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!


I hope all is going well for you!

I’m back in the USA now, after a lengthy time away.  I’ve taken a bit of time to survey the post-post-COVID business climate and think about our next steps.   As is often the case, there are conflicting signals to sort through.  I won’t bore you with all the details.  The result is that I think the time is still not right to resume normal operations. 

One of the primary reasons is personal.  About a year ago I jumped into a really fun, non-work opportunity that took me out of the USA for most of the past year.  I will be out of the country again most of the coming year before things settle down to a new normal for me.  It’s a lot of fun, but wasn’t really part of any plan I had, so I need to adjust my plans.  I’m not able to operate Gerlt Technologies while I’m away, so the shutdown will continue for probably another year due to that until I can get my personal and professional plans realigned. 

Beyond that, the post- post-COVID situation is still unsettled.  I expected a period of ripple effects from COVID shutdowns, supply chain problems, and other world economic and political events that impact our business.  I’m starting to think those ripples aren’t going to die away and return us to something similar to the world we knew before 2020.  If some of those changes become permanent, much work and difficult decisions may be necessary.  At the moment, the parts I couldn’t obtain are now available, but some others are now unavailable.  Costs are both up and down for components, but shipping costs are now a large and growing portion of component cost and would probably force a general price increase, an action I’m very reluctant to take.  In a market that is difficult to read, it is difficult to justify additional investment.  As long as we remain cautious, we can continue to wait for time and change to bring about a better situation, even if it takes a while.

In the meantime, I will have some time to work on the less exciting “internal stuff” that is necessary to the process of building and delivering our products.  Our internal processes are a bit messy as a result of rapid product line growth, shutdown of some suppliers and vendors, and other reasons.  If we were to resume taking orders, these problems would quickly tangle up our operations.  So while we have “quiet time”, I’ll work to clean up some of those issues so we’ll be better positioned for the future.

I hope to also be doing some of the fun work, such as completing some new products, or at least moving them further along, and possibly some marketing events.  So keep an eye on us while we work through some of the issues that are holding us up at present.  I’m not sure exactly when I’ll return from my next sojourn, but it will likely be about this time next year when I pop up and take another look around to see how it looks.

Until next time,

Bill Gerlt

President, Gerlt Technologies

Dallas, Texas

21 June, 2023




Hello, Effects Fans!

Today we announce our new Earthquake module.  It compares to the Demeter Tremulator, Fulltone Supa-Trem, and Joyo JF-09 Tremolo pedals, which all share a base optical tremolo circuit.

Tremolo is one of the simplest effects.  In its basic form, it just turns the volume up and down at some rate.  The depth is simply how loud and how close to silent it gets as the volume adjusts.  Deeper and faster tremolo can produce choppy, helicopter sounds, like the intro in Green Day's Boulevard of Broken Dreams.  Medium to low levels of depth at slower speeds can yield classic Creedence Clearwater Revival tones or give you some cool, subtle movement in your sound.  The Demeter Tremulator is considered by many to be the best tremolo pedal ever produced.  It has simple controls for a simple effect, just Depth and Speed.  The Joyo JF-09 is similar.  The Fulltone Supa-Trem adds a few extra controls to let you tweak your tremolo effect, but is essentially the same circuit as the other two.  Our Earthquake module compares to all three of those tremolo pedals.  It comes in three base configurations that differ primarily in the controls that are included.  Note that the Danelectro Tuna Melt also sounds and works similarly, but the circuit is just enough different that it isn't covered by our Earthquake module.

Overall, this is a very nice tremolo, pleasant and warm.  Ours is quieter than the stock Supa-Trem pedal we compared with.  There is no distortion if you have the Volume set properly, although our test Supa-Trem pedal does have bits of distortion or clipping now and then.

All the controls and optional controls interact to some extent, so you may have to fiddle around a bit to dial in the exact sound you want.

Without the external Volume control or internal volume trimmer, the volume in the circuit is set to a fixed level.  That level is generally OK, unless you use settings near the max or min for Depth and Speed.  Then it might be a bit above or below unity volume.  The Volume control lets you set your unity volume level.  Volume on a tremolo is a little funky.  Depending on your wave shape, Rate, and Depth, you are changing the amount of time the volume is cut, as well as the amount it is cut, affecting the perceived volume.  This usually isn't an issue with "normal" settings, but may cause lower/higher volume at some extreme settings.  Set it where you need it, of course.

Depth has a a good range, skewed more toward the shallow end, allowing good control over more subtle settings.  With the Hard/Soft switch set to Hard, higher Depth settings get very choppy.  Depth can be smoothed out with the Bias control when the Hard/Soft switch is set to Soft.

Speed also has a good range, although it probably goes faster at the max than is necessary.  The Half Speed switch option gives you a range of slower speeds and better control over them.  We do the Fast/Slow switch a little differently from the Supa Trem pedal,  Ours will tend to have a slightly lower max speed, although it seems unlikely anyone would use it near those max speeds anyway.  We've included a blinking Rate LED, too.

Bias changes from the Hard default wave shape to a range of smoother wave shapes when you have the Hard/Soft switch set to Soft.  This control isn't used when the Hard/Soft switch is set to Hard.  Setting the switch to Hard is the same as turning the Bias pot all the way one direction.

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