The IK Multimedia AXE I/O Solo is the best interface for guitar, and it is not close: a continuously variable Z-Tone input impedance genuinely changes how your pickups load, switchable PURE and JFET input stages give you a clean and a colored option on the same socket, and a dedicated amp output lets you reamp through a real amp with no extra hardware.
Every other roundup on this site ranks interfaces on published microphone gain, because that is what decides whether your microphone works. This page deliberately does not. A guitar goes into the instrument input, and what matters there is input impedance, how the input stage behaves when you drive it, round-trip latency for amp simulation, and whether you can get the signal back out to a real amp.
Why input impedance is the specification nobody mentions
A passive guitar pickup is an inductor, and what it sounds like depends on what it is loaded with. Plug into a low impedance and you lose high frequencies and the resonant peak flattens — the guitar sounds dull and the pick attack softens. A conventional Hi-Z instrument input fixes that load at one value chosen by the designer, and you take what you are given.
The AXE I/O Solo makes that load continuously variable, which is why it is top of this page. It is the only interface here where you can hear your pickup's resonant peak move.
The Audient iD14 MKII is worth calling out as the runner-up on character rather than features: its instrument input is a discrete JFET stage that sounds deliberately good when you drive it into clipping, which is a different design intent from a clean Hi-Z buffer.
The six interfaces, ranked for guitar
IK Multimedia AXE I/O Solo
Top pickIK Multimedia · Guitar, by a clear margin
Buy it if guitar is the main source and you care about how your pickups load. For voice-led work the money is better spent on an interface that publishes its gain figure.
Why it is here
- Variable input impedance genuinely changes how a pickup loads, which no general-purpose interface offers at any price near this
- A dedicated amp output means you can reamp through a real amp with no extra hardware
- PURE and JFET input stages give you a clean and a colored option on the same socket
What it costs you
- IK does not publish a maximum mic-gain figure, so it is not a box to plan a vocal chain around
- One microphone input and one instrument input — no room to grow
- You are paying for guitar features a voice recordist will never touch
Focusrite Scarlett 2i2 (4th Gen)
Focusrite · The most gain per dollar in a two-input box
The default answer for someone buying an SM7B or PodMic: it supplies enough clean gain that you never need a booster, which makes it the cheaper total purchase even when it is not the cheaper box. Look elsewhere only if you need MIDI or four outputs.
Why it is here
- 69 dB is the most gain of any interface at this price, and enough for an SM7B with headroom to spare
- 120 dB dynamic range means the converters are not the weak link
- Two inputs, so a second person does not mean a second purchase
What it costs you
- Air mode is a fixed voicing, not an EQ you can dial
- Plastic-and-metal build feels less solid than the SSL or Audient competition
- No MIDI, which matters if you also play keys
Universal Audio Volt 2
Universal Audio · A hardware color option on the way in
Buy it if you want character on the way in and your mic is a condenser or a hot dynamic. With a low-output broadcast dynamic, 55 dB means a booster, and that changes the price comparison entirely.
Why it is here
- Vintage mode is a real analog-style color, not a plug-in you could add later
- Two combo inputs and a clean, legible front panel
- The UA software bundle is worth actual money
What it costs you
- 55 dB is the lowest gain ceiling in this group and the least SM7B-friendly
- 112 dB dynamic range trails the Focusrite and MOTU converters
- Vintage mode is a commitment printed into the recording
MOTU M4
MOTU · Four channels, MIDI and the best converters here
The pick if you want MOTU's conversion plus MIDI and a couple of extra line inputs. If you only ever record one or two microphones and do not need MIDI, the M2 does the same job for less.
Why it is here
- 60 dB of published gain and `-129 dBu` EIN is a genuinely quiet channel, and unlike the M2 the figure is published
- MIDI in and out on a box this size saves a separate interface if you play keys
- Full-color LCD metering for all four channels, which is more useful daily than any software mixer
What it costs you
- 60 dB is enough for an SM7B but without much headroom to spare
- Two of the four inputs are line-only, so it is not a four-microphone box
- No onboard voicing or DSP at all
Audient iD14 MKII
Audient · The quietest two-channel preamp pair here
The best-sounding two-channel box in this price band, and the right buy if your microphones are condensers or hot dynamics. With a low-output broadcast dynamic the gain ceiling still forces a booster.
Why it is here
- Two of the same Class-A console preamps as the iD4, at `-129 dB(A)` EIN
- ADAT input means it grows to ten inputs without replacing the box
- JFET instrument input that takes being driven hard
What it costs you
- 58 dB is marginal for an SM7B, exactly as on the iD4
- No MIDI, which at this price is a real omission
- ADAT expansion needs a separate preamp unit you do not own yet
Focusrite Scarlett Solo (4th Gen)
Focusrite · One microphone, one guitar, nothing else
Fine with a hot mic like an MV7+, a BP40 or an SM58. Do not pair it with an SM7B unless you are also buying a booster, and at that point the 2i2 is cheaper overall.
Why it is here
- Same converter generation as the 2i2 for less money
- A dedicated instrument input means mic and guitar at once
- Small enough to live permanently on a crowded desk
What it costs you
- One mic input is a hard ceiling — a guest means a new interface
- Historically the interface people pair with an SM7B and then wonder why it hisses
- No MIDI
Latency, honestly
If you play through amp simulation you are listening to the round trip — in, through the software, and back out. Below roughly 10 ms most players stop noticing; past 20 ms it feels like playing through a delay and you will fight it.
That figure is set mostly by your buffer size and your drivers rather than by which of these boxes you buy, which is why we have not ranked on it. On Windows, driver quality is the dominant factor and the best interfaces for PC page covers it. If you would rather avoid the round trip entirely, every interface here offers direct hardware monitoring — you hear the dry signal with no latency at all, and the amp simulation only in the recording.
What we did not pick, and why
- Amp-modeling floor units used as interfaces. Several are excellent and they are a different purchase — you are buying the modeling and getting an interface attached, which is the reverse of this page's question.
- Interfaces with no dedicated instrument input. A microphone input is the wrong impedance for a passive pickup and will sound thin and quiet however you set the gain.
- Rackmount interfaces. More I/O than a guitarist needs and a form factor that assumes a rack.
- Anything that publishes no instrument-input specification at all. If a manufacturer will not say what the input does, there is nothing to evaluate.
Pair it with
- Monitoring you can trust. Best studio monitors under $500, or headphones if the room is untreated.
- A microphone, if you also want to record the amp. Best XLR microphones covers the general-purpose picks.
- A cable you can trust. Best XLR cables for the microphone side.
How to choose
- If guitar is the main source, take the AXE I/O Solo. The variable impedance and the amp output are features nothing else here offers at any price near it.
- **If you record guitar *and* voice about equally, take the Scarlett 2i2** — 69 dB of mic gain plus two instrument inputs is the better all-rounder.
- If you want character on the way in, take the Volt 2 for its vintage preamp mode, or the iD14 MKII for its JFET instrument stage.
- If you need MIDI for a controller as well, take the MOTU M4.
- If you only ever plug in one guitar and one microphone, the Scarlett Solo is enough.
