Can You Use the Positive Grid Spark 40 as an Audio Interface for Logic Pro?

Yes. The Positive Grid Spark 40 has a USB port, and when you connect it to a Mac it appears in Logic Pro as an audio input and output device. You record the amp's processed sound, exactly what you hear from the speaker, straight onto a track. For practice recordings, quick demos, and the first year of my YouTube channel, that is how I recorded guitar. For the album I moved on, and I will tell you why.

Here is the setup, the limitations, and when it stops being enough.

Setup in Logic Pro

1. Connect the Spark 40 to the Mac with a USB cable (the port is on the back).
2. In Logic Pro, open Settings > Audio > Devices and set the Spark as the input device. Leave the output on the Mac or your usual interface so you hear Logic's playback while the Spark's speaker gives you the guitar.
3. Create an audio track with the Spark's input. The Spark sends a stereo signal.
4. Record. What you hear from the amp is what lands on the track.

If you don't see the Spark in the list, check the USB cable and that the amp is on. It is class compliant, so there is no driver to install on macOS.

What you are recording

The processed amp sound. Tone, effects, and all. You cannot change the amp afterward in Logic unless you also captured a dry signal. The Spark app has a USB setting that affects what goes down the cable. Check that setting before you track anything you care about.

What works well

• Demos and scratch tracks. Dial the tone on the phone, play, done.
• Practice logging. Record every session and listen back.
• YouTube demos of the amp itself, because the audience hears exactly what the amp does.

Where it falls short for a release

• One input. Guitar or the aux, not a mic and a guitar at once.
• No dry track workflow without extra steps, so re-amping later is awkward.
• Latency and monitoring are fine through the amp's own speaker, but if you want to monitor through Logic with plugins, you are back to an interface anyway.
• Headphone mix for tracking vocals or drums alongside guitar isn't something the Spark is designed for.

None of this matters for a demo. All of it matters when you are tracking an album alone and want one box to handle guitar, bass, and a vocal.

What I moved to

The Headrush Core. It is a floor modeller with a proper USB audio interface built in, a mic input, and a tone I commit to at the pedalboard. The setup post is how to record the Headrush Core into Logic Pro over USB. The Spark 40 is still in the room as a practice amp, and the Spark 2 took over desk duty.

FAQ

Does the Spark 40 work as a USB audio interface?

Yes. Connect it by USB and it appears as an audio device in Logic Pro and other DAWs on macOS without a driver.

Can you record a dry guitar signal from the Spark 40?

It depends on the USB audio setting in the Spark app. By default you get the processed amp sound.

Is the Spark 40 good enough to record an album?

For demos, yes. For a release, a dedicated interface or a modeller with a full interface built in will save you a lot of workarounds.

Bottom line

USB in, pick it in Logic, record the processed sound. Great for demos, limiting for a release. The Spark 40, Spark 2, and the Headrush Core that replaced them for tracking are all on the rig page.