Audio Interface vs Amp Explained
Updated Nov 13, 2026 · By 
Jonah Mercer · Editorial policy
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An audio interface records a guitar or microphone into the computer, while an amp drives a speaker so the guitar is heard live. The interface has mic preamps, instrument inputs and a converter; the amp has a power stage and a speaker output. Pick the interface to record, and pick the amp to play through a speaker.
What an audio interface does
An audio interface turns a guitar or microphone signal into digital audio for the computer, and turns computer audio back out to headphones or monitors. The Scarlett Solo 3rd Gen takes a mic on the XLR preamp and a guitar on the Hi-Z instrument input, with 56dB of gain range and an Air mode on the preamp. The MOTU M2 takes two mics on two preamps, with hardware monitoring and LCD meters for the levels. The interface takes the place of the amp at the recording stage: the guitar plugs in direct, and the amp sound comes from software in the computer.
What an amp does
An amp takes a guitar signal and drives a speaker, so the guitar is heard live without a computer in the chain. It has a preamp stage for the guitar tone, a power stage for the speaker, and controls for volume and tone on the front. Its place is at the playing end: guitar in, speaker out, with the sound shaped by the amp itself.
Inputs, outputs and monitoring compared
Count the inputs. The Scarlett Solo 3rd Gen and 4th Gen each have an XLR mic preamp and a Hi-Z instrument input, while the MOTU M2 has two preamps and the M-Track Duo has two combo XLR, line and instrument inputs. For listening, the Solo 3rd Gen has low-noise balanced outputs and a headphone jack for private listening, the MOTU M2 has an ESS-driven headphone output with volume, and the M-Track Duo has a 1/4-inch headphone output with a USB/Direct switch for zero latency monitoring. An amp gives a guitar input and a speaker output only, with no mic input and no connection to the computer.
Which device fits the job
Pick an interface when the job is recording: the Solo 3rd Gen and 4th Gen take a mic and a guitar with 24-bit/192kHz converters, the MOTU M2 takes two mics with hardware monitoring, and the M-Track Duo takes two combo inputs with 48V phantom power at 48 kHz. Pick an amp when the job is playing live through a speaker with no computer involved. The Solo 4th Gen adds a 120dB dynamic range and Air modes for the recording side, while the M-Track Duo includes Ableton Live Lite and MPC Beats software for the session.
What you need
Focusrite Scarlett Solo 3rd Gen USB-C Audio
A USB-C interface with an XLR mic preamp, a Hi-Z instrument input, 24-bit/192kHz converters, a 56dB gain range and an Air mode.
- Inputs: 2
- Mic preamps: 1
- Max sample rate: 192 kHz
- Bit depth: 24-bit
- Software named in listing: Pro Tools Intro
- 3-year warranty stated
MOTU M2 USB-C Audio Interface
A USB-C interface with two preamps, 2-in/2-out recording at 24-bit/192kHz, hardware monitoring, LCD meters and MIDI in and out.
- Inputs: 2
- Mic preamps: 2, the most here
- Outputs: 2
- Max sample rate: 192 kHz
- Bit depth: 24-bit
- 2-year warranty stated
M-AUDIO M-Track Duo USB Audio Interface Dual
A USB interface with two combo XLR, line and instrument inputs, 48V phantom power, 48 kHz audio and a 1/4-inch headphone output.
- Inputs: 2
- Max sample rate: 48 kHz
- 48V phantom power
- Software named in listing: Ableton Live Lite
- 0.7 lb, the lightest here
Focusrite Scarlett Solo 4th Gen USB-C Audio
A USB-C interface with an XLR mic preamp, a Hi-Z instrument input, 24-bit/192kHz converters, a 120dB dynamic range and Air modes.
- Inputs: 2
- Mic preamps: 1
- Max sample rate: 192 kHz
- Bit depth: 24-bit
- Software named in listing: Pro Tools Intro
These come from our ranked list Best Audio Interface, which compares them spec by spec.
Frequently asked questions
Can I record a guitar without an amp?
Yes. Plug the guitar into the Hi-Z instrument input of an interface such as the Scarlett Solo, and the interface sends the signal to the computer. The amp sound comes from software in the computer, not from a speaker.
Does an amp plug into an audio interface?
To record an amp, the guitar goes into the interface direct, or the amp line output goes into a line input on the M-Track Duo.
Which interface here takes a guitar and a mic together?
The Scarlett Solo 3rd Gen and 4th Gen each take a mic on the XLR preamp and a guitar on the Hi-Z instrument input. The MOTU M2 and the M-Track Duo also take two inputs at the same time.
Ranked audio interfaces lists
More how-to guides
Product details come from each Amazon listing and can change. Check the listing before you buy.