Audio Interface Specs Database: Preamps, Inputs and Sample Rates

Interfaces are compared here by microphone preamp count, not by the total input number on the box. That number is the one that decides what you can actually record, and it is routinely obscured by headline figures that include line inputs and digital channels you cannot use without buying another box.

If you want the short version: two preamps, a connection your computer already has, and a manufacturer whose drivers will still work in three years. Everything below that is detail, and everything above it is capability you should be able to name a use for before you pay for it.

How do you read an interface specification?

Five numbers, in the order they matter for a home studio:

1. Microphone preamps. How many XLR microphones you can record at once with phantom power. This is the decision.
2. Maximum gain in dB. Not listed in this database because manufacturers report it inconsistently, and the single most useful specification if you own or want a low-output dynamic microphone. Check it on the datasheet.
3. Analogue outputs. Two feeds a monitor pair. Four lets you run an outboard hardware loop without giving up your monitors.
4. Headphone outputs. One is fine alone. Two on independent mixes is the feature that matters the moment a second person is in the room.
5. Connection. Whatever your computer has. For under eight channels this is not the bottleneck people believe it is.

Sample rate ceiling is deliberately last on that list and it is the number people shop on first. See the sample rate comparison for why 48 kHz is the right answer for almost every music recording.

Every interface by microphone preamp count

Sorted by the number that decides the purchase. Analogue in and out count physical jacks only, so digital expansion is listed separately and the comparison stays like for like.

Which interfaces have eight microphone preamps?

Eight is the count that makes a drum kit properly recordable, and there are only 2 of them here. This is the one place where channel count genuinely changes what you can do rather than how conveniently you can do it.

• Focusrite Scarlett 18i20 (4th Gen), 1u rack, $700 and up. Eight microphone preamps in one rack space, which is the number that lets you record a drum kit properly.
• Behringer U-Phoria UMC1820, 1u rack, $150 to $300. Eight microphone preamps in a rack unit for roughly what two-channel boxes cost, which is the reason it exists.

The Behringer UMC1820 is worth calling out specifically because it is frequently bought purely as an eight-channel preamp expander for a better interface over ADAT, which is a legitimate and common use that its price makes possible.

Interfaces by price band

Under $150, 10 interfaces

• Arturia MiniFuse 1, 1 preamp, USB-C. The USB pass-through port saves a hub for a dongle or a controller.
• Audient EVO 4, 2 preamps, USB-C. Smartgain genuinely works and removes the hardest task a beginner faces.
• Behringer U-Phoria UMC22, 1 preamp, USB 2.0 (USB-B). It works, it costs about fifty dollars, and the preamp is not a joke.
• Behringer U-Phoria UMC204HD, 2 preamps, USB 2.0 (USB-B). The spec sheet reads like a two hundred dollar box.
• Focusrite Scarlett Solo (4th Gen), 1 preamp, USB-C. Auto Gain removes the single biggest source of ruined first takes.
• IK Multimedia AXE I/O One, 1 preamp, USB-C. The Z-Tone impedance control genuinely changes how a pickup loads, which no software can replicate.
• M-Audio AIR 192|4, 1 preamp, USB-C. The bundle gets someone recording on day one with no second purchase.
• PreSonus AudioBox 96, 2 preamps, USB 2.0 (USB-B). MIDI in and out at a price where nobody else bothers.
• PreSonus Studio 24c, 2 preamps, USB-C. Nothing important is missing at the price.
• Universal Audio Volt 1, 1 preamp, USB-C. The Vintage switch is a real transformer-flavoured circuit, not a plugin.

$150 to $300, 13 interfaces

• Arturia MiniFuse 2, 2 preamps, USB-C. The bundled Analog Lab library is a real reason to choose this over a spec twin.
• Audient iD4 MkII, 1 preamp, USB-C. The preamp is the same circuit family Audient puts in its large consoles.
• Audient EVO 8, 4 preamps, USB-C. Four bus-powered preamps for the price competitors charge for two.
• Behringer U-Phoria UMC1820, 8 preamps, USB 2.0 (USB-B). Eight preamps at a price nothing else touches. Popular as an ADAT preamp expander.
• Focusrite Scarlett 2i2 (4th Gen), 2 preamps, USB-C. Driver support that survives operating system updates, which is worth more than any spec.
• MOTU M2, 2 preamps, USB-C. Published dynamic range figures that beat every other box in this bracket.
• Native Instruments Komplete Audio 6 MK2, 2 preamps, USB 2.0. Two independent headphone outputs on a bus-powered box.
• Roland Rubix24, 2 preamps, USB 2.0. A hardware limiter on the way in, which stops a surprise loud take from clipping.
• Solid State Logic SSL 2 MkII, 2 preamps, USB-C. The 4K switch is the only tone control on any interface in this bracket that people actually use.
• Steinberg UR22C, 2 preamps, USB-C (USB 3.0). The D-PRE preamps punch above the price, and the DSP reverb makes singers perform better.
• Tascam Series 102i, 2 preamps, USB-C. ADAT expansion at a mid-band price, with a built-in mixer that runs without the computer.
• Universal Audio Volt 2, 2 preamps, USB-C. MIDI ports at a price where most competitors leave them out.
• Zoom UAC-232, 2 preamps, USB-C. You cannot ruin a take by setting the gain wrong. That is a real workflow change, not marketing.

$300 to $700, 10 interfaces

• Audient iD14 MkII, 2 preamps, USB-C. ADAT input means eight more preamps later without replacing the interface.
• Audient iD24, 2 preamps, USB-C. Real monitor control on the desk, which is the feature you miss most once you have had it.
• Focusrite Scarlett 4i4 (4th Gen), 2 preamps, USB-C. Four outputs means an outboard hardware loop is possible without giving up your monitors.
• Focusrite Scarlett 8i6 (4th Gen), 2 preamps, USB-C. Two separate headphone mixes without an external distribution amp.
• MOTU M4, 2 preamps, USB-C. Four outputs and MIDI while staying bus powered, which is rare.
• Solid State Logic SSL 12, 4 preamps, USB-C. The 4K circuit across four channels plus real expansion headroom.
• Steinberg UR44C, 4 preamps, USB-C (USB 3.0). Four good preamps and two headphone mixes while still bus powered.
• Universal Audio Volt 276, 2 preamps, USB-C. Analogue compression before conversion, so a loud singer stops clipping the input.
• Universal Audio Volt 476, 4 preamps, USB-C. Four preamps at a price where most boxes give you two.
• Universal Audio Apollo Solo USB Heritage Edition, 2 preamps, USB-C. Realtime UAD plugins on the input, so you monitor through the sound you intend to keep.

$700 and up, 5 interfaces

• Apogee Duet 3, 2 preamps, USB-C. Converter quality that genuinely belongs in the price band above the enclosure.
• Focusrite Scarlett 18i20 (4th Gen), 8 preamps, USB-C. Eight preamps plus ADAT expansion to sixteen without changing the interface.
• Focusrite Clarett+ 2Pre, 2 preamps, USB-C. Preamps with measurably lower noise than the Scarlett range and genuine ADAT expansion.
• RME Babyface Pro FS, 2 preamps, USB 2.0. Drivers that are still supported a decade after purchase, and routing flexibility nothing else matches.
• Universal Audio Apollo Twin X DUO, 2 preamps, Thunderbolt 3. Round-trip latency low enough that monitoring through plugins stops being a compromise.

What the specifications do not tell you

Three things decide how an interface feels to own, and none of them appear on a specification sheet.

Driver longevity. The most valuable property an interface has, and the hardest to verify before purchase. An interface whose driver stops being updated becomes a paperweight at the next operating system release, and that has happened to plenty of otherwise excellent hardware. RME and Focusrite have the strongest track records here, which is most of what their premium buys.

Maximum gain. Reported inconsistently and omitted here for that reason, and it is the specification that decides whether your microphone will work. Check it directly against the gain staging calculator before ordering.

Metering. Two LEDs versus a real level display is the difference between setting gain by looking at your screen and setting it by looking at the box. Sounds trivial, and it is the thing you interact with on every single take.

Where to go next

• Best audio interfaces: the picks, with reasons, at three tiers
• Best budget interfaces: everything under about $200
• How to choose an audio interface: the full decision, in order
• Complete studio builds: what the interface sits inside, priced at three budgets
• Latency buffer calculator: what your buffer setting actually costs you