What Are GT Rack Effects?

Gerlt Technologies builds a broad range of customized, rack-mounted effects for guitar and bass.  The "GT Effects" collection of articles provides an overview of our offering and describes how it all works.

What exactly are we talking about?  Take dozens, now hundreds, of popular, classic, and rare guitar pedals, redesign them into small rack modules, offer loads of mods and options, give them remote switching, engineer them to last, make them easy to repair and maintain, and price them at a level comparable to quality boutique pedals.  Build ‘em to order by hand in the USA.  That’s what we’re talking about! 


How did we get here...?

Rack effects history rewritten

The first guitar pedals found their way to market in the 60's.  There were only a very few, but they caught on quickly and effects pedals soon became extremely popular, with many, many different types of effects offered as pedals by many manufacturers around the world.  Pedals gained popularity through the 70's, and by the 80's complex pedalboard setups could be seen onstage for top touring bands.  But as the popularity of effects increased, and their use became both more widespread and more complicated during performances, the pedalboard setups became more and more complex.  Complex electronic setups and the grinding punishment of major touring acts do not mix well.  The early 80's found the most successful, deep pocket players migrating to customized rack effects setups.  At that time, there weren't that many rack effects to choose from.  Rack effects were much too expensive for nearly all players.  Many rack solutions in those days (and even now) were actually just normal pedals somehow mounted in a rack, with complicated cabling and switching setups.  The players that could afford these setups could afford all the custom switching and controls, and perhaps backstage personnel to operate them during shows.  That was far, far beyond the budget of almost all guitar players.  And honestly, the solutions weren't really all that great.  For that enormous expenditure about all you really got was the potential of them being a bit easier to use during performances, along with the potential that if something went wrong with it there may be a "backstage" fix that could get you going again or perhaps allow you to switch over to a redundant rack system.


You don't have to be playing for stadium-sized crowds to experience the problems inherent to complex pedalboard setups.  But it was a matter of cost vs market size back then.  The cost of rack effects was still too high for most players, even though more and more players were getting interested in the benefits of rack effects.  That's when one of the greatest technology disruptions of all times occurred.  Digital technology became available, in mass, to the masses.  In the early 80's, the IBM PC, the compact disc, and other products and related technologies erupted into the marketplace, forever changing the course of our lives and history.  And it changed the course of rack effects just as it did almost everything else.


Digital was "uber cool".  It seemed to offer limitless possibilities.  In the world of audio, digital technology promised the virtual end of analog noise in recordings and playback.  Everything could be pristine and clear to our ears.  It had an immediate effect on the entire audio industry.  But digital had one drawback that many didn't realize or care about at the time - it consumed more power.  Digital effects would eat batteries in no time at all.  As digital effects offered more capabilities, power needs increased.  And while it is difficult to remember that far back, digital technology back then wasn't as tiny as it is now.  The result was increasingly complex digital effects that required more power and took up more space than a pedal format could accommodate.  But they were a perfect fit for racks, particularly racks in studios that were adopting digital technology "whole hog".  And that's pretty much what happened.  Rack effects went digital, got increasingly complex, remained expensive, and found their place in studios.  Somehow the analog effect pedals were no longer cool.  The migration of analog effects pedals to racks died a quiet death in the Digital Era.  Since there wasn't an available and affordable path forward for digital effects for most players, the pedal market stayed analog.


That's the way it has been for many years.  You can get great analog pedals in a bewildering array of types and brands, or you can spend a small fortune to get into digital studio effects.  Digital technology has progressed to the point where power and space requirements aren't what they once were, so digital pedals are becoming available.  They tend to require their own power adapters, a further complication to pedalboards.  There is still a robust market for analog pedals, and more manufacturers than ever.  That is driven in part by the fact that some don't find digital audio processing to sound as good as the older analog technologies.  That's a matter of opinion that varies widely, of course.  Mostly, though, it is the same issue as it always was - cost of pedals vs cost of rack effects.  The digital effects get better, or at least more complex all the time.  As a result, the price never really comes down - you just get more for your money, if you have that much money in the first place.


So how does Gerlt Technologies fit into all of this?  We have a decided preference for analog technology when it comes to music.  But we were tired of all the hassles of using pedalboards.  We wanted what we think might have become available if digital technology hadn't come along when it did.  If that disruption hadn't happened, we think many, many analog pedals would have emerged in rack format.  With the consolidation of many of the old pedal companies into a much smaller number of larger manufacturers, we think that somewhere along the way a more modular form of rack effects would have emerged.  So we went back to that point in effects history and took that approach instead.  We developed modular rack effects that take up much less space, are much more affordable, and have many other benefits over pedals.  Then we spent years developing a huge variety of rack effects modules for players to choose from.  We now offer hundreds of different effect module configurations in a modular rack format, nearly all of which can be customized to your tastes.  That's what we think would have become available if digital technology hadn't changed the effects industry when it did.  It took us a long time, and a lot of effort, but we now have an alternate vision of the effects industry, which is available to everyone, at prices comparable to pedalboard solutions, with benefits we think are superior to pedalboard solutions or other rack effect offerings.

How Do Rack Effects Work?

Of course, we're talking about GT rack effects, so we'll use one of our demo racks as an example.  It is a full gigging setup with several of our effects and some third party rack products added in.  The effects are ones you might choose if you are a David Gilmour fan.  This setup includes enough of our products to illustrate the highlights of our solution. 


Example full setup


Rack close-up, showing third-party Furman power, Korg tuner, and ISP Decimator noise reduction units above three 3U GT enclosures and a rack drawer at the bottom


The other articles in this collection go into more detail on specific features and will probably make more sense after the overview below, so let's get to it!

What do we mean by "a broad range of customized, rack-mounted effects for guitar and bass"?

Broad range of rack effects

There are hundreds, even thousands of guitar effect pedals available, from used vintage units to newer commercial offerings.  They fall into numerous categories - boost, overdrive, fuzz, delay, flanger, chorus, etc.  All those thousands of pedals have their fans, but there is a much smaller subset of them that are "classics" or "standards" which are widely used and have been for years.  Famous riffs, songs, albums, and even artist careers have been defined in large part by some of those classic effects.  Our product line-up includes our versions of many of these very popular effects.  We also offer our versions of some of the great rare and expensive effects that would likely also be very popular if only there were more of them, more affordably priced.  In addition, we offer some effects that we think are either under-rated, overlooked, lesser known, or just plain cool for some reason or another.  The pedals in the pictures below are a few of those listed in our Compares To page and are among the hundreds covered by our offering.  Most of our effects are analog, built with tubes, transistors, op amps, and other analog components.  We do offer a few digital effects, and have more on the drawing board.


Some fuzz pedals


Some delay, phaser, flanger, chorus, tremolo, and vibe pedals


Some boost, equalizer, and compressor pedals. 


Some amp simulation, distortion, and overdrive pedals


We don't really keep track of the total number of effects we offer, but it is in the hundreds.  That number places us at the top of the list if you rank guitar effects manufacturers just by the number of effects they offer.  We continue to add more effects to our product line as we get them through our R&D process.  Check out our Compares To page to see a list of our current offerings.  Obviously, even hundreds is still a small portion of the thousands available.  We may not cover every pedal you use, but since we focus on the great and popular pedals, there's a good chance we cover all or at least a good portion of what's on many pedalboards.  As you read on, you'll see that other features of our products makes them more flexible than normal guitar pedals and you may find that even if we don't (yet!) offer some pedal you use, we have an option that would work just as well, perhaps even better. 

Our effects are spread over many types.  We currently have offerings in the following categories:

  • Amp Simulation
  • Boost
  • Buffer
  • Chorus
  • Compressor
  • Delay
  • Distortion
  • Envelope Filter
  • Equalizer
  • Flanger
  • Fuzz
  • Overdrive
  • Phaser
  • Power
  • Switching
  • Reverb
  • Routing
  • Tremolo
  • Vibrato

This list continues to grow.  You can see the list of module types by selecting Products -> Modules -> Modules By Type from the menu bar.  You may notice that in some categories we offer only a small number of modules.  That may be misleading.  Many of our effects have multiple configurations.  Many, many commercially available pedals are the same or nearly the same circuit with some small differences.  We often bundle those similar effects all as one module, with a large number of configurations which compare to many commercially available pedals.  For example, our "Pi" fuzz module comes in dozens of configurations that compare to dozens of Big Muff Pi pedals and Big Muff Pi derivative pedals.  We offer a large number of customizations and options for our Pi module.  Between the base configurations of that one module and the variations you can create with the customizations and options, we can offer hundreds, probably thousands, of versions of our Pi module that compare to many, many commercial pedals based on the Big Muff Pi.  And that is just a single module here at GT.  There are some effects types missing from our current list, but be assured, more effects are on the way.

In our example you will see:


Top GT Enclosure:  Modules for buffered guitar input (Guitar), power (18V Power), remote footswitch (Rack Switch), looper for third party tuner (Looper), compressor (Boa Constrictor), two fuzzes (Woodstock Si-70 and Violet Pi), boost (Color Bomb), overdrive (Blues Booster), another fuzz (British Pi), and distortion (Ben).  In "compares to pedal talk" we might say Klon and Cornish Buffers, pedalboard power brick, pedalboard switching controller, bypass looper, Dynacomp/Ross switchable compressor, silicon Fuzz Face with options, Violet Ram's Head Big Muff Pi, Colorsound Power Boost, Boss BD-2 Blues Driver, Cornish G-2, and Proco Rat.


Middle Enclosure: Modules for flanger (Ms Pinky), equalizer (Tone TwEQer-7), vibrato/chorus (VibraChorus), univibe (Swirl O Vibe), digital delay (Super Nova), and amp output (Amp).  Or Electric Mistress, Boss GE-7 Equalizer, Boss CE-2 Chorus with options, Univibe, and modified tc electronics Nova delay.


Bottom Enclosure: Tube spring reverb. Below that is a drawer for cables and other gear.


Don't see a specific effect you are interested in?  Drop us a line at This email address is being protected from spambots. You need JavaScript enabled to view it.  At any given moment we have a significant number of new products somewhere in the works - research, design, prototype, or test.  We may already be working on what you want.  We're also pretty flexible with our R&D efforts.  If we find there is considerable interest in something we aren't working on, we can certainly look into it and adjust our plans.  Follow us on Facebook "GerltTechnologies" to get periodic updates about our product offerings.

We know you have "your sound", or are looking for it, and providing a wide variety of effects and effect types is necessary to help you make your sound possible.  That is why we offer so many modules and configurations and will continue to expand the list.

Customized Rack Effects

As mentioned above, many commercial pedals are almost identical, modified versions of the same well-known base circuit.  A great example of that is the Electro-Harmonix Big Muff Pi and all the various clones of it that are available.  There is an unknown number of slightly different versions of that pedal that have been produced by EHX over the past several decades.  Dozens of them have been documented.  There are more dozens, probably hundreds, of commercial pedals that are essentially clones or modified versions of the Big Muff Pi circuit.  Some of them include the Guild Foxey Lady, Hohner Tri-Dirty Booster, some Maxon and Ibanez Overdrive pedals, Skreddy Mayo, Blackout Effectors Musket, Sustain Punch Creamy Dreamer, and many, many others.  In addition to all these commercial pedals, there are loads of modifications that can be made to the Big Muff Pi circuit to provide more sonic options than are available from the commercial pedals.  Many of these modified versions are outstanding effects, differing to lesser or greater extent from any version of the Big Muff Pi ever built by EHX.

Even if you aren't really a fan of the Big Muff Pi, you may well be using a pedal that is really just a Big Muff Pi with a mod or two and a new name.  The same is true for many other pedal circuits that are widely available in various forms, such as the Marshall Bluesbreaker, Ibanez Tube Screamer, the Fuzz Face, and the Tonebender.  Many of the top pedal manufacturers got their start by building pedals containing copies or modified versions of those classic pedal circuits (and still do that), producing some great new pedals.  Those little mods and tweaks may be just what you need to convert "a tone" to "The Tone".  That's the essence of the customizations we provide.  They help you find your unique spot in the tone world.

We offer many customizations and options along with our base circuits.  Our circuits and boards are designed to directly support these options and tweaks.  These customizations are not hardware hacks to a circuit, they are designed-in parts of our circuits.  There are many types of customizations available, depending on the effect:  different power voltages, different types of components, extra controls, changes to tone stacks, different ranges of gain, additional clipping options, optional switched components, more/fewer stages, and numerous others.  Some of these customizations are available in current commercial pedals and some are not, or are difficult to find.  Many popular pedal mods are also commercially available - you send in your pedal and it comes back tricked out with new features or otherwise improved over the stock pedal.  We offer many of those mods built in.  And we offer some features and mods that maybe aren't available elsewhere.  We even have entire circuits of our own design.

All this is available so you can get the specific, detailed tone options you need to find your sound.  Perhaps you like the Tube Screamer overdrive, but you aren't a fan of the warm, mids-boosted tone that comes with it.  No problem, we can give you that Tube Screamer overdrive without the mid-boost.  Or we can put the mid-boost on a switch so you can have it when you want it.  Or you like the sound of carbon comp resistors and would like to try them in a Tube Screamer circuit.  Or you want the input and output buffers to be switchable so you can turn your Tube Screamer into a Lovepedal Eternity type of circuit.  Or you would like it to sound more "tube-y", or more aggressive.  Or you want a wider range of gain.  Or you want a bass-friendly version.  Or you need it to cut through the mix better.  Or ...

The options, mods, and customizations we offer can be a bit overwhelming, particularly if you aren't really into all that technical detail stuff.  If you like that tech stuff and know about it, you can easily order customized effects.  If you aren't into all that, you can stick with our standard configurations for each module and be assured that you are getting a good effect circuit without having to sort through a mass of details and options.  If you aren't a seasoned and highly experienced effect user, ordering standard configurations may be the best way to get started.

In our example rack setup you'll see a few of the mods available in some of our effects:


Boa Constrictor compressor with DynaComp/Ross Compressor Option, Ben (Proco Rat) with Clipping Option, and VibraChorus (Boss CE-2 and others) with several options


Some effects circuits cry out for mods and options, so we offer up a good variety of them.  Other circuits aren't so amenable to options, so few are offered for those.  Or you may have a mod in mind that we could build for you.  As long as we can build it in a high-quality manner on our boards, or perhaps even mod our boards to accommodate it, and we can find all the parts we would need, it may be possible.  But it is easy to get carried away.  Check out our Customization guidelines to get some idea of how to get what you need to produce "that tone" you're after, and maybe provide some tonal options "for later", but without creating something so complicated that dialing in those tones becomes difficult.

Rack Mounted Effects

Rack mounting is a defining feature of our effects.  Not only is it a feature in and of itself, but it enables other features by eliminating pedalboard and pedal enclosure constraints. 

There have been rack-mounted effects for decades, so what is special about how we do it?  Ours is a case where a few small things sum up to something bigger than the total.

First, we offer a wide range of effects.  In the past, the commercial rack offerings were limited usually to a single effect or two from a small number of companies, with prices tending to be considerably higher than pedal effects.  If you used a lot of effects, chances are you couldn't build your effects chain using only rack effects.  There just weren't enough available.  You had to mix pedals and rack effects, or just stick with pedals.  Mixing pedal and rack effects generally required extra cable runs to and from your pedalboard and rack - not good!  Or you could stick your pedals in the rack, where they may be difficult to use.

By offering a wide variety of effects and effect types, and by supporting many customizations, we have a huge variety of GT effects available to you RIGHT NOW in rack format.

Another problem with many vintage and current rack effects is that they take up space.  A rack effect usually has to take the full width of the rack, and at least one rack unit or more in vertical space.  Even if you could find, say, the 10 effects you need in rack form, you might be in for an uncomfortably large rack to hold them all.

If you have used rack effects, you probably know about another annoying feature.  Many of them require power adapters that each require their own power outlet.  Those power adapters also have to be secured somehow so they don't come unplugged, dangling and banging around inside your rack case.  Adding insult to injury, many of those power adapters are poorly designed, covering multiple power outlets, taking up more vertical space than the effect unit itself, emitting electrical noise into your signal chain, or cause other unwanted problems.

We take a different, modular approach to racking our effects.  Each effect is a module that fits into a rack enclosure.  The enclosure is 3 rack units high and provides 17" of horizontal space for modules.  Our modules come in different widths.  Most of our modules are 1", 1.5", or 2" wide.  You could have up to 10 or 12 modules in a single 3U rack enclosure.  That's a big saving in space.

You can see modules of various widths in our example racks, including most of our largest modules.


1" Left Wing Buffered Guitar Pass Thru, 2" 18V Power, 1.5" Rack Switch, 2" Looper, (6) 1.5" modules, and 1.5" Right Wing Ben module


2" Left Wing Ms Pinky, 3.5" Tone TwEQer, (2) 2" modules, 6.5" Super Nova delay, and 1" Unbuffered Amp Pass Thru


The 17" Tube Reverb takes an entire enclosure due to its large spring reverb tank and tubes.


Our switching system is also a defining feature of our effects offering.  It is required to make rack-mounting feasible.  GT effects are remotely switched with a flexible, customizable switching system.  The switching system is described in more detail in a separate article on Switching. But for this portion of the discussion, it is important to note a couple of points.  Our switching system does NOT route your sound to the footswitch.  Each switchable module has specific circuitry in it which uses only a simple signal from the footswitch to turn the effect (or a specific feature of the effect) on and off.  Your tone and audio cabling can stay in the rack once it gets there from your guitar and stay there until it leaves the rack modules to your amps.  Our switching isn't limited only to the normal stomp switch on/off switching, although that is sufficient most of the time.  We also have "no switching" modules, "switching optional" modules, and the ability to switch multiple effects on and/or off with a single switch.  If it works for your music and set list, you could setup up switching for "tones", maybe chorus, bridge, verse, or different solos in songs, or whatever "tone units" you might want to create.  The only thing on the floor is a rugged, custom footswitch unit to control your effects.

You can see a footswitch unit with its single cable connected to a switching module in our example:


12-Button Footswitch with cable going to ...


... Rack Switch VGA module


Speaking of the floor, that last bit bears repeating.  Only the footswitch is on the floor.  There are many obvious benefits to that, which are discussed in our Benefits page. 

But you just can't live without your favorite pedal that we don't offer?  Don't worry.  You aren't locked into a rack-only solution from us.  Our solution is completely compatible with your favorite pedals.  There are multiple ways to mix pedals, our effects, and other third-party rack effects, including the usual methods of somehow mounting pedals in racks or running cables between your rack and pedalboard.  We provide a way to better integrate your pedals into the setup - a module that lets you hook your pedals into the switching system so you can remotely control them just like our modules.  That favorite vintage pedal can be switched while safely locked in your rack.  And you can easily cable in rack products we don't offer - tuners, power amps, power conditioners, and high-end noise reduction systems, for example.  This interoperability may provide you a transition path from pedal board to rack effects.  You could even rack mount all your current pedals, using only our switching and routing modules, without using any of our effects modules.  We also offer a handy 3U Pedal Rack to conveniently mount your pedals with easy access to their controls.  We hope you like having lots of options!


3U Pedal Rack


Rack Effects For Guitar and Bass

Of course, we provide modules that work for both guitar and bass.  Bass players have far fewer pedal options, but we try to even it up a bit.  Compared to guitar, the number of commercially available pedals designed specifically for bass is far lower.  That is due in part to the nature of bass.  Some effects get muddy or just don't work well with low frequencies.  Part of the reason those effects don't work well for bass is directly related to the physics and perception of low frequency sound.  There's not much that can be done about that, other than avoid any bad side-effects like loss of clarity or muddiness.  Other effects can cause the rhythm to be lost or diminished.  But some effects don't work well for bass because of limits in the circuit designed to make guitars sound better.  In many cases, bass is reduced or removed so that guitars remain in a certain tone range or to keep the bass in the guitar tone from becoming muddy through some effect.  That can really chop out big hunks of the bass range.  In some of those cases, the circuit can be tweaked for bass.  We offer bass options in some effects that may not normally be considered "bass friendly".  And we offer a unique GT-designed module called Mudslinger that helps normal guitar effects work better for bass.  It lets you keep your root low notes intact so you can bring the thunder, but routes higher notes and harmonics through an effects loop.  Yeah!

Here's a shot of a rack that contains several bass and bass-friendly modules, outnumbering a few guitar modules:


Top enclosure has bass effects (boost, EQ, mixer, two popular overdrives tweaked for bass, chorus). The four modules on the left of the bottom enclosure are popular bass-friendly fuzzes


Rack Effects for the Whole Band

Some effects also work great for vocals, drums, keyboards, and other instruments.  GT rack effects are no exception.  It's easy to combine a few extra effects into a single enclosure with separate effect chains for different instruments or band members.  If you choose to use our 3-Button Footswitches each band member can have his own footswitch controller for his effect(s).  Need to add a reverb to the drums for gigs in small places?  Need a delay on vocals?  Need to add some effects to that vintage keyboard?  No problem!  Depending on your exact needs, that could all be done in a single 3U enclosure with dedicated signal chains and footswitches for each player.



There you have a quick overview of what we offer.  Read on for more details about our technologies and products.  We're excited to be able to offer a broad range of customizable rack effects for guitar and bass.  We think they are a good fit for touring acts of all sizes, maybe particularly for those of you that are looking for a quicker and easier setup and don't have a road crew to handle that for you.  But even if you only play the occasional gig, prefer to jam with your buddies, record in a studio, rock out in your bedroom, or are just looking for an alternative to pedalboards, we think our custom rack effects provide a better alternative to pedals in most situations.  We love pedals, but sometimes they don't love us back, so we've moved on! 


OK, let's talk ...


Rack Effects Cost

Yeah, we know what you're thinking - they're expensive, right?  Don't all these customized rack modules cost a lot of money?  Everyone knows only major rock stars can afford customized rack effect solutions. 

Well, it's true we don't normally give them away.  Our design principles, designs, and final products are all managed in a way to provide flexibility and reduce complexity.  That helps us offset the higher costs of customized rack effect products - not minimize the cost, but definitely lower it from what it might otherwise have to be.  While customization is a contributor to our costs, quality features contribute more.  To us, that's much more acceptable.  You get more for your money, especially over time.  Check out our Benefits discussion to see some of those features that help us deliver a unique, high-quality solution without breaking the bank. 

Our goal is to make our customized rack effects available at costs comparable to a quality pedal board setup.  We're pretty close to that.  It's more affordable than you probably expect.  Check out our Bundle products.  Bundles are possible configurations for all the "other stuff" you need, excluding the effects modules, to get started with our rack effects.  Bundles compare to your pedalboard, power supply, and switching system that players typically have in place.  The Bundles have options you can tweak to your needs and budget, or you can develop your own custom configuration.  The Bundles also make it easier to put together a full setup and figure out the cost.  Once you pick a bundle, then see the pages for individual modules and you will find the costs for each module configuration.  We try to keep the average cost of standard configurations comparable to the cost of good pedals.  At the time of writing, our average standard module configuration is around $225, about what you pay for hand-built boutique pedals. 

Customizations and options can range from free (or in a few cases, even lower costs), or in some cases can add substantially to the cost.  But those are choices you can make.  We believe our standard configurations sound great without additional customizations.  We also believe our customizations are very reasonably priced.  To get a pedal modified, you pay for labor to remove or modify existing components, the cost of new components, and the labor to add the new components, and probably some shipping.  Our customizations are done as we build our modules.  We don't need to undo anything.  Often, the customization parts cost about the same as the parts they would be replacing, so there may be no cost for additional parts or labor.  There is no additional shipping cost if you order your module with the customizations.  Some mods do require extra parts and labor.  But we still don't have to undo anything and there is less labor involved when the customizations are part of the original build.

We build effects so you can make music, the soundtrack of our lives.  We are squeezing down costs so players of all types and budgets can have a rack of GT effects behind them, whether on stage or in the corner of their bedroom.  It doesn't matter what venue you play, you're all rock stars!


Continue to see Benefits of our rack effects