Gerlt Technologies makes hundreds of customizable rack effects, at prices comparable to guitar pedals.  It's time to dump that pedal board and get Your Tone off the floor!


 What We Do

You know them as guitar pedals

We build them as rack effect modules you can customize to get Your Tone

Put several rack effect modules into a 3U rack enclosure

Connect power and audio on the back like guitar pedals, adding connections for remote switching

Add a remote footswitch unit to turn rack effects on and off

Add as many rack effect modules, enclosures, and third-party products as you like. Plug in your guitar and amp. Rock it! It's that simple.


Quick Hits:

  • Check out our GT Effects Overview to see why we do this

  • Check out our Compares To charts to see the full list of effects we offer

  • Follow the menus from Products, to Modules, to Modules By Type to get a list of our effect types.  Select any effect type to get a list of all our effects of that type.  Select any effect to get full information including pricing.



Hello Effects Fans!

In my last update I was excited after finding some small quantities of critical components that are needed to build our effects. I hoped that to be a sign that perhaps some of our supply chain problems were easing. But it seems those were just one-off lucky finds. I haven’t found any more since then. On top of all the other problems, we now have the ripple effect of the conflict in the Ukraine, which has caused even more parts to become unavailable and/or very expensive.

It’s one thing to be optimistic, but another to be unrealistic. This is no longer a time for simple optimism. It is a time for handling unpleasant realities. Our reality is that it seems very unlikely that enough positive changes will occur quickly enough for us to re-open in 2022. While the corporation is in a good position to weather a continued lengthy shutdown, the people are not able to. We need to take some time to go do “other stuff” for a while.

We still have several new modules to announce. The work is complete on almost all of them, so I’ll try to get those announcements out in April and May. Other than that, I’m afraid it is going to be pretty quiet here until we are able to reliably source parts at reasonable prices again. I probably won’t have another update until late summer or into autumn.

The good news is that Gerlt Technologies is still here and alive. We haven’t “lost” anything. We still have the largest selection of rack effects available, getting close to 400. Our effects still sound great. And we still want to make them available to you. We’re just going to have to continue our break for a while until the business and economic conditions improve to the point that we can provide outstanding products and support at affordable prices.

I apologize for the continued delay and will do everything I can to get us going again as soon as it becomes feasible.



Bill Gerlt

President, Gerlt Technologies

Dallas, Texas

11 April, 2022




Hello, Effects Fans!

Today we announce our new Swampodillo module.  It has multiple configurations that compare to the Schaller TR-68 Tremolo, the Cesar Diaz Texas Tremadillo, Monster Effects' The Swamp Thang, and the DIY pedal building community's Hearthrob by MarkM.

Sometime back in the 60's, maybe 1968, the German company Schaller started making a tremolo pedal designed to sound like the tremolos in Fender brown face amps.  That was the Schaller TR-68 Tremolo.  It has been out of production for many years, probably since sometime in the 80's when Schaller discontinued a number of product lines.

In the 90's, Cesar Diaz began building his own version of that circuit, which he called the Texas Tremadillo, a quirky tremolo used by some major artists.

Around 2001, Monster Effects released The Swamp Thang, which also utilizes the same circuit.  Other boutique builders have released their versions of this vintage circuit, too.  Builders in the DIY effects pedal community have also based designs on the circuit, including one by "MarkM" called Hearthrob.

Tremolo is a very simple effect.  It is little more than changing the volume by some amount at some speed with a controlling waveform.  Most of the components in this circuit are used just to alter the volume.  Few of them are in the audio path and have any direct impact on the tone, since there isn't really supposed to be any impact on the tone anyway.  So while there are some minor part differences used in the various versions of the circuit, the tone is very similar.  The differences are in the shape of the wave that controls the volume changes.

The GT Swampodillo module comes in four configurations.  Keeping in mind that the part differences are small among all of them, the Texas Thang and Swampodillo configurations are very similar, as are the German Thang and Throbodillo configurations.  Some of the differences are in how the controls work and other minor things that have little impact on the tone.  There are some differences due to the wave shape, though the differences are difficult to quantify and describe.

You can see more details about our Swampodillo module at: Swampodillo.  Or look for it in the Tremolo Modules section under Products -> Modules -> Modules By Type.