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!

It has been a while since my last update.  Our status has not changed much.  We are still unable to take new orders.  I’ve personally been off doing something completely unrelated, lots of fun, a long ways from home.  That has gone well, but is taking longer than expected.  Instead of finishing up about now, it appears I won’t finish before late Spring or early Summer.  Our status won’t change before then.

Parts availability and cost were primary causes of our current shutdown.  We use around 6500 different vintage and current production parts to build our rack effects.  It has been difficult to find good vintage parts for a while now, and it gets a little more difficult each year - nothing new about that.  Counterfeit and reject parts flood the market, and prices have soared as caches of legit parts dwindle.  The good news is that vintage parts are often not needed to get great-sounding effects.  Usually there are newer parts that will work as well or better if you can get past the volumes of misinformation and hype out there.  Listen with your ears, not your eyes!

Lack of current production parts forced us to stop taking orders.  Some critical parts do seem to be available again, at an increased price.  We want our rack effects to be affordable, and increased part prices are not helping with that.  For example, one part we use in nearly all of our modules, sometimes several per module, went from about 80 cents to around $5+ each.  Really?!?!  Fakes are also flooding the new parts market to fill the demand of the unwary.  However, a few parts are trending down in price.  In these cases there were too many manufacturers, and none of them were getting enough market share to make larger quantities to help reduce their costs.  Some have gone out of business, leading to consolidation and lower production costs.  We’ll take a cost reduction (and pass it along) anytime we can get one!  I’ll have to sort through our hundreds of effects and countless options to determine any impacts to our pricing.  My goal is to remain comparable to pedal prices.  Or better!

Where does that leave us?  The situation has improved, but we still cannot take new orders.  I’m going to work to finish up my side adventure.  I’ll pop up again, probably around June or July, and see how things are looking and provide another update.  

Best wishes for 2023 !!!

Bill Gerlt

President, Gerlt Technologies

Dallas, Texas

28 January, 2023




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.