Liner Notes
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An audio interface is a peripheral that helps your computer read an audio signal directly from your guitar. Simply connect your guitar to the device (typically via a regular 1/4" guitar cable) and the device to your computer (typically over USB) to capture the analog signal generated by your electric guitar with much higher fidelity than a conventional microphone.

QUICK START: Here's the TL;DR version:
  1. Install and configure your device per manufacturer instructions.
  2. Enable "Show Advanced Options" under FATpick's General Settings.
  3. Go to FATpick's Audio Settings menu and select your audio interface from the "Input Device" drop-down.
  4. Choose the "Port" and "Channel" appropriate to your configuration.
For example, the Focusrite Scarlett Solo presents to your computer as a single, stereo input, with the XLR (microphone) signal on the left channel and the TS/TRS (instrument/line) signal on the right. So when you're connected to the guitar jack at the center of the Solo's front panel, choose "Scarlett Solo USB" (or similar) device, "Port 0" (first and only input), and "Channel 1" (right channel). If you'd like FATpick to list to the Solo's microphone input instead, select "Channel 0" (left channel).

The two inputs to the Scarlett Solo are always mapped to a single stereo output (mic on the left, guitar on the right). But other audio interfaces - including any of the larger devices in the Focusrite Scarlett product line - may support other configurations, such as mapping each input to a distinct single-channel (mono) output, or to independent stereo outputs (on channels 1/2, 3/4, etc.), or even complex hybrid combinations of mono-to-mono, mono-to-stereo, stereo-to-mono and stereo-to-stereo, all at the same time. In these cases it may not be as easy to identify which input or channel your instrument is connected to.

You can use the meter below the volume slider to check if FATpick can hear your instrument in the current configuration. The meter should fill up when you play a note on your guitar. It if doesn't, experiment other port and channel combinations to identify the audio source you're connected to.

See below for more detailed instructions and additional help.

An audio interface gives your computer access to same raw, electronic signal you might otherwise feed to an amplifier - without the noise and side-effects introduced by converting that electric signal to sound (via an amplifier) and back (via a microphone). For this reason, these devices are a staple of the modern home studio: the go-to method for capturing a live guitar performance with a computer, whether for digital recording or for further processing in a digital audio workstation (DAW) like Ableton, Garage Band or Avid Pro. (Or for use by other audio processing software, including FATpick.)

Focusrite Scarlett Solo (3rd Generation)
Focusrite Scarlett Solo (3rd Gen)
The smallest and most popular member of Focusrite's iconic Scarlett device line, this compact, 2-in / 2-out audio interface connects to your computer via USB to capture up to 24 bit / 192 kHz audio from an XLR microphone (left) or 1/4" (6.35mm) TS instrument cable (center), or both at once.

The Scarlett Solo - a compact, 2-input USB audio interface manufactured by Focusrite - is one such device. It is simple but effective - and relatively inexpensive (roughly $150 MSRP) - making it a popular - possibly the most popular - choice for home recording studios for everyone from podcasters to pro/am musicians.

Anecdotally the Solo is also a popular way for FATpick users to connect their guitars to their computer. A large number of FATpick users have reached out to us with questions or feedback about the Solo audio interface, so we've created this post to address some of the most common questions.


While FATpick works well with a traditional (sound-waves-over-air) microphone or a direct guitar-to-computer cable (via AUX or USB, but preferably USB) a dedicated audio interface like the Focusrite Solo offers a number of clear advantages. The sound quality is better (when the input gain on the device is properly adjusted). Application performance is improved by offloading some of the analog-to-digital signal processing to external hardware. Ambient noise and audio "hum" is eliminated, as is interference from the backing audio generated by the FATpick application itself. (No headphones needed.) Latency is reduced by eliminating some or all of the analog-to-sound, sound-to-analog and analog-to-digital conversions that are otherwise present in the processing chain. And most audio interfaces offer more robust options for monitoring and other kinds of audio playback.

You can have a great FATpick experience using nothing more than the built-in mic on your laptop; in fact most users use FATpick in exactly that way. But if you have the opportunity, you should give a dedicated audio interface a try. You're likely to find it works even better that way.

The general strategy behind connecting your guitar to FATpick using an external USB audio interface is illustrated in the following schematic:

USB Audio Interface Schematic
To use the Scarlett Solo with FATpick, plug your guitar cable into the 1/4" "guitar jack" input on the front of the device and connect the device to your computer using the USB-C output port on the back. This will allow FATpick (and other applications) to receive a high-fidelity audio input signal from your guitar.

For a typical Scarlett Solo configuration you'll want to go to FATpick's Audio Settings, select "Scarlett Solo USB" as your input device and choose Port 0 / Channel 1. (If you don't see the input port/channel options you may need to enable Show Advanced Options under General Settings.)

(Find more audio configuration schematics here.)

Essentially, connect your electric or electro-acoustic guitar directly to the audio interface (typically via a 1/4" TS "guitar cable"), and the audio interface directly to your computer (typically via USB), configure your FATpick Audio Settings, and you're good to go.

You can also use other configurations to take advantage of an external audio interface. For example, for a purely acoustic guitar you might connect your external mic to the XLR input of the device. Or you could even connect an electric guitar to an amp and use the XLR mic input to pick up that sound via the audio interface device. See this post for more examples of audio configuration options that FATpick supports. But if a direct guitar-to-interface-to-computer signal chain is an option, that's likely to give you the best experience.

Oh, I should note that as your guitar skills improve you might find an audio interface to be a handy device to have around for other reasons too. If you've ever wanted to play around with digital recording of your guitar - whether to "review the tapes" to learn from your performance, to experiment with accompanying yourself across multiple playbacks, or composing songs with full digital audio production - an audio interface is exactly the equipment you need. Most guitarists could probably put one to good use, with or without FATpick integration.

Most of the rest of this post is dedicated to arming you with the context and background knowledge that may help with the basic interface setup and the "configure your Audio Settings" step of that process, but it's often just as simple as described in the "Quick Start" tip at the top.

Since the Focusrite Solo is both very popular and relatively uncomplicated, it's a great way to explain the basics how to use any audio interface with FATpick.

Focusrite Scarlett Solo (3rd Gen): Front and Back Views
Front and back views of the 3rd Generation Scarlett Solo by Focusrite

But I don't want to leave you with the impression that this is the only or necessarily most compelling option. There are many other excellent (and some equally affordable) USB audio interface models available, both from Focusrite and other manufacturers, including PreSonus, M-Audio, Behringer and MOTU, to name just a few. The information provided here should be applicable to these and most other audio interface devices.

How to Connect Your Guitar to FATpick via a USB Audio Interface

1. Install and configure your device per manufacturer instructions.

Setting up an audio interface can sometimes be as easy as plugging it in to your computer or installing a driver from the manufacturer's website. Other times takes a bit more tinkering to get it working. So the first step is to get the interface to work with your computer in general. Don't worry about anything FATpick-specific until you're able to see the audio interface in your operating system's Sound control panel.

Detailed, device-specific, and computer-specific troubleshooting advice is beyond the scope of this guide - there's simply too much to cover here - but if you run into problems there's generally a lot of help available online. Consult your device's user guide, the support section of the manufacturer's website, peer-support forums, or just search the web at large for answers. Whatever problem you've run into, you're probably not the first. You can usually find a solution if you dig deep enough. (Or, failing that, confirmation that what you're trying to do is not supported.)

2. Enable FATpick's Advanced Settings

While multi-line audio interfaces aren't uncommon - and frankly recommended when available - most users connect their instruments to FATick using a simpler interface like their laptop's built-in microphone, an external USB microphone, or a direct guitar-to-computer connection like a Real-Tone cable. (See Audio Input Configuration Examples for broader view of the options that FATpick supports.) For these users, FATpick's default audio configuration - listening to the first channel (channel 0) of the first input (port 0) of the currently selected device - is the only configuration they need, and will often be the only options available in the port/channel drop-down menus.

To simplify the interface, FATpick hides some of the more complex, confusing or obscure configuration options by default. Multi-input and multi-channel audio is (currently) one of those hidden settings. To see the port (input) and channel controls in the Audio Settings you must first go to the General Settings menu and enable "Show Advanced Options". This will reveal new buttons and controls throughout the app, including several sections of the General Settings menu (so you can immediately see that the advanced options are enabled), and the port and channel controls in the Audio Settings menu.

3. Select Your Audio Device

Go to FATpick's Audio Settings menu and select your audio interface from the "Input Device" list. Look for the device or manufacturer name - in whole or in part - to identify the proper option. For example, the Focusrite Scarlett Solo will be usually be listed as "Scarlett Solo USB" or similar.

Once a device is selected, the "Port" and "Channel" controls will automatically update to reflect the number of inputs FATpick discovered on the selected device and the number of channels discovered within each input.

4. Select the Appropriate Input (Port) and Channel

This is where it can get a little tricky, but only a little.

The proper configuration for the Scarlett Solo may not be obvious, but it is straightforward. The two input on the front of the Solo are always mapped to a single, stereo audio signal. The microphone input (if any) is always connected to the left channel and the guitar input (if any) is always connected to the right channel.

In FATpick's Audio Settings, the Focusrite Scarlett Solo will appear a single audio device ("Scarlett Solo USB"), with a single input ("Port 0") containing two channels ("Channel 0" is the left channel, "Channel 1" is the right channel). Hence:

  • If you want FATpick to listen to the microphone input on your Solo interface, select Port 0, Channel 0.

  • If you want FATpick to listen to the guitar input on your Solo interface, select Port 0, Channel 1.

There usually won't be any other options to choose from.

Larger and more robust devices - those with more jacks to connect to or more flexibility in mapping inputs to outputs - may be less straightforward, but the same general principles will apply. Each physical input on the front of the device will map to some channel of some port. You only need to figure out which one.

TIP: You can use the meter below the volume slider on the Audio Settings menu to check if FATpick can hear your instrument in the current configuration. The meter should fill up when you play a note on your guitar. It if doesn't, experiment other port and channel combinations to identify the audio source you're connected to.

MORE HINTS: Most of the time there aren't that many port/channel options to choose from, so if educated guessing isn't working you can always fall back to the "brute-force" approach of testing each port and channel combination until you identify the right one. But these guidelines may help:

  • Each cable you connect to your audio interface carries an audio signal, but not necessarily a simple one. The input signal could be monophonic (a single-channel) but it might also be stereophonic (two-channel) or something even more complex (multi-channel).

  • These input signals may be split, combined or mixed by the interface in various ways to generate an output signal. That output is ultimately fed to your computer and becomes the virtual inputs presented to applications such as FATpick.

  • These input-to-output mappings almost always match one of the following patterns:

    1. MONO-TO-MONO - A monophonic input is mapped (unchanged) to a monophonic output.

    2. STEREO-TO-STEREO - A stereophonic input is mapped (unchanged) to a stereophonic output.

    3. MONO-TO-STEREO - Two monophonic inputs are combined into a single stereophonic output. (This is how the Scarlett Solo operates.)

    4. STEREO-TO-MONO - One stereophonic input is split into two monophonic outputs.

  • Note that in cases 1 and 2 (mono-to-mono, stereo-to-stereo), the number of input signals is unchanged. Hence a cable connected to the second position on the device will still map to the second output (as long as both the first and second inputs are mapped in this way). Cases 3 and 4 however will cause the input and output counts to diverge. In case #3, two inputs are combined into a single output and in case #4 one input is split into two outputs. Keep this in mind when trying to find the output port that corresponds to a given input port. If your second input is configured as described in case 4 (one stereo to two mono), for example, then the third input will map to the fourth output (and so on), since the input in position 2 is mapped to both output 2 and output 3.

  • The ports (input jacks) on an audio interface are typically numbered from left to right. I.e., the first position is identified by the number 1, the second position by the number 2, and so on.

  • Some applications, however - following a technical indexing convention - start this count with the number 0 rather than the number 1. That means the leftmost position is identified as port 0, the next as port 1, and so on. FATpick is one of these applications, so keep this in mind when matching the inputs on your device to the labels that appear in FATpick. The first input on your audio interface will be labeled "Port 0" within FATpick's audio settings.

Focusrite Scarlett is a trade mark or registered trade mark of Focusrite Audio Engineering Limited in England, USA and/or other countries.

Product images courtesy of Focusrite Audio Engineering Plc.

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