Scarlett 18i16 4th Gen

Powering on your Scarlett

Your Scarlett is now powered on and ready to use.

Easy Start

Easy Start gives you a step-by-step guide to setting up your Scarlett and creates personalised tutorials based on how you plan to use your Scarlett. This online tool also guides you through your Scarlett's registration process and accessing the software bundle.

On both Windows and Mac computers, when you connect your Scarlett to your computer, it first appears as a Mass Storage Device, like a USB drive. Open the drive and double click 'Click Here To Get Started.url'. Click 'Get Started' to open Easy Start in your web browser.

After you've opened Easy Start, follow the step-by-step guide, to install and use your Scarlett.

Windows

After you connect your Scarlett 18i16 to your computer, a device appears in File Explorer called Scarlett 18i16 4th Gen, this allows you to access Easy Start.

To access Easy Start:

1. Open File Explorer.
2. Click on Scarlett 18i16 4th Gen (D:). The letter may be different.
3. Double-click Click Here to Get Started. This redirects you to the Focusrite website, where we recommend you register your device:
4. Click Get Started, and we'll take you through a step-by-step setup guide based on how you want to use your Scarlett.

During Easy Start, you'll install Focusrite Control 2. After you install and open Focusrite Control 2, click 'Update Scarlett 18i16'. Do not disconnect your Scarlett while Focusrite Control 2 updates it. After the Focusrite Control 2 update is complete, the Scarlett no longer appears as a Mass Storage Device on your computer.

Your operating system should change the computer's default audio inputs and outputs to the Scarlett.

To verify this, right-click the speaker icon on the Windows taskbar, and make sure Scarlett is your Sound output.

Mac

After you connect your Scarlett 18i16 to your computer, a Scarlett icon appears on the desktop or, if you use Chrome, you'll see a pop-up:

To access Easy Start:

1. Double-click on the icon to open the Finder window shown below:
2. Double-click Click Here to Get Started. This redirects you to the Focusrite website, where we recommend you register your device:
3. Click Get Started, and we'll take you through a step-by-step setup guide based on how you want to use your Scarlett.

During Easy Start, you'll install Focusrite Control 2. After you install and open Focusrite Control 2, click 'Update Scarlett 18i16'. Do not disconnect your Scarlett while Focusrite Control 2 updates it. After the Focusrite Control 2 update is complete, the Scarlett no longer appears as a Mass Storage Device on your computer.

Your operating system should change the computer's default audio inputs and outputs to the Scarlett.

To verify this, go to System Settings > Sound, and ensure the input and output are set to Scarlett 18i16.

All Users

The second file - 'More Info and FAQs' - is also available during the setup process. This file has some more information about Easy Start, which you may find helpful if you have any issues with the setup.

Once registered, you have immediate access to the following resources:

• Focusrite Control 2 (Mac and Windows versions available) - see note below.
• Multi-language User Guides - also always available from downloads.focusrite.com.
• Licence codes and links for the optional bundled software in your Focusrite account. To find out what bundled software is included with Scarlett 18i16, please visit our website: focusrite.com/scarlett.

What is Focusrite Control 2?

Focusrite Control 2 is the software application you use to control your Scarlett interface.

We occasionally update your Scarlett 18i16's firmware with new features and improvements, to make sure you are getting the most from your Scarlett. Focusrite Control 2 updates your Scarlett 18i16's firmware.

Focusrite Control 2 allows you to control various features of your Scarlett from your computer.

Installing Focusrite Control 2

You can install Focusrite Control 2 on Windows and Mac. To download and install Focusrite Control 2:

1. Go to the Focusrite downloads website: focusrite.com/downloads
2. Find your Scarlett on the Downloads website.
3. Download Focusrite Control 2 for your operating system (Windows or Mac).
4. Open the Downloads folder on your computer and double-click the Focusrite Control 2 installer.
5. Follow the on-screen instructions to install Focusrite Control 2.
6. If it's not already, connect your Scarlett interface to your computer with the USB cable.
7. Open Focusrite Control 2 and it detects your Scarlett automatically.

Manual Registration

If you decide to register your Scarlett at a later date, you can at: customer.focusrite.com/register

In Easy Start mode, the interface functions at up to 48 kHz sample rate; once you install Focusrite Control 2, you can work at sample rates up to 192 kHz.

If you don't install Focusrite Control 2 immediately, you can download it at any time from: downloads.focusrite.com

Manually disabling Easy Start

After you've been through Easy Start, installed and opened Focusrite Control 2, your Scarlett is no longer in Easy Start mode.

If your Scarlett 18i16 is still in Easy Start mode, or you have chosen not to install Focusrite Control 2 to disable Easy Start Mode:

1. Turn off your Scarlett 18i16.
2. Press and hold the 48V button.
3. Keeping the 48V button held, power on your Scarlett 18i16.
4. Wait for the front panel to light up, then release the 48V button.
5. Restart (power off and power on) your Scarlett 18i16.

Your Scarlett powers on with Easy Start disabled.

Front Panel

1. Inputs 1–4 Gain Controls and Gain Halos - The Gain control sets the input level and the Gain Halo shows you the input and preamp gain levels for either the jack or XLR Mic input.
2. Inputs 1–4 Neutrik® Combo XLR and 6.35mm (1/4") jack connectors. Accepts XLR mic-level inputs, or unbalanced mono (TS) and balanced Mono (TRS) 1/4" jack cables at line level. Inputs 1 and 2 can also accept instrument-level.
3. Select button - Press to move the selection to the next preamp. The other buttons change to control the input you select. The currently selected channel's number lights green.
4. 48V button - Press to turn on 48V phantom power at the XLR mic input to power condenser microphones. You can set 48V independently per preamp channel.
5. Air button - Press to turn on AIR mode (see AIR).
6. Inst button - Press to toggle the selected 6.35mm (1/4") input between Line or Instrument level.
7. Auto button - Press to start the Auto Gain feature (see Auto Gain).
8. Safe button - Press to turn on the Clip Safe feature for your input (see Safe).
9. Alt button - press the Alt button to route the signal going to the first monitor output pair (1 and 2) and the second monitor output pair (3 and 4). To use two pairs of monitors and switch between them, see Alt.
10. Main Speaker Output Control and Output Level meter - Controls the level going to Outputs 1 and 2. The meter shows you the level being sent out.
11. Status icons
    • USB LED - Lights green when your computer recognises your Scarlett, and white if it is disconnected from your computer (in standalone mode).
    • Sync Status - Lights green when your Scarlett 18i16 is synchronised with itself or an external digital device. It lights white when it can't lock. For more information, see the Sync Status section.
12. Mute button - silences the signal being sent to your outputs.
13. Headphone level control and output sockets - Connect up to two sets of headphones to the output sockets and control the output with the corresponding level control.

Back Panel

1. Power switch - O is the off position, I is the on position.
2. Kensington Lock - use a lock to secure your Scarlett and deter theft.
3. 5V DC - a USB-C connector to supply power to your Scarlett 18i16. Use the included USB-C power supply.
4. USB - USB-C connector to connect your Scarlett to your computer. You can also bus-power your Scarlett 18i16 if your computer's USB port can supply 3 Amps.
5. S/PDIF Out and In - two coaxial RCA sockets for two-channel S/PDIF digital audio signals in and out. See Sync Status and using your Scarlett with ADAT and S/PDIF for information on how to set up your Scarlett 18i16 with a S/PDIF device.
6. Optical Out and In - two TOSLINK™ connectors for eight channels of digital audio in ADAT format at 44.1/48 kHz and four channels at 88.2/96kHz. See Sync Status and using your Scarlett with ADAT and S/PDIF for information on how to set up your Scarlett 18i16 with an ADAT device.
7. MIDI Out and In - standard 5-pin DIN sockets for external MIDI equipment. The Scarlett 18i16 acts as a MIDI interface, allowing MIDI data to/from your computer.
8. Line Outputs 1–4 - Neutrik® 1/4" jack (TS or TRS) sockets to connect your Scarlett to line-level inputs on devices such as monitor speakers, amplifiers, mixers or external processors. Use 1/4" TRS jack cables for balanced connections where possible.
9. Line Inputs 5–8 - Neutrik® 6.35mm (1/4”) jack sockets. Accepts both unbalanced mono (TS) and balanced Mono (TRS) 1/4" jack cables at line-level.

Your Scarlett 18i16's front panel in depth

This section covers all the features on your Scarlett 18i16's front panel, what they do, how you might use them, and how they work in Focusrite Control 2.

Microphone Inputs

You can control your microphone level using the corresponding input gain control on the front panel. 48V phantom power is also available if you are using a condenser mic, you can enable phantom power using the front panel 48V button.

Setting your Scarlett 18i16's preamp input gain

The preamp input gain controls how much signal you are sending into your computer and recording software.

It's essential to set a good level for the preamp input gain so you get the best quality recording. If the preamp input gain is too low, your signal will be too quiet and when you try to boost its level later you may hear noise in the recording; if the preamp input gain is too high you might 'clip' the input and hear harsh distortion in your recording.

To increase the input gain, turn the gain control clockwise. As you move the gain control, the Gain Halo gradually lights clockwise to show you the gain level. This diagram shows the gain at various levels:

1. No input gain
2. 25% input gain
3. 50% input gain
4. 75% input gain
5. 100% input gain

When you adjust your input gain while you send a signal into your preamp, the ring lights the same way as above but a colour, green, amber or red, shows how much level is going into your computer. Shortly after you stop adjusting the gain the meters revert to input meters (see Input Metering).

1. Gain at 40%, signal good.
2. Gain at 40%, signal pre-clip.
3. Gain at 40%, signal clipping.

Green shows your signal level is good. Amber shows your signal is pre-clip, any higher and you are likely to clip the input. Red shows your signal has clipped, you should reduce the gain.

Software Gain Control – you can also control the preamp gain remotely using Focusrite Control 2.

To adjust the preamp gain in Focusrite Control 2:

1. Click the virtual knob for the channel you'd like to adjust or use the tab key to select the preamp gain control.
2. Move your mouse up and down or use the arrow keys to increase or decrease the gain (in ±1dB increments).

The following images show the preamp gain at minimum, medium and maximum gain.

Input Metering – when you're not moving the input gain control the input metering uses the entire Gain Halo. As the incoming signal gets louder (for example with a higher input gain setting) the Gain Halo lights from green through to amber before the entire Gain Halo flashes red to show you the input has clipped.

This diagram shows the meters at different levels to show the input signal level:

1. No input signal
2. -42 dBFS
3. -36 dBFS
4. -24 dBFS
5. -18 dBFS
6. -12 dBFS
7. -6 dBFS
8. 0 dBFS, clipping - turn down the input gain to avoid distortion and clipping.

Software Metering – in the same way as the input meters on your Scarlett 18i16's front panel, you can see the incoming signal on the meters in Focusrite Control 2 to set the correct preamp gain.

The indicator above the meter shows you the peak level (in -dBFS), the highest level on this track since you started monitoring the input. When you hover over the Peak level meter, you can click to Reset the value.

When you overload the preamp, with too much input signal, or by adding too much gain, the Peak Level Meter lights red. Hover over the Peak Level Meter and click to Reset the value.

Select Button

Many front panel controls on your Scarlett 18i16 are shared across the preamp inputs. The Select button moves the preamp controls to different inputs.

At least one preamp is always selected, to change which preamp(s) the controls are affecting, press the Select button. When you do this, the newly selected preamp's number lights green and the preamp setting lights change to match the new preamp.

When you turn on your Scarlett 18i16 the last selected preamp before you turned it off remains the selected preamp.

Linking Preamps

Linking preamps allows you to control two preamps simultaneously using one set of preamp controls. You can match gain controls for two preamps and enable other preamp controls. This is useful for stereo recording, for example, a microphone pair, stereo synthesiser, or keyboard.

To link preamps:

• Press and hold the Select button for one second.

When you've made the Preamp Link:

• Both preamp numbers light green and the Gain Halos light temporarily to their preamp level.
• The preamp gain level is set to the lowest value of the newly linked pair.
• The preamp settings are inherited from the currently selected preamp, e.g. preamp 1 is selected, therefore Preamp 2 inherits, Air, Safe and Inst settings from Preamp 1.
• Changing any preamp setting changes the state for both preamps.
• Adjusting either gain control changes the gain level for both preamps and is shown on both Gain Halos.
• 48V disables for both preamps.

Unlinking Preamps – to unlink preamps, hold the Select button for one second. When you unlink a pair:

• The first preamp of the previously linked pair becomes selected and lights green.
• Gain levels and preamp settings stay the same, but you can now change them independently.

Linking Preamps in Focusrite Control 2 – to link preamps from Focusrite Control 2, click the link icon at the top of the channel strip.

When you link two preamps, the link icon turns green, one set of preamp controls disappears, and the meters for each channel merge to form a stereo meter.

Unlinking Preamps in Focusrite Control 2 – to unlink preamps from Focusrite Control 2 and control them independently again, click the green link icon at the top of the channel strip.

When you unlink two preamps, the link icon returns to black/white, two sets of preamp controls appear, and the meters split again for each separate channel.

When you unlink preamps:

• The first preamp of the previously linked pair becomes selected and lights green.
• Gain levels and preamp settings stay the same, but you can now change them independently.

48V button (Phantom Power)

48V, also commonly referred to as 'Phantom Power', sends 48 Volts from your interface's XLR connector to devices needing power to work. The most common use is sending power to condenser microphones, but you may also need 48V for inline mic preamps, active dynamic microphones and active DI boxes.

The 48V icon lights green to show it is enabled.

48V phantom power is now being sent to the selected XLR input and to any devices connected to the XLR input.

48V (Phantom Power) Software Control – to enable 48V (Phantom Power) from Focusrite Control 2 click the +48V button for the input you want to enable it on. This is the same as pressing the 48V button on the Scarlett 18i16 hardware.

Inst (Instrument) Button and Line Level Inputs

Inst, or instrument, changes the impedance and input level of the 6.35mm (1/4") jack inputs on your Scarlett so the inputs sound their best for either an instrument or line-level source. We list the input impedance values in the Specifications section. If you don't turn on Inst and connect an electric guitar, the resulting sound can be muddy and quiet compared to with Inst on.

The Inst (Instrument) button only affects the 6.35mm (1/4") line input for the selected channel, either input 1 or input 2. It changes it from an input suitable for line-level devices to an input better suited for instrument-level devices.

To enable, or disable, instrument mode for the 6.35mm (1/4") jack input, select the channel and press the Inst button once. Green shows Inst is enabled, and white shows Inst is disabled. When you enable Inst and connect a jack to your Scarlett, the minimum gain for the input is changed to +7dB.

When Inst is enabled (green) you can connect instrument-level devices to the 1/4" inputs such as, but not limited to:

• Electric or electro-acoustic guitars directly and via effects pedals.
• Electric basses
• Acoustic instruments with pick-ups such as violins, double basses etc.

When Inst is disabled (white) you can connect line-level devices to the 6.35mm (1/4") inputs such as, but not limited to:

• Synthesisers
• Keyboards
• Drum Machines
• External Microphone Preamps

Instrument/Line Software Control – to change inputs 1 or 2 between instrument and line from Focusrite Control 2 click the Inst button once.

Air Modes

Air lets you change your Scarlett's preamp sound with two different modes; Air Presence or Air Presence and Harmonic Drive.

Air Software Control – to enable AIR from Focusrite Control 2 click the Air button. This is the same as pressing the Air button on the Scarlett 18i16 hardware.

When you click Focusrite Control 2's Air button, the last selected Air mode becomes activated. To change the selected Air mode (Presence or Presence and Drive) click the arrow to show the dropdown menu.

Auto Gain

Auto Gain allows you to send a signal into your Scarlett 18i16 (for example singing or playing your instrument) for 10 seconds and let the Scarlett set a good level for your preamps. If you find the levels aren't right, you can adjust the gain controls manually to fine-tune the levels before recording.

To use Auto Gain:

1. Press the Select button to move your preamp controls to the correct preamp.
2. Press the white Auto button on your Scarlett, or the corresponding software button. The Auto icon lights green for ten seconds.
3. Speak or sing into the microphone, or play your instrument during the Auto Gain countdown. Perform as you would while you're recording to make sure Auto Gain sets a good level.

If the Auto Gain was successful, the Gain Halo lights green before the gain value is shown on the Gain Halo for a second. The gain is now set at a good level for your recording.

If Auto Gain fails, the Gain Halo lights red. Please see the section, The Gain Halo turned Red, for more information.

Auto Gain Software Control – to use Auto Gain in Focusrite Control 2:

1. Click the Auto Gain button in Focusrite Control 2.
2. Speak or sing into the microphone, or play your instrument during the Auto Gain countdown. Perform as you would while you're recording to make sure Auto Gain sets a good level. The Auto Gain process starts and the software Gain halo turns into a countdown timer.

Before running Auto Gain again, make sure your input has something connected to it correctly, if you're using a condenser microphone, 48V is on, and you are making sound while Auto Gain runs.

If the Auto Gain was successful, the Gain Halo lights green before the gain value is shown on the Gain Halo for a second. The gain is now set at a good level for your recording.

If the input signal is unsuitable for Auto Gain (for example there's no signal detected), after ten seconds, Auto Gain stops and the Gain Halo lights red for a second. The gain returns to the value you set before starting Auto Gain.

Multichannel Auto Gain

Auto Gain allows you to send a signal into your Scarlett 18i16 (for example singing or playing your instrument) for 10 seconds and let the Scarlett set a good level for your preamps. If you find the levels aren't right, you can adjust the gain controls manually to fine-tune the levels before recording.

Multichannel Auto Gain starts the Auto Gain process for all the preamp channels on your interface. This is particularly useful for quickly setting levels for situations where you are using multiple channels simultaneously, for example:

• Setting levels for yourself if you're playing guitar and singing simultaneously.
• Setting levels for a drummer when you have multiple microphones on the drum kit.
• Setting levels for a band recording 'live' together.

To start the multichannel Auto Gain process:

1. Hold the Auto button for two seconds. The Auto icon fades between off and Green for ten seconds, and the Gain Halos for all channels turn into ten-second countdown timers.
2. Speak or sing into the microphone, or play your instrument during the Auto Gain countdown. Perform as you would while you're recording to make sure Auto Gain sets a good level.

If the Auto Gain was successful, the Gain Halos light green before the gain value is shown on the Gain Halos for a second. The gain is now set at a good level for your recording.

Multichannel Auto Gain in Focusrite Control 2 – you can also run multichannel Auto Gain from within Focusrite Control 2. To do this:

1. Open Focusrite Control 2 and go to the Inputs tab.
2. Click the dropdown arrow to the right of the usual Auto Gain button.
3. Choose Auto Gain All – this starts running Auto Gain for all the channels on your Scarlett 18i16.

Once Auto Gain has finished, Focusrite Control 2 shows the channels that have been set and their new gain levels.

Multichannel Auto Gain failed – multichannel Auto Gain might fail during the process for one, multiple, or all channels. You can either:

• Click Retry and all Auto Gain runs again for all the channels you ran Auto Gain for, even the successful channels.
• Click close and run Auto Gain for any failed channels.
• Click close and manually adjust the gain for any failed channels.

Clip Safe Button

The Safe button applies Clip Safe, which automatically adjusts your preamp gain if you're at risk of clipping.

Clipping happens when your gain is set too high for the sound being recorded and your input overloads the preamp. A clipping symptom is preamp distortion, which is often unpleasant and can ruin a recording. Clip Safe helps you avoid this so if your input gets near to clipping, Clip Safe reduces the preamp gain, so you won't have to re-record your take.

To enable Clip Safe:

1. Press the Select button to move your preamp controls to the correct preamp.
2. Press the Safe button on the interface or the corresponding software button.

When you enable Safe, the Safe icon lights green.

When you have two inputs selected using Preamp Link, Safe is applied to both preamps.

Output Control and Level Meter

The Output control and Output level meter are related to the signals going to Outputs 1 and 2 on the back of your Scarlett 18i16, the outputs you'd most often connect to monitor speakers.

The Output control sets the level at the outputs from nothing (fully anti-clockwise) to full-scale output (fully clockwise).

The Output Level meter around the Output level control is a pre-fade meter (it is not affected by the control's position) showing you the signal level coming from your computer.

Mute Button

The Mute button silences the signal being sent to your outputs. When active, Mute lights green.

By default, Mute affects the Main monitor outputs 1 and 2, but in Focusrite Control 2 you can change this to control your Alt outputs.

Mute Software Control – to enable/disable Mute in Focusrite Control 2 click the Mute button in the Outputs section on the right.

The Mute button works in the same way as the Mute button on the front panel of your Scarlett 18i16. When active, Mute lights green.

Sync Status and using your Scarlett with ADAT and S/PDIF

The Sync Status icon on the front panel lights green when your Scarlett 18i16 is 'locked' to or 'synchronised' with a clock source.

The Sync Status indicator is most useful when you're trying to expand the channel count using your Scarlett 18i16 with other equipment connected to your Scarlett 18i16's digital inputs or outputs; the ADAT or S/PDIF IO.

When you're using the digital inputs your Scarlett 18i16 and the other audio devices need to have their internal clocks synchronised, using clock signals, so their audio is recorded in time.

Depending on what type of digital device you're connecting to your Scarlett 18i16 (ADAT, coaxial S/PDIF, or optical S/PDIF) you need to make sure the digital IO mode is set correctly in Focusrite Control 2.

There are a few principles when you're trying to synchronise multiple digital audio devices:

• The clock signal can be embedded into the audio signal, down the same cables (e.g. S/PDIF, or ADAT).
• Clock signals are always one-way, you can't send and receive clock signals using one ADAT or S/PDIF cable.
• There are Clock Leaders and Clock Followers. Devices 'follow' other devices' clock signals. One device in your setup must be the clock leader, the other devices must be followers and receive the clock signal from the clock leader.
• Every device with digital I/O will have an internal clock and should have the option to be a clock leader or a clock follower.

Setup 1 – Scarlett 18i16 as a Clock Follower

This is the most basic setup and involves one expansion device, increasing the channel count of your Scarlett 18i16.

We've outlined the steps for an ADAT expansion device, but the same theory applies for S/PDIF expansion devices. Depending on which S/PDIF type you are using (coaxial or optical) you may need to change your Digital IO Mode settings in Focusrite Control 2.

Equipment:

• An external ADAT preamp - such as a Clarett+ OctoPre.
• One TOSLINK cable (also referred to as an ADAT cable).

Setup:

1. Connect the TOSLINK cable from the ADAT preamp's ADAT Out port to the ADAT In port on the Scarlett 18i16.
2. Set the ADAT preamp clock to Internal and your chosen sample rate.
3. In Focusrite Control 2, set the Scarlett 18i16 clock to ADAT and match the sample rate to the ADAT preamp.
4. In your DAW, set your channels to inputs 13 - 20, these are the eight ADAT inputs.

Setup 2 – Scarlett 18i16 as a Clock Leader

This is similar to Setup 1; however, it involves more cables. It's useful if you only use your expansion device occasionally, so you'd prefer to keep your Scarlett 18i16 as your clock leader.

We've outlined the steps for an ADAT expansion device, but the same theory applies for S/PDIF expansion devices. Depending on which S/PDIF type you are using (coaxial or optical) you may need to change your Digital IO Mode settings in Focusrite Control 2.

Equipment:

• An external ADAT preamp - such as a Clarett+ OctoPre.
• Two TOSLINK cables (also referred to as an ADAT cable).

Setup:

1. Connect the TOSLINK cable from the ADAT preamp's ADAT Out port to the ADAT In port on the Scarlett 18i16.
2. Connect a second TOSLINK cable from the Scarlett 18i16's ADAT Out to the ADAT preamp's ADAT In. This cable is just to send clock data, but if your ADAT preamp has outputs, you can also send signals back out of your computer to gain extra analogue outputs.
3. Set the ADAT preamp clock to ADAT and your chosen sample rate.
4. In Focusrite Control 2, set the Scarlett 18i16 clock to Internal and match the sample rate to the ADAT preamp.
5. In your DAW, set your channels to inputs 13 - 20, these are the eight ADAT inputs.

Setup 3 – Using more than one expansion device

In this setup, we're using two expansion devices: an ADAT device and an S/PDIF device. For ADAT, you might use a preamp like an OctoPre or a mic preamp. For S/PDIF, you could connect another interface in standalone mode or a guitar amp modeller.

Using the Scarlett 18i16 as your clock leader is useful if you only use your expansion devices occasionally, so don't need to turn them on every time you use your Scarlett 18i16.

Equipment:

• An external ADAT preamp - such as a Clarett+ OctoPre.
• A S/PDIF device - such as a guitar amp.
• Two ADAT cables.
• Two S/PDIF cables.

Setup:

1. Connect the TOSLINK cable from the ADAT preamp's ADAT Out port to the ADAT In port on the Scarlett 18i16. Connect the S/PDIF cable from the S/PDIF device's S/PDIF Out to the S/PDIF In on the Scarlett 18i16.
2. Connect a second TOSLINK cable from the Scarlett 18i16's ADAT Out to the ADAT preamp's ADAT In. Connect a second S/PDIF cable from the Scarlett 18i16's S/PDIF Out to the S/PDIF device's S/PDIF In.
3. Set the S/PDIF preamp clock to S/PDIF and your chosen sample rate. Some S/PDIF devices don't allow you to change these settings.
4. Set the Scarlett 18i16's clock to internal and match the sample rate.
5. Set the ADAT preamp to clock to ADAT and match the sample rate (it's getting its clock from the Scarlett 18i16 via the second ADAT cable).

Headphone Outputs

Your Scarlett 18i16 has two headphones outputs. Both headphones outputs are completely independent of the other analogue outputs, so they can have their own dedicated mix.

The headphone outputs are 6.35mm (¼”) TRS jacks. Many headphones have a 3.5mm TRS jack, to connect them to your Scarlett 18i16 you must use a TRS 6.35mm to 3.5mm adaptor.

The controls above the headphone outputs control the level going to your headphones.

Headphone Output Routing – you can assign any sources to your headphones, either using a Mix for an independent combination of hardware inputs (direct monitoring) and software playback channels, or directly routing a source, for example Software Playback 1-2.

To set up your headphone routing:

1. Open Focusrite Control 2.
2. Go to the Routing tab.
3. Find your headphones output in the Output list.
4. Click the corresponding Source dropdown and choose the source or mix you want to send to your headphones.

The mix you've created is now being sent to the headphones output you selected. You can control the overall level using the headphones control on the Scarlett or in software. You can control different parts of the mix using the Mix in Focusrite Control 2.

Your Scarlett 18i16's back panel in depth

This section covers all the features on your Scarlett 18i16's back panel, what they do, how you might use them and how they work in Focusrite Control 2.

USB Connection

The USB Type-C port labelled USB is to connect your Scarlett to your computer.

Use the included USB-C cable to connect to a USB-C port on your computer, or use the USB-C to A adaptor to connect to a USB-A port on your computer.

S/PDIF IO

The S/PDIF ports give you two channels of digital I/O to connect to other audio equipment with S/PDIF I/O such as guitar amps, mic preamps or any device with an S/PDIF output.

There are many ways to connect and clock your Scarlett 18i16 when you're using an external device connected via S/PDIF. For information on clocking and digital IO setups, please see the Sync Status section.

The Sync Status Indicator on your Scarlett 18i16 should light green. When you send audio from the external device to your Scarlett 18i16 you should see the S/PDIF channels coming in on channels 11-12.

Optical input and output

The two Optical ports (input and output) give you eight channels of digital ADAT I/O, to connect to other audio equipment with ADAT I/O such an eight-channel mic preamps.

There are many ways to connect and clock your Scarlett 18i16 when you're using an external device connected via it's optical ports. For information on clocking and digital IO setups, please see the Sync Status section.

The Sync Status Indicator on your Scarlett 18i16 should light green.

MIDI

The Scarlett 18i16 MIDI In and Out ports allow you to use your Scarlett as a USB MIDI interface. MIDI IN receives MIDI signals from keyboards or controllers; MIDI OUT sends MIDI information to Synths, Drum machines or MIDI-controllable equipment.

The MIDI IO doesn't require any setup for you to use your Scarlett 18i16 as a USB MIDI interface. The Scarlett 18i16's MIDI ports appear in your MIDI-enabled software, and you can either send or receive MIDI data between your computer and MIDI hardware via the Scarlett's 5-pin DIN MIDI ports.

Speaker Outputs

Outputs 1 and 2 are line-level outputs to connect your Scarlett 18i16 to an amplifier or active monitors. The outputs are balanced 1/4" TRS jack outputs, you can use them with either unbalanced TS or balanced TRS jack cables and connect to speakers with 1/4" jack, RCA or XLR inputs.

Your Scarlett 18i16's front panel Output dial controls the level sent to Outputs 1 and 2.

Line Outputs

Line Outputs 3-4 have identical electrical characteristics to the Monitor line Outputs 1 to 2 but aren't controlled by the Output control.

You can set the signals available at these outputs using Focusrite Control 2, and use the outputs to drive additional speakers in a multichannel monitoring system, such as a subwoofer or to send signals to outboard effects processors.

This section covers some common use cases for the Scarlett 18i16. Often your use case is a variant of these and how you use your Scarlett 18i16 probably reuses some principles.

The following diagram shows an electronic music set up with some mono and stereo synths, and a drum machine. Your setup might look a little different, but the principles are the same.

1. A stereo synth connected using two 6.35mm (1/4") TRS jack cables.
2. A stereo drum machine connected using two 6.35mm (1/4") TRS jack cables.
3. A mono synth connected using two 6.35mm (1/4") TRS jack cables.
4. A second mono synth, connected using two 6.35mm (1/4") TRS jack cables.
5. Headphones for you to monitor your performance.
6. A second set of headphones if you need them, or you could use this second headphone output for recording, see the Tip below.

This diagram shows which drums you might want to record to each of your Scarlett 18i16's inputs:

1. Kick
2. Snare
3. Overhead Left
4. Overhead Right
5. Engineer's headphones
6. Drummer's headphones.

This diagram shows the sort of instruments you might want to record in this type of recording scenario and how you can make use of the inputs on your Scarlett 18i16.

1. Stereo mic setup - when you're recording a more intimate session to create a sense of space, you might want to begin with a stereo microphone setup, for example:
   • Stereo microphones on a singer-songwriter's guitar.
   • Stereo microphones on a piano.
   • Stereo microphones in front of the whole band.
2. Individual instrument microphone - You could use this to mic up a single instrument, voice, or amplifier.
3. Vocal microphones - a microphone for your main vocalist.
4. Line inputs - Use the line inputs for any other instruments that aren't strictly acoustic, such as a 'line output' of a bass amp, or line outputs of an electric keyboard.
5. Engineer's headphones - Use these headphones to monitor what you're recording.
6. Artist headphones - often if the band is performing live, you won't need to give them headphones. However, if anyone wants to play to a backing track, metronome, or needs monitoring, you could use the second headphone output for the artist.

• Increasing the number of preamps on another interface or mixer that has run out of microphone preamps, for example:
  • Using any spare line inputs on the other interface. For example, by routing the Scarlett's microphone inputs to its line outputs.
• To use your studio setup without having your computer turned on or plugged in, for example, to use your guitar through your speakers, or any electronic music equipment connected.

To setup Standalone mode:

1. Connect your Scarlett's power socket to mains power.
2. Connect your Scarlett 18i16 to a computer running Focusrite Control 2. In Focusrite Control 2's mixer page route the Scarlett 18i16's inputs to the outputs you'd like to use. See Using the Focusrite Control 2 Mixer tab.
3. Disconnect your Scarlett 18i16 from your computer and it continues to pass audio in standalone mode.
4. Connect your inputs and outputs to your interface as usual.

• Sampling: You can record sounds back into your software to use as samples in your music.
• Podcasting: You can use loopback to record online interviews or discussions, where you want to capture both your voice and the voices of remote participants.
• Live Streaming: It's useful for streaming content with accompanying audio from your computer, such as gameplay, presentations, or tutorials.
• Screen Recording: When creating video tutorials or screencasts, loopback allows you to include the sound produced by your computer along with your narration.

To use Loopback, with your Scarlett:

1. Open your DAW or recording software.
2. Create a new recording channel in your DAW and either mute, or set the output to 'none' for this channel. It's important to do this so you don't cause a feedback loop.
3. Set your recording input of the muted channel to the Loopback channels of your Scarlett 18i16, channels 9-10.
4. Start recording.

The channels in your recording software receive the output of your Scarlett. You can use other channels in your recording software to record anything connected to the inputs on your Scarlett alongside the Loopback feed.

These specifications allow you to compare your Scarlett 18i16 with other devices and make sure they'll work together. If you're not familiar with these specifications, don't worry you don't need to know this information to use your Scarlett 18i16 with most devices.

Scarlett 18i16 Performance Specifications

Where possible, we measure all performance figures following AES17.

Scarlett 18i16 Physical and Electrical Characteristics

Single-band - 44.1kHz and 48kHz

Dual-band - 88.2kHz and 96kHz

Quad-band - 176.4kHz and 192kHz

Troubleshooting

For all troubleshooting queries, please visit the Focusrite Help Centre at support.focusrite.com.

Copyright & Legal Notices

Focusrite is a registered trademark and Scarlett is a trademark of Focusrite Group PLC.

All other trademarks and trade names are the property of their respective owners.

2025 © Focusrite Audio Engineering Limited. All rights reserved.

Focusrite would like to thank the following Scarlett 4th Gen team members for their hard work in bringing you this product:

Aarron Beveridge, Adam Watson, Adrian Dyer, Adrien Fauconnet, Alex Middleton-Dalby, Alice Rizzo, Alistair Smith, Andy Normington, Andy Poole, Andy West, Arne Gödeke, Bailey Dayson, Bamber Haworth, Bash Ahmed, Ben Allim, Ben Bates, Ben Cochrane, Ben Dandy, Benjamin Dunn, Bran Searle, Callum Denton, Carey Chen, Cerys Williams, Chris Graves, Dan Clarke, Dan Stephens, Dan Weston, Daniel Hughley, Daniel Johnson, Danny Nugent, Dave Curtis, David Marston, Derek Orr, Ed Fry, Ed Reason, Eddie Judd, Ellen Dawes, Emma Davies, Flavia Ferreira, Greg Westall, Greg Zielinski, Guillem Allepuz, Hannah Williams, Harry Morley, Hasan Saeed, Ian Hadaway, Isaac Harding, Jack Cole, Jack Holyoak, Jake Wignall, James Hallowell, James Otter, Jason Cheung, Jed Fulwell, Jerome Noel, Jesse Mancia, Joe Crook, Joe Deller, Josh Wilkinson, Joe Munday, Joe Noel, Jon Jannaway, Julia Laeger, Kai Van Dongen, Keith Burton, Kiara Holm, Kieran Rigby, Krischa Tobias, Lars Henning, Laurence Clarke, Loz Jackson, Luke Piotrak, Luke Mason, Marc Smith, Mark Greenwood, Martin Dewhirst, Martin Haynes, Mary Browning, Massimo Bottaro, Matt Morton, Matt Richardson, Max Bailey, Michalis Fragkiadakis, Mick Gilbert, Mike Richardson, Nicholas Howlett, Nick Lyon, Nick Thomson, Oliver Tapley, Olly Stephenson, Paul Chana, Paul Shufflebotham, Pete Carss, Pierre Ruiz, Richard Carvalho, Richard Walters, Robert Blaauboer, Robert Mitsakov, Ross Chisholm, Sam Lewis, Samuel Price, Sandor Zsuga, Sebastian Heinz, Simon Burges, Stefan Archer, Stefan Elmes, Steve Bush, Stratis Sofianos, Taavi Bonny, Taren Gopinathan, Tom Carter, Tom Haines, Tony Pow, Valeria Cirillo, Will Hoult, Will Munn, Will Thomas, Vidur Dahiya, Wade Dawson, Zih-Syuan Yang.

Authored by Ed Fry.