Play Guitar in Your Browser with Neural Amp Modeler

Neural Amp Modeler is an open-source project for simulating guitar amps with deep learning, and below is a real, live example of it that lets you play your guitar through your browser. If you have an audio interface, you can plug-in and play through various presets of my amp and pedalboard, and there are also various pre-recorded DIs you can listen to. If you came here from one of my playable articles, there will be a special selection of models to let you explore something from the article. Enjoy!

Parent Article

This is the full source post tied to the player above.

Record out of Your Amp's FX Loop with an Interface

Alex Kraieski

Alex Kraieski

December 25, 2025 · 7 min read
A focusrite Scarlett interface with a Marshall DSL5CR in the background.

The effects loop (FX loop) of an amp lets you route your signal out after the preamp stage (but before the power amp stage) through another signal path of pedals before going back into the amp. Usually, you use it for putting pedals after your preamp, but you can also just record straight out of this into your DAW if you have an interface.

And I think this is a perfect of example of how DAWs, plugins, and modelers don't make tube amps obsolete. I think it all compliments each other as long as you think of it as a modular ecosystem (which has been the point of the electric guitar from the beginning).

Without (unexplained) jargon, here's what I am talking about doing: taking the signal from the FX loop and plugging that into a computer with an audio interface (interface is necessary because guitar cables don't plug directly into usb). Once this signal is in the computer, it gets played through a simulated speaker + microphone that we can choose in software like Logic Pro, Garageband, etc.

Pedals in front of a marshall amp. The top row of the pedal board is the FX loop, starting with a programmable EQ pedal.

How I set it up

My signal chain for this is basically guitar -> front-of-amp pedals -> amp -> fx send -> EQ pedal -> modulation pedals -> delay pedal -> interface -> Cabinet in Archetype Gojira X plugin in DAW.

I am using a Marshall DSL5CR combo amp. Some things will may be different with between amps, but the basic idea is that without disconnecting the speaker, (I think this prevents any avenues of harming your amp, but everything in this article is at-your-own-risk) you run the cable from the last pedal in your FX loop straight into your interface. Also, on my Focusrite Scarlett 2i2, I made sure to deselect "Inst" mode since it is no longer an instrument-level signal. My Focusrite (which is basically entry level btw) still has plenty of headroom for this application.

This wasn't "silent" for me, as there was still a "dry" signal going through the speaker, but I was able to run the amp quieter for this than I ideally would for practicing or recording the speaker with a mic.

The back of a Marshall amp show the the FX loop return is unplugged.

In my computer (a Macbook), I use Logic Pro to run amp sims like the Neural DSP line. In this case, we want to use their Archetype Gojira plugin not for its amps, but for the impulse responses (IRs). Each of the 3 amps has a default cabinet matched with it, and you can also choose different microphones.

So when I turn off the amp in the plugin, I get my pedal + Marshall preamp sound through whatever cabinet I select. Pretty neat, I think!

Screenshot of the Archetype Gojira Plugin software showing a virtual amp and cabinet. The amp section is powered off.

Benefits

  • Modularity: now my combo and FX loop pedals can be used with a variety of cabs/mics outside of the built in speaker and mics I own

  • Can blend the mic'd up speaker back in

  • Bring real tube feel into digital workflows'

  • Leverages your familiarity with how your physical pedals and amp interact

  • Try out different cabs without having to physically play the song again and place the mic accurately each time.

    The main downsides are that this isn't a silent process (at least on my amp) and that your sound is going to be missing any impact on the response or tone from the power tube. But I'm not enough of an expert to say that's an "invalid guitar tone." One of the big mistakes people can make is to not use an IR, but that's not what we're doing here.

Examples with each cab in the Neural DSP Archetype Gojira Plugin

Sorry for sloppy playing... I broke a string on this take by pulling back too hard with my Floyd at the end, so I hope we can make it do for now. Here's the same crappy take on each cab in the Gojira plugin:

Cab 1:

Cab 2:

Cab 3:

I think all of those are potentially viable amp + cab combos (with more dialing in depending on what you are going for). It could also work blended with a channel with a dynamic mic on the amp. I think cab 2 might get lost in a mix as I had it dialed in for this.

Say what you want about my playing or tone, but it's not the least original tone anyone's done with the Gojira plugin.

Subjectively, it feels like some "Marshall Roar" is missing (compared to the "in-the-room sound" of the combo). I'm not sure if that is because we aren't getting the EL34 power tubes or if what I'm missing is a characteristic of the speaking in my combo.

A low effort take on the proliferation of DAWs and modeling in the guitar world is that it will kill tube amps (or is already killing them). In reality, tube amps have more value than ever because we can remix them into digital recording/production flows in fun ways. You can try out different IRs with your own preamp sound and make your own IRs too. Even if you love recording directly into your interface (without a mic), it seems like owning a tube amp is an asset that expands your arsenal. Unless you want to sound like everyone else.

If you need an interface, Focusrite's Scarlett series is well-regarded at the "entry-level but not junk" price tier. I use the 2i2 currently, which gives me a couple inputs at my disposal.

Thanks for reading, and always keep experimenting with your sound!

Updates

Update 1

To add a power amp back to this kind of setup, you can use NAM power amp models to approximate what it would be like to have a real power amp section between the preamp and the cabinet

Update 2

Now, you can hear what your playing sounds like with my Marshall's preamp with my site's Neural Amp Modeler integration

You can also check out the full tone pack on TONE3000's community!

This isn't just about my gear and site; it's all a part of an ecosystem backed by open-source technology. Neural Amp Modeler itself is open-source, and this player here is forked from TONE3000's own MIT-licensed fork of NAM for browsers. Their site is also an essential community for sharing tones (here's my profile there).

NAM also runs in DAWs (with the plugin), pedals (like this one at $60ish for something starter-tier I've reviewed), and practice amps. I aim to fit into this universe with "playable articles" where players learn with their own fingers and guitars.

I am not affiliated with TONE3000 (T3K), but I appreciate their contribution to the open-source ecosystem! I want to thank TONE3000 and Steve Atkinson for making this possible.

What you need

  • nothing but a browser to hear demo tracks

  • an audio interface and instrument to play live

  • headphones/speakers

An audio interface lets you plug an instrument cable (and more) into your computer. If you are looking for an entry-level interface to get going playing and recording guitar through your computer, Focusrite's Scarlett series is a common, solid starting point that I've examined here.

Try playable articles

There are a lot of talented people out there demoing and writing about gear online, but their tone isn't yours. And their words about how something feels will never translate exactly to how you will experience it.

I created playable articles here at Tubes & Code to close this gap and put the focus back on your playing. These articles will let you load into this player with sets of NAM models and impulse responses curated to let you explore a topic. For example, you can play with different microphone positions or see what a preamp-only guitar tone sounds and feels like.

Why does open-source matter?

In addition to the practical benefits of the "playable article" experience, I think embedding NAM right here in my website helps demonstrate what an open-source approach brings to the table and why guitarists should care.

There are a lot of proprietary modeling/capture ecosystems out there owned by companies. The engineers at these companies do an impressive job (broadly speaking), but the ecosystems are ultimately designed to protect the company's ability to tell you where you're allowed to take your tone. These boundaries mean that certain types of knowledge about these technologies is restricted to those inside the company.

Imagine a tube amp that's 100% unfixable by amp techs. NAM is the opposite of that. Nothing stops guitarists, developers, and sound engineers from learning more about NAM and building products and content that further grow the ecosystem and collective knowledge.

A2: Now NAM is better than ever

With NAM's A2 architectural update, the team at T3K has delivered a massive step forward and provided convincing evidence that it is the most accurate amp modeling technology out there.

I am proud to integrate A2 into Tubes & Code. It fits perfectly with my goal of bringing guitar tones to life on the web for you to try and learn stuff.

I am hopeful the efficiency of A2 should help you enjoy a better experience here on a wider range of devices. Check out my article breaking down the architectural changes and what it means for guitarists and bassists!