Audio Interface Types Explained
Updated Nov 13, 2026 · By 
Jonah Mercer · Editorial policy
As an Amazon Associate I earn from qualifying purchases. Buying through the Amazon links on this page costs you nothing extra. Full disclosure
Audio interfaces differ mainly by their inputs: how many mic preamps they have, whether they take instruments and line signals, and whether they supply 48V phantom power. They also differ by sample rate, outputs, and how they connect to a computer. Pick the type with enough inputs for what you record at the same time.
USB interfaces link mics to a computer
An audio interface sits between a microphone or instrument and a computer, and turns the signal into audio that recording software can use. It provides the mic preamps, the instrument inputs, and the outputs for headphones and speakers.
Count the inputs you need at once
Count the microphones and instruments you record at the same time, since that count sets the number of inputs you need. A microphone and a guitar need 1 mic preamp and 1 instrument input. Recording 2 microphones at once needs 2 mic preamps, so count before you pick an interface.
Mic, instrument, and line inputs differ
XLR inputs take microphones, and Hi-Z instrument inputs take guitar or bass. Line inputs take keyboards and other gear that sends a line signal. Combo inputs accept XLR, line, and instrument plugs in the same socket.
Phantom power and sample rate matter
Condenser microphones need 48V phantom power from the interface, while dynamic microphones do not. Interfaces list a maximum sample rate, such as 48kHz or 192kHz, and a bit depth, such as 24-bit. Check the microphone's own specs for 48V before you connect it, and switch phantom power on at the interface.
Outputs, monitoring, and computer connection
Look for a headphone output for private listening and balanced outputs for speakers. A USB/Direct switch sends the input straight to the headphones for direct monitoring. Most interfaces connect over USB, some with USB-C, and some draw power from the USB cable with no separate power supply.
What you need
Focusrite Scarlett Solo 3rd Gen USB-C Audio
A USB-C interface with 1 XLR mic preamp, 1 Hi-Z instrument input, 24-bit/192kHz recording, a 56dB gain range, Air mode, and a 3-year warranty.
- 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 2 mic preamps, 2-in/2-out, 24-bit/192kHz recording, hardware monitoring, MIDI in and out, and USB bus power.
- 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 2 combo XLR, line, and instrument inputs, 48V phantom power, 48kHz recording, a 1/4-inch headphone output, and a USB/Direct monitoring switch.
- 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 1 XLR mic preamp, 1 Hi-Z instrument input, 24-bit/192kHz recording, a 120dB dynamic range, Air modes, and a 3-year warranty.
- 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
Do I need phantom power for my microphone?
Condenser microphones need 48V phantom power to work, and dynamic microphones do not. Check the microphone's own specs for 48V, and switch phantom power on at the interface, not on the microphone.
How many inputs do I need on an interface?
Count the microphones and instruments you record at the same time. A microphone and a guitar need 1 mic preamp and 1 instrument input, while 2 microphones need 2 mic preamps.
What is the difference between 48kHz and 192kHz?
They are maximum sample rates an interface lists for recording. Both rates appear on interfaces here, so pick by inputs, outputs, and connections rather than by the sample rate alone.
Ranked audio interfaces lists
More how-to guides
Product details come from each Amazon listing and can change. Check the listing before you buy.