The Best Way to Blend Amp Sims in Logic Pro X: A Guide to True Stereo, Mix-Ready Tone

If you’re like me, you open Logic Pro X to write and quickly end up tone chasing (instead of creating). One amp sim sounds too thin, another too dull, stereo wideners get phasey, you start to add too many plugins and your CPU hates you. Ultimately, you become uninspired and put the guitar down for the day.

This was happening to me far too often. I wanted the “pro” solution of blending two amplifiers, having the flexibility to have dual-mono, full stereo, or even a wet-dry-wet rig all in the box.

This walkthrough is going to show you the exact signal flow I’ve created to accomplish this. It mimics a real life stereo rig, gives you the ability to re-amp down the road if you’re recording, and allows you to add effects both pre and post your amp setup to take the rig even further than you could with an analog stereo setup.

I also created a preset you can download that I’ve made with stock Logic plugins that does all the complex routing for you, you can download it below and completely make it your own. Change out the stock plugins with your favorites, add things for your own personal flair. I still recommend reading through the rest of this post because it will help you understand how it all works and how to best utilize the preset.

How Does a Stereo Rig Actually Work?

Before we build this out in Logic, let’s define the five parts of a real‑world stereo rig so we can mirror it in the DAW. Understanding what that looks like helps serve as our roadmap for how to build this signal flow in Logic:

1. Your raw mono guitar signal
2. Something to split it into designated Left and Right signals
3. Left Amp
4. Right Amp
5. The finished blended tone

The Setup

Here’s how to build each piece in Logic and make it work as one rig.

Start with a dedicated DI track. Keep it for re‑amping, precise edits, and ‘pre‑amp’ pedal plugins that should hit both amps.

There is one catch to doing it this way however, because naturally we would hear our DI signal, which we actually don’t want to hear once we’ve got our full stereo patch going. Here’s what we need to do:

1. Create a new Audio Track and name it “DI”
2. Set the Input to your guitar signal from your interface
3. Set the Output to “No Output”
4. Create a Send/Bus/Aux. Add a Send toBus 1 (or any empty Bus number of your choosing), 
5. Set the Bus to Pre Fader by clicking on the new blue label that says “Bus 1” or possibly “B 1” depending on your screen, and select “Pre Fader” from the dropdown list. 
• Because the DI has “No Output” and the Send is set to “Pre Fader” you’ll never hear the raw DI.
6. Set the Bus level to 0dB
7. Add the Aux track to your Workspace by opening the Mixer (X). Logic created Aux 1 with Bus 1 as its input, right click on Aux 1 and select “Create Track” to add it to your main workspace.
8. Set the Input to Left channel only of Bus 1 by clicking and holding the two overlapping circles next to the label and selecting “Left”
9. Rename this track “Left Amp”
10. Hard Pan this track all the way left
11. Duplicate (right click > New Track with Duplicate Settings) the Left Amp track and rename it “Right Amp”, hard pan it right, and set the input to Right the same way you set it on the previous track.
12. Create a Summing Track Stack by highlighting these 3 tracks (DI, Left Amp, and Right Amp), right click, Create Track Stack, Summing, Create.
13. Name the new track “Stereo Guitar”

At this point, you need to decide on two amp sim’s to use together, it could be two instances of the same plugin with slightly different tones, like using two instances of Logic’s built-in Amp Designer plugin, or it could be completely different amp sim’s from third party developers such as Neural DSP, IK Multimedia, etc. (for a list of some of my favorites check out this post here).

Load one amp sim plugin on the Left Amp track and load the other on the Right Amp track.

Now you need to Record Arm (the red R) and Input Monitor (the orange I) on the DI track so when you play you can hear it, and when you record, it captures your performance. Your takes will record straight to the single DI track, but with this setup you’ll always hear the two amps, and never the DI.

Adding Effects/Mixing

Now that you’ve got your blended amps playable, you can do some light mixing, or add effects just like you might in real life. Here are some options on what you’re capable of doing with this stereo setup:

1. Pre-Amplifier or pedalboard style Effects
• Put mono effects on the DI track (overdrive, wah, filter, etc.). They’ll hit both amps equally. Likewise, you can insert stereo effects if you change the input of the DI track to stereo and the effects will give a true stereo image (think ping pong delays or stereo tremolo).
2. Individual Amp Tweaks
• On the Left Amp or Right Amp, you can add things like EQ after the amp sim plugin to shape each side. It can be helpful to mute the opposite side when dialing in.
3. Shared Post-Amplifier Effects
• Put glue compressors, stereo reverbs, delays or wideners on the Stereo Guitar track to process both amps with one plugin and save CPU.

Conclusion

There you have it, a true stereo multi-amp blend plugin based guitar rig in Logic Pro X. If you want to jump right in and not have to create everything manually, I’ve taken the time to create and export this Summing Stack as a patch for absolutely free that you can load right into your Logic Pro (or Mainstage) session that gives you this exact routing setup instantly. And it’s fully editable. Load in your own amp sims (like Neural DSP, ToneX, Helix Native, NAM, etc.), your own plugins, and effects without having to fuss with all the complex routing. Head here to download it!

Also, if you have any issues that you need to troubleshoot - I’ve got you covered there too. I created a free guide called “The Pro-Level Laptop Guitar Rig Guide” that walks you through not only how to set up a simple and reliable rig, but also some common issues that can pop up and how to fix them. Check that guide out here.