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 Evil Twin module.  It compares to the Lovetone Doppelganger.

Lovetone built a selection of outstanding, high quality boutique pedals in the small town of Henley-On-Thames from 1995 to around 2001.  During that time, they managed to set the pedal business on its ear with their imaginative designs sporting lots of controls.  Their Doppelganger was no exception.  At its heart is a 4-stage optical phaser.  What's unique is that the phasing is controlled by two separate LFO circuits, along with a variety of controls for the wave and tone.  There were two versions of the Doppelganger, the second adding an extra slow control and square wave control to LFO 1, along with a direct out jack.  Our GT Evil Twin compares to the second version of the Doppelganger.  It has the same great audio circuit, but with a few tweaks to simplify its usage and complexity without losing any of its sonic goodness.  The Doppelganger has been used by numerous artists including The Edge, Jimmy Page, members of Radio Head, Kirk Hammet, Johnny Marr of The Smiths, and others.  The originals were pricey for their time, and the low production quantities and their popularity make them pretty expensive, although not too difficult to find, today.

With the dual LFO design and numerous controls, the range of phaser/vibrato effects you can create defies description.  With the possible exception of when the Rates are set to their highest, almost every combination of settings could reasonably be used.  There aren't a lot of "spacey" or "seasick" settings to avoid.  It is tempting to describe most of the available tones as "subtle", but that's not quite right.  They can be very distinctive and obvious.  You won't get those extreme, over-the-top phasing sounds, or the jet whoosh, though.  It might fit in best with music that is slower and has some space between notes to allow this effect to shine - blues, country, ballads, folk, pop/classic rock, psychedelia ala Pink Floyd should all be great.  However, you'll need to carefully note your favorite settings so you can get them back.  For phasers, this one is pretty quiet as long as you don't allow too much noise into your input signal.  The sound is obviously going through some filters, but the result is very pleasant and "clean-sounding", giving you the feeling you are definitely playing a quality effect.  You can probably overload it and get some distortion - maybe you want to, maybe you don't - but it "plays warm and clean".  It's similar but different from a Univibe (our SwirlOVibe), but you might use it for the same types of music and in a similar manner.  A very cool and addictive effect, for sure.

While our Evil Twin gives you all the tonal options of the Doppelganger, we have made changes to some of the connection options to better fit into our rack-based line of modules.  Even after these changes, the Evil Twin is still one of our most complex and widest modules at 3" with a dozen or so controls.

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