Stratus vs Positive Grid Spark 2: AI Pedal vs AI Practice Amp

Updated September 18, 2026. Written by Chaos Audio, maker of Stratus. Product specifications and comparison sources are linked below.

If you already have an amp or monitoring setup, Stratus can expand the sounds you make at home and take the same installed presets to rehearsal. It combines NAM captures, looping, and effects created in FX Builder 2.0 in one pedal. Spark 2 includes the speakers and practice tools as well. Start by deciding whether you need a complete practice amp or new sounds for the equipment you already use.

Three NAM models, one Stratus preset. With the latest Chaos Audio app and Stratus firmware 1.0.100, Stratus runs up to three NAM A2-Lite models simultaneously in a single preset/chain, using your own uploads or TONE3000 captures. Each NAM block now uses roughly half the CPU it used before this update; other effects still share the pedal’s processing budget.

As of September 17, 2026, Stratus is the only factory-built compact pedal under US$300 we’re aware of that natively runs three NAM A2-Lite models simultaneously in one preset/chain. Its price is $299. See the latest Stratus and FX Builder 2.0 update.

The short version

• Stratus: Use captures, looping, and a custom effect with the amp or monitoring setup you already have.
• The alternative: Spark 2 includes speakers, headphone monitoring, and integrated practice tools. Account for the equipment you already own.
• Start with the rig: decide which sound, control, or connection you need before comparing catalog totals.

Side by side

How the AI actually works

Spark AI suggests tones using Positive Grid’s models. FX Builder 2.0 supports custom effect creation as well as a verified-capture workflow for many amp and pedal requests.

Spark AI in the Spark app turns a description into tone options built from Positive Grid’s amp and effect library. You can audition and select the result. This is a preset-finding workflow; it does not establish that every request will match what a player wanted.

For a particular sound, describe an effect in FX Builder 2.0—for example, a delay with darker repeats and gentle movement. Audition the result, ask for a change, then install it in your Stratus chain. Pedal captures can feed an amp capture, with other effects sharing the available processing power. Once installed, your sounds run locally and can be recalled without a phone or internet connection. Hear FX Builder 2.0 examples and explore the workflow. The examples on that page are software-rendered demonstrations.

FX Builder 2.0 is now on mobile. Build effects directly in the Chaos Audio app for iOS and Android, then use them in your Stratus chain alongside NAM captures. These current app screenshots show the builder and a finished effect.

The useful difference is what you can refine. With Stratus, shape a custom effect’s behavior and install it beside captures. With Spark AI, explore tones using the amp’s available models. Audition the suggestions and refine or try another result as needed.

Amp tones

Spark 2's amps are Positive Grid's own HD models — all 33 remastered for the new DSP engine, covering electric, acoustic, and bass — plus a ToneCloud community with over 100,000 shared tones. That library, refined across millions of Spark players, is a real strength.

Stratus plays native NAM A2-Lite captures, with up to three NAM blocks in one preset and other effects sharing the CPU budget. These captures represent particular source setups. Spark’s models were not part of the cited NAM format study, and that study is not a head-to-head test of the two complete products.

At home

Spark 2 combines speakers, headphone monitoring, Smart Jam, Auto Chords, Bluetooth playback, and looping. These integrated tools are relevant if you are building a practice setup from scratch or want them in one amp.

With an amp, powered monitor, or interface already in place, Stratus can be a sound-building tool at home too. Prepare a capture/effect chain, loop an idea, and take the same installed preset to rehearsal. Headphone monitoring requires suitable external equipment.

On the board and on stage

Stratus fits on a pedalboard and recalls 14 presets from its footswitches, with up to 128 over USB-MIDI. Use a compatible 9V center-negative supply meeting the current requirement, or supported USB-C power. Conventional MIDI controllers require a USB host.

Spark 2 also has uses beyond the living room. Its line outputs, optional battery, and optional Control X footswitch may suit a rehearsal, jam, or portable setup. Include those accessories when comparing the configuration you actually need.

Cost of ownership

A new practice setup needs amplification and monitoring as well as effects. Spark 2 includes speakers; Stratus requires suitable external equipment. Compare the cost of the complete configuration, including any optional Spark battery or controller. Stratus is US$299 with 19 free effects covering all effect categories, 30 free AI builds every month in FX Builder 2.0, and access to all 600,000+ amp and pedal NAM captures on TONE3000. See the product page for configuration, regional pricing, and shipping estimates.

Openness

Stratus supports the entire TONE3000 NAM catalog, free community presets, and FX Builder 2.0 source access. Spark uses Positive Grid’s models and ToneCloud presets. These are separate formats; source availability is also separate from USB recording or packaged desktop-plugin support.

Which should you buy?

Choose Stratus when you have a way to hear the pedal and want to build a personal capture/effect chain for home or rehearsal. A custom effect can be familiar and useful, such as a delay that stays clear under your playing.

Choose Spark 2 when the missing pieces are speakers, headphone monitoring, and integrated practice tools. Include the total setup cost if you are starting from nothing.

Sources

• Positive Grid — Spark 2 product page (price, features, Spark AI, specs, dimensions)
• Positive Grid — Spark 2 technical specifications (looper length, USB interface, power)
• TONE3000 — NAM Architecture 2 (A2) (test methodology and results; code and data are open source)
• Chaos Audio — Stratus product page (Stratus specs and pricing)
• Chaos Audio — three NAM blocks, firmware 1.0.100, and FX Builder 2.0 on mobile

Explore Stratus, its included effects, and current availability.