A look back at the first 10 years of AmpStamp, and a technical decision that we’ve never talked about.
It’s hard to believe that AmpStamp turned 10 this January. 10 years of coding, 10 years of listening tests and A/B comparisons, 10 years of chasing classic recordings down endless rabbit holes. We wanted to take a moment to mark the occasion and share something we’ve never really talked about publicly. It’s a technical decision that shaped the sound of AmpStamp from day one, and looking back, we probably should have been talking about it from day one.
Convolution, on a Phone, in 2016
When we shipped the first version of AmpStamp (then called Vintage Guitar) on January 19th, 2016. At the time, the standard approach for cabinet emulation on mobile was algorithmic. A chain of filters, some carefully tuned EQ curves, and a hope that it sounded close enough. It’s a reasonable approach—it’s lightweight, it doesn’t tax the CPU, and on headphones most people couldn’t tell the difference anyway. The major iOS amp sims of the day were all going this route. But there was another approach, well-established on desktop by then, used in plugins like Two Notes Torpedo and various IR loaders that pro studios were already running: convolution. Instead of approximating what a speaker cabinet sounded like with filters, you could take a recorded snapshot of an actual cabinet—an impulse response—and mathematically apply that snapshot to a guitar signal in real time. It’s not an approximation. It’s the actual sound, re-applied.
We went with convolution. With Support for iPhone 4. In 2016.
This was, to put it mildly, not the obvious choice. Real-time convolution at audio rates was expensive on mobile hardware of the day, and getting it to run cleanly while also handling the rest of the signal chain—amp model, effects, all of it—took some work. But the difference in sound was undeniable. A real cabinet has resonances and complex behavior that algorithmic models, no matter how carefully tuned, just don’t fully capture. Once you’ve heard your guitar through a convolution-based cab, going back is hard.
To be clear about what we did: we captured real cabinets ourselves and built a custom convolution engine. We weren’t shipping an IR loader for users to drop in their own files—we were using IRs as the foundation of how every cabinet in AmpStamp sounds, baked in so that guitarists could just pick a cabinet and play. Convolution was the engine, not a feature.
The Part We Kept Quiet About
Here’s the thing—we didn’t talk about it. The technique itself wasn’t patentable, convolution and impulse responses had been around for ages, and the concept of using IRs for guitar cabinets was already old news in high-end studios. What we had was an early, performant implementation on mobile, which is a craft advantage, not a legal one.
The thinking at the time was, if we publicly say AmpStamp uses convolution, we’re basically pointing competitors in the right direction. The work to get there on mobile was nontrivial, but once someone knew where to look, the path got a lot shorter. So we let the app speak for itself and figured guitarists with good ears would notice the difference.
That was a mistake. Not the technical decision—the marketing one.
The Lesson
On the App Store, no one hears the difference unless you tell them what to listen for. Guitarists scrolling through amp sim apps aren’t doing blind A/B tests. They’re reading screenshots and bullet points, often listening through phone speakers, making decisions in seconds. The technical decision that made AmpStamp sound more authentic was completely invisible at the point of purchase.
Meanwhile, “convolution-based cabinet modeling using real impulse responses” is exactly the kind of bullet point that gear nerds among us actually read carefully. We had the substance. We just didn’t put it on the label. It would be years before convolution-based cabinet tech became the standard on iOS. The major mobile amp sims didn’t move in that direction until somewhere between four and seven years after we shipped. By the time the field caught up, the differentiation was gone—and we’d never even claimed the ground when it was ours to claim. It’s a lesson we’re carrying forward.
Hear It For Yourself
Which brings us to Free Previews, our newest feature. The idea is simple—we want everyone to be able to hear these tones, regardless of whether they’ve paid for the gear yet. Pull up a preset, hit play, and hear what AmpStamp actually sounds like. The amp, the cabinet, the convolution under the hood, all of it. No subscription, no purchase, just the tone in your ears.
It’s the answer to a question we should have been asking 10 years ago: how do we let people hear what we’ve built? It turns out the best way is to just let them play it.
Looking Forward
AmpStamp is still going strong. The convolution engine we shipped in 2016 is still doing its thing, still helping guitarists land on tones that sound like the records they love. We’ve added a lot since then—new amps, new cabinets, new effects, the recent Cabinet Drive feature, and most recently the EQ200 Dual Parametric Equalizer which has unlocked a whole new realm of heavy metal tone exploration.
And we’re bringing what we learned to SynthStamp, our new app that launched on April 3rd of this year. SynthStamp is built on the same philosophy—technical decisions that most users won’t see at first, but that you’ll hear immediately. Model 5001 is the first ARP 2600 emulation on mobile, with full patch cabling, and Model B500 is, as far as we can tell, a first-ever circuit-bendable take on the Casio SK-1. All models also accept stereo audio input for real-time effects processing, which almost no other synth app does.
This time, we’re telling you up front. We learned that one the hard way.
Thanks for 10 years of AmpStamp. Here’s to the next 10.
