So you're ready to jump into the world of amp modeling and you genuinely don't know where to start. I get it. There are a lot of options out there and most of them are great at what they do, which somehow makes the decision harder instead of easier. But something new is here. REACTOR from Positive Grid, the same folks who brought you the Spark series amps that have quietly made their way into bedrooms, studios, and tour buses all over the place. Now they've stepped into the combo amp game with something a little different, something built to push the traditional amp forward instead of just recreating it.
But which one should you choose? The 50W? The 100W? Is REACTOR even the right call for how you play? Let's dig in.
Start With Where You Actually Play
Before you compare anything, be honest about your rooms. Not the rooms you imagine playing someday, the ones you're standing in this month. Most of the buying advice out there gets this backwards and pushes you toward the biggest thing you can afford, which is how people end up with an amp they can never open up. I wrote more about this thinking in our guide on choosing the right guitar amp for where you are as a player, and it holds up here too.
If your world is your practice room, a rehearsal space, and the occasional bar gig where the sound guy is going to mic you anyway, you're a 50W player. If you're regularly on bigger stages, playing rooms where you need real projection and a whole lot of headroom before things start to compress, that's where the 100W earns its keep.
REACTOR 50 vs REACTOR 100
Here's the short version. REACTOR 50 is about feel and immediacy. It gets where you want it to go quickly, and it responds to your hands in a way that feels close and connected. REACTOR 100 is about headroom, punch, and projection. It's got a custom 12" speaker with a premium magnet behind it, and it holds together cleanly when you push it into a big room.
That's really the whole decision. It isn't about one being the serious version and the other being the starter. They're both the same amp underneath with the same brain, the same creative tools, and the same voice. One of them just has more room to shove air around when the room demands it.
Both of Them Work Everywhere
This is the part that usually flips people's thinking, so I want to spend a second on it. Most amps thin out the second you turn them down. You find the tone you love at rehearsal volume, then you go home, drop it to a level your neighbors can live with, and it falls apart into something small and brittle.
REACTOR has selectable wattage, so you can dial the output down to a whisper or open it all the way up, and the tone stays full and present either way. A custom 12" speaker sitting in a wood cabinet gives you the warmth you'd expect at stage volume even when you're playing at midnight in a bedroom. That means the 100W is still completely usable in a small apartment, and the 50W is still perfectly at home on a stage. You're not choosing which rooms you get to play in. You're choosing how much ceiling you want when the big room shows up.
Why a Combo Instead of a Rack or a Floor Unit
A lot of the modeling world assumes you already have the rest of the rig. You buy the brain, then you buy the cab, or you plan on running into the PA, and there's a whole chain of gear standing between you and hearing the thing you just made. That's a totally reasonable way to work if it's how you already work.
But if you want to plug in and immediately hear what you built, a combo makes a lot more sense. With REACTOR you create your tones right in the app, swap gear around, drag things into different positions in the signal chain, and hear the change happen as you make it. No rendering, no reload, no guessing.
And if you're stuck, you can hand REACTOR a starting point instead of a blank page. Describe a sound in your own words, snap a photo of anything that suggests a vibe to you, or feed it a recording, and it will build a complete tone from that in seconds. From there it's yours to take apart and rebuild. Plenty of players who know exactly what a bias point does still start this way, because it's just faster than building from zero. If you want to see how quick that first tone really is, check out our guide on Text-to-Tone.
You can also go past matching existing gear entirely and build amps that don't exist, name them, and share them on Positive Grid's ToneCloud so other players can pull them down and mess with them.
So, Which One Do I Get?
Here's the quick version if you skipped down here, which I absolutely would have done too.
- Choose REACTOR 50 if: you play mostly at home, in a studio, at rehearsal, or in smaller venues, and you want an amp that feels immediate and responsive under your hands.
- Choose REACTOR 100 if: you regularly play larger stages and outdoor shows, and you want the extra headroom, punch, and projection for rooms that ask for it.
- Either one works in every space. Selectable wattage means you keep full, present tone whether you're at bedroom volume or wide open.
- Both share the same tone engine. Same Creator Hub, same app, same amps and effects, same ToneCloud access. The wattage doesn't change what you can create.
- You don't need a cab or a PA to hear it. It's a complete combo amp, so you build a tone and hear it immediately.
- Still deciding? Read Introducing REACTOR for the full story on what the amp does and why we built it.
Whichever one you land on, you're getting the same thing at the core, which is an amp that builds tone the way you imagine it instead of making you work backwards from someone else's idea. Go find yours at the REACTOR page and pick the wattage that matches your rooms.