have already designed signal chains, even if it is as simple as guitar, cable, pedal, cable, and amp.  We won't go into the myriad considerations and details of that activity here.  There will be articles in the More Info section of our site to help with that.

Module Configuration

As you design your signal chain, you will be selecting which GT effects modules you will be using (at least we hope so!).  In most cases, you will quickly find that picking modules will lead to a need to sort through available configurations and options of the selected modules.  Some modules have very few configurations or options, while others have a large number of configurations and options.  The product descriptions for the individual modules contain the details about the configurations and options available for each module.  Following are some general recommendations, guidelines, and useful information to help you select configurations and options that will meet your needs.

While it may be tempting to pile on the options to give you more control over an effect, there can be some downsides to doing so.  The more controls you have, the more difficult it becomes to dial in a specific sound among all the switch settings and adjustment ranges.  Some of those controls may be interactive, making it trickier to find the right combination of settings.  Flexibility can add complexity.  If you can get what you want with one knob, count yourself lucky.  Adding extra controls (or connections) adds mechanical parts to the module.  Mechanical parts such as switches, pots, and jacks will eventually fail with normal use.  Adding controls and connectors adds failure points.  Adding controls and connectors can also result in requiring wider front and rear panels to mount the extra components.  Wider panels take up more space in your enclosure, perhaps resulting in the need for an additional enclosure.  Which leads into another potential downside - increased cost.

If you are familiar with a guitar pedal, you may have a good idea of what you would like to change about that pedal to make it sound better in your setup.  Look for a corresponding GT module on our Compares To page, then look for configurations and options that provide that type of modification.  Some modules have a large number of configurations and options.  Pick the configuration first, then select options based on customizations of interest.  We can't test every possible combination of configurations and options, but we note incompatibility issues, either technical or functional, that we are aware of.  Please watch for compatibility conflicts in your selections, and don't hesitate to ask if something isn't clear.  We will go through all your configurations in detail before your order is placed.

Think about current and future use as you select configurations.  Some effects are best with single coil or humbucker pickups, or certain types of amps.  Some effect features may not be audible or may not sound like you want due to your choice of guitars, amps, music style, playing style, and other effects in your chain.

We don't have audio clips available to demo our effects.  Eventually we will.  But even when we provide them, don't rely overmuch on them.  Consider the following.  Probably you have purchased numerous guitar pedals, likely without the ability to try them in person first.  Some you probably researched on YouTube or other sites where you could hear clips.  You've probably found some number of the pedals you bought didn't work out and you sold them or booted them off your pedal board.  How many of the "bad" ones did you hear online demos of?  It's unclear that online audio clips or demos end up being good indicators of whether a pedal will work out.  In the end, you don't know until you play it in your rig.  But chances are that you have tried a lot of pedals in your rig, some you kept and some you didn't.  For the ones you still use, you know their configs and what works for you.  For the ones you dumped, you probably know what the problem was - too muddy, too bright, too aggressive, not aggressive enough, not enough control in the Tone knob, or 1001 other possibilities.  Both cases, the keepers and the dumpers, give you a good basis for choosing modules, configurations, and options we offer.  Sometimes you can "use your head" after you've already "used your ears" to figure out what might work best for you in your rig.  For example, you might detest Big Muffs with their scooped mids.  But a Big Muff with a mids control and more aggressive cap values in the clipping/gain stages that allows you to cut through the mix better may be the bomb.

Some modules may be just the way you want them with few or no options or changes necessary.  It may be worth considering simple options that expand (as opposed to change) tone options so when that module gets boring next year, you may have an option to change it up a bit and make it fresh again. 

We don't generally offer "multi-effect" modules.  Instead of permanently putting two effects together, we've leaned toward using separate modules instead.  That way, you can swap one of them out easily if you decide you don't need it in the future.  On the other hand, there are modules with options that have a switch that will effectively let you select from two different versions of the circuit, perhaps corresponding to two different commercial pedals.  Those can be cost-effective ways to get a "two-fer".  You won't be switching between two different types of effects, like a fuzz and a phaser you might find in a multi-effects pedal.  Instead you would be selecting between two different fuzzes in one module and two different phasers in another module, which provides a lot of multi-effect combinations.

Here are some parting thoughts on selecting options.  At one extreme, you can select a load of options to get a "tweaker" configuration.  At the other extreme is the "KISS - keep is super simple" approach, a couple of controls that give you most of the usable tone from a circuit.  Both have their pros and cons.  The simple approach makes it easy to dial in the tone you like.  But the tone options are limited.  The tweaker config lets you experiment with a wide variety of options, maybe helping you find the tone you're looking for.  But it is more difficult to dial it in, and it is often the case that after the first weekend, you'll only use a small number of those options in the future. 

There are some points between the extremes, however.  Some pedals lack basic functions that would make them easier to use and provide some very basic options.  You know those pedals - the ones without a Volume or Tone control or some other simple function that would be nice to control in your signal chain.  Those sorts of options are good candidates.  Some pedals you get for a specific type of tone, but the controls are too limited and don't give you some adjustment within the type of tone that you would like.  Options that extend the control or range of control but keep you in the same tone family may be good options.  Perhaps some pedal has always had a feature that you don't like which has kept you from using that pedal.  For example, maybe it is just too bright on all settings.  An option that corrects that deficiency may make that circuit a better match for you, and may be a good choice.

There are a couple of option situations you may want to avoid or at least consider carefully.  One is an option that changes the nature of the circuit's sound considerably.  By their nature, these options are probably outside the intended design.  They may be good at some settings, less good at others.  You may be better off with another effect.  On the other hand, effects aren't cheap, so getting a "twofer" out of an effect can be a better use of your money.  The other type of options to consider carefully are the ones where you don't have a particular goal in mind.  An option may sound like it could be useful "sometime", but will that sometime ever come?  How often would you really use it?

Enclosure Configuration

There are a couple of constraints on enclosure configurations you cannot avoid.  One is that an enclosure holds exactly 17" of horizontal space.  No more will fit in, and you must fill all 17" even if some modules are just "empty" filler modules.

You must also have a "left wing" and a "right wing" module.  Details about Wing Modules.

One constraint you do NOT have is the ordering of the modules between the wing modules.  The physical ordering makes no difference to your signal chain.  The order of the modules in your signal chain is determined by the audio cabling.  There is no need to take your enclosure and modules apart to make changes to your signal chain - just change the cabling.

We recommend a Guitar Pass Thru in the left wing position and an Amp Pass Thru in the right wing position.  They allow you to plug in guitars and amps to the front of your rack, which may be more convenient.  But they also have options to add in buffers to counter the long cable runs you may have for guitars and amps.  The buffers don't take up any additional space when added to these modules.

We recommend using our 18V Power to power all your GT modules, but read the safety precaution about it before you decide.

Interesting and useful configs will certainly need to utilize at least one Rack Switch module to add remote switching for the modules.  While the 3-Button Footswitch used with the Rack Switch DIN is not junky, it is also not the 12-Button Footswitch beast used with the Rack Switch VGA.

Most of our modules are either 1.5" or 2" wide.  Ignoring the small number of narrower and wider modules for the moment, with 17" of space available in an enclosure, that means you'll have room for roughly 8 - 11 modules per enclosure, give or take a bit, depending on the widths of the exact modules you choose and the options you add to them.  In your first enclosure, if you start with a 1" left wing guitar pass thru, Rack Switch, 18V Power, and 1" right wing amp pass thru, you'll have 11.5" remaining for effects, roughly 6 modules.  Thus, with one enclosure and common configuration, you might have around 6 effects, which is probably sufficient for light to moderate effects users.  With two enclosures you are adding space for roughly 10 more, for a total of around 16 effects in 2 enclosures, which is in the range of players using more complex effects chains.  Adding even more enclosures can easily provide space for more effects than most players would be likely to use in a single setup, which brings up another point.  You may be able to break a complex setup into multiple effects chains, since it is easier to have multiple chains in a rack than it is to have multiple pedal boards and associated cabling on the floor.  Since your chain is defined by cabling, not the positions of modules in enclosures, you can have portions of more than one chain in an enclosure

You can freely run audio, switch, and power cables across multiple enclosures.  A variety of cable lengths may come in handy.

If you need filler modules to fill out an enclosure, keep in mind that the majority of our modules are either 1.5" or 2" wide.  It's also good to have a variety of filler sizes that you can re-use when you add or change modules.  If you can fit in at least one each of 0.5", 1", 1.5", and 2", you may be able to avoid purchasing additional filler modules when you make a change.  Getting all 0.5" modules will give you maximum flexibility, but you may not like how it looks so much.

Always use at least two power daisy chains so you can balance power consumption on the two channels of the 18V Power module.  They don't have to be precisely balanced, but the transformer manufacturer says keeping them more balanced is better for transformer performance and lifespan over the long term than using only one channel.

The Tube Reverb module fills an entire enclosure, so it violates some of the guidelines above.  It comes already installed in its own enclosure.

Module Panel Configuration

There is one aspect of module configuration that requires a closer look - front and rear panel configurations.  As you can imagine, since there are lots of module configuration options, and a wide variety of effects, we can end up with a very large number of arrangements needed for controls and connections in a module.  Mostly, "controls" are on the front panel, and "connections" are on the rear panel.  There are exceptions to both those guidelines, but we'll ignore that for most of this discussion.  The product descriptions for each module have information about their panel configs, and the exception cases are documented there.  We will also mostly ignore Wing Modules configurations here.  They are a special case, but also follow most of these guidelines.

Rear Panels

The majority of our modules have what we call the "standard" rear panel configuration.  "Standard" means they have an audio input jack, audio output jack, footswitch jack, footswitch override switch, DC power jack, and DC power indicator LED.  Some may have an extra footswitch/override switch pair or two to support multiple footswitchable options.  Many of our signal routing modules have completely different connection options.  The standard connections can fit into a 1.5" panel, which is the minimum size we generally support for an effect module.  That means the rear connections are generally not a constraint on the width of a module.  We have standard (and non-standard) rear panels in a variety of widths.  It will rarely be the case that you need to worry about rear panel configurations when you are customizing a module - we will almost certainly already have in stock any rear panel you may need.

Front Panels

Unlike the rear panel connections, there is no standard set of controls for modules.  In fact, there are many, many different configurations required and possible.  In almost every configuration, some number of LEDs, knobs (pots), and switches are used.  Note that for these purposes, there is no difference between a "Volume" control and a "Tone" control.  Both use a potentiometer (pot) with a knob and take up the same amount of space on the front panel.  The same is (mostly) true of switches.  By convention, LEDs which indicate status are at the top of the front panel.  Below them we group controls with knobs (pots).  Below the pots are switches.  There are exceptions, but that's how we generally arrange them.  LEDs take up little space.  In almost every case, whatever number of LEDs is required (usually 1), they will all fit in a single row along the top.  Since nearly every module has at least one LED, we just reserve that one row of space for them.  Since they take up the same space and location, they have little impact on the front panel configuration and we'll ignore them for the remaining discussion.

That leave us with some collection of pots and switches on the front panel.  Pots and switches take up about the same amount of vertical space.  Each panel has room for up to 4 vertical spaces for them.  Switches are narrow, so we can often fit 2 switches into a single space.  So for a normal 1.5" wide module, there are 4 spots available for 1 pot or 1, maybe 2, switches.  If your effect module needs more controls than that (many do), then the module will require a 2" wide front panel to accomodate another column of 4 spaces.  If more than that are necessary, then the module will be 3" wide to add another column.  Having enough controls to necessitate a 3" panel may be pushing the limit of what is practical for a single module.

In the product description of each module, the controls and connections, along with module widths are discussed.  If you select options that increase or decrease the number of controls, you might end up with a wider (or narrower - very rarely) module.  You can use the guidelines above to get an idea of how wide the module would need to be to accommodate those controls.  There aren't as many options that will affect the number of back panel connections.  The most common would be the need for more than one footswitch to control extra features in the effect - channel selector, boost, etc. 

The tables below show the widths for the majority of normal front and rear panel configurations for left wing, center, and right wing enclosure positions.  The overall module width is the maximum of the front and rear panel widths required, although both panels will be the same width, of course.  Not all configurations are in the tables, and not all the configurations in the tables (particularly front panels) are normally stocked.  Use these just as sizing guidelines (there are exceptions), not indicators of immediate availability.


Rear Panel Widths

Description Left Wing Width Center Width Right Wing Width
standard connections, 1 footswitch  2", 2.5" 1.5", 2" 1.5", 2"
standard connections, 2 footswitches  2.5"  2"  2"
standard connections, 3 footswitches  2.5"  2" 2"


Front Panel Widths

LEDs Pots Switches Left Wing Width Center Width Right Wing Width
1-3 0 0-6 2" 1.5" 1.5"
1-3 1 0-6  2" 1.5" 1.5"
1-3 2 0-4  2" 1.5" 1.5"
1-3 2 5-6 2.5" 2" 2"
1-3 3 0-2  2" 1.5" 1.5"
1-3 3 3-6 2.5" 2" 2"
1-3  4 0 2" 1.5" 1.5"
1-3  4 1-6  2.5" 2" 2"
1-3  5 0-6 2.5" 2" 2"
1-3  6 0-3 2.5" 2" 2"
1-3 6 4 3.5" 3" 3"


Common Configuration Options

There are a number of options that are generally available for most of our modules.  We don't mention all of them in the individual module descriptions unless those options are particularly interesting for that module.  The options listed below may be available - just ask if you are interested.

Extra Footswitches

Many modules have features or options on a front panel switch.  Some of those could instead be connected to a footswitch jack on the rear panel and controlled by a footswitch.  We don't really encourage this since it adds quite a bit to cost and complexity for a module, but if you really need to switch some feature on the fly, there's a good chance we can make it happen. 

Selectable Voltage

Most modules use only one voltage internally.  Increasing or decreasing that voltage may change the amount of clean headroom or distortion, or have other effects that can change the tone.  Some modules have some good options for voltage that will work and are sometimes used with that circuit.  Those options can probably be made switchable, or other voltage options may be available.  "Selectable" means voltage levels selected with a switch.

Sag Voltage

You may be interested in "sagging" the voltage of some effects to simulate a weak battery.  This is a listed option for some modules, but also available for others.

Component Types

We generally use metal film resistors because they have accurate values and reduce noise in the circuits.  Some effects sound better to some ears with carbon comp resistors.  There is no audible difference between metal film and carbon film resistors, but if you want them, we can put them in.  You can select your resistor type.

There are several types of capacitors commonly used in effects circuits, including a variety of film caps, box caps, electrolytic, silver mica, ceramic, and tantalum.  We use what we believe "sounds right" for the effect.  Occasionally an effect will benefit from changing a capacitor type to reduce noise, provide a more accurate value, or change the tone in very subtle ways.  If you have some specific knowledge of the effect circuit and have capacitor technology preferences, let us know.  We generally do not stock expensive, vintage capacitors that may be past their prime, or even expensive modern substitutes.  We think those have little to no audible impact if you are already using the "correct" capacitor type.  But if you want something specific, let us know.

Transistors, diodes, op amps, and other ICs are often a key part of the tone of an effect.  We provide options in cases where substitution is known to produce a variety of good results, in cases where originals are unavailable or expensive, and in a few other cases.  If your preferences aren't options, check with us on making changes.  Component changes of these types may be limited by compatibility of pinouts, voltages, or other technical issues.

Across the range of modules we offer, there are many different types of mods and tweaks offered as options.  If you think you might like one of those options on a module where that option isn't listed, let us know.  We'll look at the feasibility of that option or maybe other ways of achieving the same goal.

Module Categories

We group our modules into categories to make our product information easier to organize and find.  Most of the categories are pretty well understood, but there are a couple of things you may be wondering about.

What are Amp Sims?  These are modules that were designed to capture the sound of specific amps, and the original pedals were probably marketed that way.  There are plenty of other effects that capture the sound of say, a cranked Marshall, but they may be in the Overdrive or Distortion groups.  It's admittedly a thin distinction.

Amp Sim vs Boost vs Overdrive vs Distortion vs Fuzz - what's going on here?  These terms are often applied with loose meanings, as there are overlaps in how they sound at the boundaries between categories.  Often users refer to the end effect they hear.  For example, a Boost may well boost an amp into overdrive or distortion.  Most of our categorizations are probably not too controversial.  But some of our choices between Overdrive and Distortion may be questionable.  This is particularly true with all the options we offer.  An overdrive circuit with a particular option can become a distortion circuit that sounds nothing like the original overdrive circuit.  We kept things together based on circuit similarity.  It makes our configurations and options easier to describe, even if some of the resulting effects are maybe in the wrong category.

Finally, the colors associated with the categories don't matter at all.  The type of knobs we use come in those colors, so we just picked some color schemes to divide things up and provide some visual variety.  You can request different colors (from among the colors we offer) for any module.  It doesn't matter.