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 Moonquake module.  The GT Moonquake compares to the 4ms Tremulus Lune optical tremolo.

The Tremulus Lune appears to be discontinued from 4ms Pedals, although you may still find a new one here or there.  3ms and Commonsound are earlier names for 4ms Pedals, and some early Tremulus Lune builds show those brands.  The pedal was also sold in kit form and became popular in the DIY pedal-building community, leading to many other "brands" and versions of the circuit, from builders of all skill levels.  Kit builds are sometimes available but may be of widely varying quality.  Even the production builds vary in quality, some of which perhaps shouldn't have been released due to build quality issues.  We've only seen a few of these pedals, all of which had dodgy construction.  The brand new one we purchased for testing is noisy enough to not really be usable, probably from layout and construction issues.   

So how did the GT version turn out?  

First, tremolo is probably the simplest effect there is.  You can do much the same thing by just turning the volume up and down, which is really all tremolo is.  Even in the GT world of customizations, this circuit goes well into "tweaker paradise", with 6 controls instead of the normal 1 or 2.  That's pushing it for regular use, but convenient for when you're searching for "your tremolo".  We like our tremolo simple, so we're a bit at odds with the purpose of this circuit.  Many, many players enjoy this tremolo, so our opinion is just one.

Setting aside the amazing array of controls, how is it?  Well, to us it is still a noisy circuit.  However, there is a Gain control that lets you dial down the gain AND the noise.  To get to "quiet" you have to dial the Gain to "barely on", which might get you below unity volume, or pretty close to it.  Once you dial back the Gain to unity volume or minimal boost, the circuit becomes much more manageable.  We won't attempt to describe the huge variety of tones you can get by adjusting those other 5 knobs to the millions of potential settings.  It's hard to imagine that you can't find your tremolo sound in there somewhere.  Can you find it twice is maybe the more interesting question.

Most tremolo circuits have only a couple of controls, but the Tremulus Lune has half a dozen, most rarely found on any other tremolo circuit.  It's odd to think of that many ways to control volume changes, but they are there.  The Tremulus Lune circuit has some popular modifications that are included.  The first is that external Gain control, instead of the normal internal trimmer.  This makes it easier to adjust for unity volume, or other volume settings for that matter.  The Gain gets pretty high and can lead to distortion if you crank it up.  Cleaner settings are in the "barely on" range of the Gain control.  It is also key to controlling the noise in the circuit.  All those controls are a tweaker's paradise, providing options that we haven't seen in other tremolo circuits.  It can take a while to find settings you like, but maybe also the wide variety of unusual settings will provide you with some unique effects that you enjoy.

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