Focusrite Clarett 4Pre USB User manual

focusrite.com
Version 2
User GuideUser Guide

2
TABLE OF CONTENTS
OVERVIEW..................................................................... 3
Introduction .................................................................3
Features ....................................................................4
Box Contents ................................................................5
System Requirements .........................................................5
Getting Started................................................................. 6
Software Installation ..........................................................6
Registering your Clarett USB ...................................................6
Hardware Features ...........................................................8
Front Panel ....................................................................8
Rear Panel ....................................................................9
Connecting your Clarett 4Pre USB ..............................................10
Computer audio setup ..........................................................10
Audio Setup in your DAW ........................................................10
Connecting Clarett 4Pre USB to loudspeakers ......................................11
Examples of Usage ..........................................................13
1. Recording a small band .......................................................13
2. Recording a drum kit with (and without) the optical connection ......................15
3. Providing foldback while recording..............................................17
FOCUSRITE CONTROL - OVERVIEW...............................................18
CLARETT 4PRE USB TECHNICAL SPECIFICATIONS .................................19
Performance Specications ...................................................19
Physical and Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
TROUBLESHOOTING ...........................................................21
COPYRIGHT AND LEGAL NOTICES ................................................21

3
OVERVIEW
WARNING: Excessive sound pressure levels from earphones and headphones can cause
hearing loss.
WARNING: This equipment is only compatible with USB Type 2.0, 3.0 or 3.1 ports, or Thunderbolt™ 3
ports. More information regarding the compatibility of computer serial ports can be found at:
support.focusrite.com/hc/articles/115002287829-USB-port-clarication-and-compatibility
Introduction
Thank you for purchasing this Clarett 4Pre USB, one of the family of Focusrite professional USB
audio interfaces incorporating newly-designed, high quality Clarett analogue pre-ampliers with
the unique AIR function. In conjunction with the Focusrite Control application, you now have a highly
versatile and professional solution for routing high quality audio to and from your computer recording
system, with super-low latency.
You can also use the Clarett 4Pre USB as a “stand-alone” interface on-stage, bringing the benets of
Focusrite’s high-quality analogue microphone preamps to your live performance.
This User Guide provides a detailed explanation of the hardware to help you achieve a thorough
understanding of the product’s operational features. We recommend you take the time to read
through the Guide, whether you’re new to computer-based recording or a more experienced user, so
you are fully aware of all the possibilities the Clarett 4Pre USB has to offer.
IMPORTANT: As well as this User Guide, you will need the Focusrite Control Software
Guide which can be downloaded from:
focusrite.com/downloads.
This contains full details of Focusrite Control, the software application that has been
designed specically for use with the Focusrite Clarett USB range of interfaces.
If either User Guide does not have the information you need, please go to support.focusrite.com,
where you can nd articles and tutorials beyond the scope of this user guide. A Getting Started video
tutorial is also available, at focusrite.com/get-started.

4
Features
The Clarett 4Pre USB audio interface provides the means for connecting microphones, musical
instruments, line level audio signals and digital audio signals to a computer through the computer’s
USB port. The signals at the physical inputs can be routed to your audio recording software / digital
audio workstation (referred to throughout this user guide as the “DAW”); similarly, the outputs from
the DAW can be congured to appear at the unit’s physical outputs.
Audio sources – mics, instruments, etc., can be recorded into your DAW and then played back
from there through ampliers and speakers, powered monitors, headphones, a mixer or any other
analogue or digital audio equipment you wish to use.
The Clarett 4Pre USB is also a MIDI interface, allowing your computer to connect to other MIDI
equipment in your studio.
An important feature of the Clarett 4Pre USB is the analogue preamplier design. In addition to
their class-leading dynamic range and ability to provide all the gain you’re ever likely to need,
the circuitry now includes an exciting new AIR function. Individually selectable on each channel,
AIR subtly modies the pre-amp’s frequency response to model the impedance and resonance
characteristics of Focusrite’s classic transformer-based ISA mic preamps. When recording with
good quality microphones, you will notice an enhanced clarity and denition in the important mid
frequency range, just where it is most needed for vocals and many acoustic instruments.
The accompanying software application, Focusrite Control, is designed to require a minimal amount
of user interaction, letting you easily congure the Clarett 4Pre USB with signal routings appropriate
for the most common recording tasks. For more complex situations, it provides extensive routing
and monitoring options, as well as the ability to control global hardware settings such as sample rate
and synchronisation. You can download Focusrite Control from:
focusrite.com/downloads
iPad and iPhone users can additionally download Focusrite iOS Control from the App Store®. The
app communicates via WiFi with Focusrite Control running on your computer, and lets you adjust
your monitor mixes from your iOS device. For more information, see:
support.focusrite.com/hc/en-gb/articles/212028389-Focusrite-iOS-Control-Basic-setup

5
Box Contents
Along with your Clarett 4Pre USB you should have:
• External 12 V DC mains Power Supply Unit (PSU)
• USB-C to USB-A cable
• USB-C to USB-C cable
Focusrite Control is available at focusrite.com/downloads. On Windows, Focusrite Control will
also install the driver required. Mac users: Clarett 4Pre USB is class-compliant on Macs, therefore
no drivers are required.
As a Clarett owner, you are also entitled to a selection of third-party software. To nd out what’s
included, go to:
focusrite.com/usb-c-audio-interface/clarett-usb/clarett-4pre-usb
System Requirements
IMPORTANT – Please visit the following link for up-to-date information on computer and
operating system compatibility for all Clarett products:
support.focusrite.com

6
GETTING STARTED
Software Installation
Focusrite Control and the driver software needed for the Clarett USB are available for download
from the Focusrite website: focusrite.com/downloads.
Click Clarett USB range on the Downloads page. This will take you to a page with all the downloads
which are available for the Clarett USB range.
To download the Focusrite Control version you need, click the appropriate Download button.
Note that the Windows driver is included within the Focusrite Control download. No additional
driver is needed for Macs.
Registering your Clarett USB
If you are having trouble with the steps below, please watch our video guide here:
focusrite.com/get-started
1. Go to focusrite.com/register
2. If you do not have already have a Focusrite/Novation account, select CREATE AN ACCOUNT and
follow the on-screen instructions.

7
3. If you do have an account, log in and select REGISTER A NEW PRODUCT:
4. Select your Clarett USB device from the Product drop-down list and enter your device’s Serial
Number at the bottom of the page. You can nd the serial number on the rear or underside of the
Clarett, and also on the gift box. Then click Set Serial Number.
5. Follow the rest of the on-screen instructions to nish registering your device.
6. When registration is complete, your Product will appear in your Account under the
My Hardware tab.
7. All your bundled software can be found under the My Software tab in your account.

8
Hardware Features
Front Panel
2 1 1 11
4
2 8 9 9
3 355 3 10 6 75 43 5
The front panel includes input gain and monitoring controls as well as four of the input connectors
for Mic, Line and Instrument signals.
1. Inputs 1 to 4 – Combo XLR input sockets for each channel - connect microphones via XLR
connectors, or line level signals via ¼” jacks. Instruments (e.g., guitar) may also be connected
via ¼” jacks to Inputs 1 and 2. Either TRS (balanced) or TS (unbalanced) jack plugs can be
used for instruments or line level signals.
2. 48V – two switches enabling 48 V phantom power at the combo connectors’ XLR contacts for
mic inputs 1 & 2 and 3 & 4 respectively. Each switch has a red LED to show when phantom
power is enabled. Note that not all microphones require phantom power. If you are unsure
whether your microphone needs it to work, please read the microphone documentation.
3. Gain 1to 4– four rotary controls: adjust input gain for signals at Inputs 1 to 4 respectively. The
gain controls have LED ‘halos’ to conrm signal level: green indicates an input level of at least
-42 dBFS (i.e., ‘signal present’), the ring then turns orange when the signal level reaches -6
dBFS, and red at 0 dBFS.
4. INST – two red LEDs which illuminate when Instrument mode is selected for the jack Inputs
1 or 2 from Focusrite Control software. When Instrument mode is selected, the line input is
converted to a high impedance unbalanced input. You can connect instruments via a 2-pole
(TS) jack plug here.
5. AIR – four yellow LEDs – one per input - which illuminate when the AIR function is selected
for the input from Focusrite Control. AIR modies the frequency response of the input stage
to model the classic, transformer-based Focusrite ISA mic preamps.
6. (USB active) – a green LED which illuminates when the unit has established communication
with the computer to which it is connected.
7. (Locked) – a green LED which conrms clock synchronisation, either to the Clarett 4Pre
USB’s internal clock or to an external digital input.
8. MONITOR – main monitor output level control – this control will normally control the level
at the main monitor outputs on the rear panel, but can be congured in Focusrite Control to
adjust the level of either or both pairs of analogue outputs.
9. (Headphones) 1and 2 – connect headphones here. The stereo mixes at these outputs
are set up in Focusrite Control: Headphone 1 always carries the same mix as Line Outputs
3 and 4, while Headphone 2 can provide an independent mix by using Outputs 5 and 6 in the
software. Each headphone output has its own volume control.
10. POWER – green LED conrming DC power is connected.

9
Rear Panel
367 5
12
48 9
1. LINE INPUTS 5 to 8– four balanced analogue line inputs for Channels 5 to 8, on ¼” TRS jack
sockets. Connect further line level signals here using ¼” TRS (balanced) or TS (unbalanced)
jack plugs.
2. LINE OUTPUTS 1to 4– four balanced analogue line outputs on ¼” jack sockets; use TRS jacks
for a balanced connection or TS jacks for unbalanced. Line Outputs 1and 2will generally be
used for driving the main L and R speakers of your monitoring system, while Outputs 3 and 4
can be used for connecting additional line level equipment (e.g., outboard FX processors). The
signals routed to all the outputs may be dened in Focusrite Control.
3. OPTICAL INPUT – a TOSLINK connector carrying eight channels of digital audio in ADAT
format at 44.1/48 kHz sample rate or four channels at 88.2/96 kHz. This input is disabled at
176.4/192 kHz sample rates. This input is also capable of accepting a stereo optical S/PDIF
source.
4. – USB-C™ connector; connect the Clarett 4Pre USB to your computer with the supplied
USB-C to USB-C or USB-C to USB-A cable.
5. MIDI IN and MIDI OUT – standard 5-pin DIN sockets to connect external MIDI equipment. You
can send/receive MIDI data between your computer and external MIDI devices.
6. SPDIF IN and OUT – two RCA sockets carrying two-channel digital audio signals in or out of
the Clarett 4Pre USB in S/PDIF format. Like all the other inputs and outputs, the routing of
S/PDIF signals may be customised in Focusrite Control. The S/PDIF Input appears in Focusrite
Control as Inputs 9 and 10 and the S/PDIF Output as Outputs 7 and 8.
7. External DC power input – power the Clarett 4Pre USB via the separate AC adaptor (PSU)
supplied. The PSU is a 12 V DC unit rated at 2 A.
8. Power On/Off switch.
9. Kensington security slot– secure your Clarett 4Pre to a suitable structure if desired.

10
Connecting your Clarett 4Pre USB
The Clarett 4Pre must be powered using the supplied AC adaptor (PSU). Connect the PSU to the rear
panel power socket and turn the unit on with the power switch.
The Clarett 4Pre has a USB-C™ port (on the rear panel). Once the software installation is complete,
connect the Clarett 4Pre to your computer using one of the supplied USB-C cables.
Turn the unit on with the power switch.
Computer audio setup
When you connect your Clarett 4Pre USB to your computer for the rst time, you will need to select
the Clarett 4Pre USB as the audio input/output device.
• Mac OS: selection is made in System Preferences >Sound: select the Focusrite device on
both the Input and Output pages.
• Windows: selection is made in Control Panel >Sound: right-click on the Focusrite device
and select Set as Default Device in both Recording and Playback tabs.
In case of difculty, full details of how to select the Clarett 4Pre USB as the audio device on all
operating systems can be found at:
focusrite.com/get-started/clarett-4PreUSB
On all subsequent connections, your OS should automatically select the Clarett 4Pre USB as the
default audio device.
Audio Setup in your DAW
After installing the drivers and connecting the hardware, you can use the Clarett 4Pre USB with the
DAW of your choice.
Your DAW may not automatically select the Clarett 4Pre USB as its default I/O device. In this case,
you must manually select the driver on your DAW’s Audio Setup* page, and select Focusrite 4Pre
USB (Mac) or Focusrite USB ASIO (Windows). Please refer to your DAW’s documentation or Help
les if you are unsure where to select the Clarett 4Pre USB as your audio device.
* Typical name – page names may vary with DAW

11
Connecting Clarett 4Pre USB to loudspeakers
The 1/4” jack LINE OUTPUTS 1 and 2on the rear panel will normally be used to drive monitoring
speakers. Self-powered monitors incorporate internal ampliers, and may be connected directly.
Passive loudspeakers will require a separate stereo amplier; in this case, the outputs should be
connected to the amplier’s inputs.
Professional power ampliers will generally have balanced inputs. If your amplier or powered
speakers have balanced inputs, use 3-pole (TRS) ¼” jacks to connect them to the Clarett 4Pre USB.
All the line output connectors are 3-pole (TRS) ¼” jack sockets and are electronically balanced.
Typical consumer (hi-) ampliers and small powered monitors will have unbalanced inputs using
RCA sockets.
Connecting active speakers
Connecting passive speakers

12
When mixing, you can connect an additional pair of speakers (mid-eld, near-eld, etc.) to
LINE OUTPUTS 3 and 4 to check your mix on different types of speaker. You can easily congure
Focusrite Control to route the mix to these outputs as well as Outputs 1 and 2.
Main
Monitor
Speakers
Additional
Monitor
Speakers
IMPORTANT:
LINE OUTPUTS 1 and 2incorporate “anti-thump” circuitry that protects your speakers if
the Clarett 4Pre USB is turned on while the speakers (and amplier if used) are connected
and active.
LINE OUTPUTS 3 and 4do not have this circuitry.
If you’re using additional speakers connected to these outputs, we recommend you power
your Clarett 4Pre USB on rst,
then turn on the speakers or power amplier. But get into
the habit of following the general rule in any case - it is
always good audio practice to turn
on a speaker system of any kind
after turning on the equipment feeding it.

13
Examples of Usage
The Clarett 4Pre USB is an excellent choice for numerous recording and monitoring applications.
Some typical congurations are shown below.
1. Recording a small band
This setup illustrates a typical conguration for multitrack recording with DAW software on your
computer.
In this example we are making a live recording of a small, largely acoustic band, consisting of
electro-acoustic guitar, bass guitar, synth and two vocalists. Two microphones and the two guitars
are shown connected to the Clarett 4Pre USB’s front panel inputs. Note that only Inputs 1 and 2 can
be congured to accept instruments directly, so we have used these two inputs for the two guitars.
Ensure INST mode is selected for Inputs 1 and 2 from Focusrite Control, and the INST LEDs are
illuminated. The two mics for vocals are plugged into Inputs 3 and 4; if they are condenser mics,
press the 48V button to enable phantom power. The stereo line output from the synth is connected to
LINE INPUTS 5 and 6on the rear panel.
The engineer can monitor the recording via Headphone Output 1 if he/she wishes, using Focusrite
Control to set up his/her desired monitoring mix. A second, different mix can be created if necessary
and can be routed to Headphone Output 2.

14
A note about latency
You will probably have heard the term “latency” used in connection with digital audio systems. In the
DAW recording application described above, latency is the time it takes for your input signals to pass
through your computer and audio software, and back to you.
While not an issue for most recording situations, latency can be a problem for a performer who
wishes to record while monitoring their input signals. This might be the case if you need to increase
your buffer size, which could be needed when you record overdubs on a large project using many
DAW tracks, software instruments and FX plug-ins.
Common symptoms of a buffer setting that is too low could be glitching audio (clicks and pops), or a
particularly high CPU load within your DAW (most DAWs have CPU readouts). If you experience this
on a Mac, you can raise the buffer size from the DAW application itself; on a Windows PC you will
need to change this from the ASIO ControlPanel which can usually be accessed from your DAW
Setup Preferences*.
The Clarett 4Pre, in conjunction with Focusrite Control, allows “low latency monitoring”, which
overcomes this problem. You can route your input signals directly to the Clarett 4Pre’s headphone
and line outputs. This enables the musicians to hear themselves with ultra-low latency – i.e.,
effectively in “real time” – along with computer playback. The input signals to the computer are not
affected in any way by this setting. However, note that any effects being added to the live instruments
by software plug-ins will not be heard in the headphones in this case, although the FX will still be
present on the recording.
* Typical name – page names may vary with DAW

15
2. Recording a drum kit with (and without) the optical connection
In addition to the eight analogue inputs, the Clarett 4Pre USB has an ADAT input port (OPTICAL IN)
which can provide an additional 8 audio inputs at 44.1/48 kHz sample rate or four at 88.2/96 kHz.
Using a separate 8-channel microphone preamplier equipped with an ADAT output – such as the
Clarett OctoPre – provides a simple and excellent method of expanding the Clarett 4Pre USB’s input
capability. This could, for example extend the scope of the recording example above to include a
close-miked drum kit, as shown below.
The Clarett OctoPre’s OPTICAL OUT port is connected to the Clarett 4Pre USB’s OPTICAL IN port
with a single TOSLINK optical cable. The two devices must be synchronised to ensure audio passes
cleanly, without clicks and pops. This can be achieved by selecting ADAT as the clock source on the

16
Device Settings tab of Focusrite Control. The two devices must be set to operate at the same
sample rate.
The additional inputs realised by use of the optical port may be routed using Focusrite Control
in exactly the same manner as the other inputs. The additional inputs can also form part of any
musician’s headphone mix, as required.
If an ADAT-equipped mic pre-amp is not available, a satisfactory method of recording drums with
four mics and the Clarett 4Pre USB is shown below:

17
3. Providing foldback while recording
While recording, musicians will often prefer to hear themselves along with the other players, and
when overdubbing, the tracks that have already been recorded. A mix created for this purpose, which
the musician can hear on headphones while performing, is called foldback.
Focusrite Control lets you dene several different mixes, each of which may be either mono or stereo,
and which may be routed to any of the Clarett 4Pre USB’s outputs. This enables individual musicians
to have a foldback mix optimised to their own requirements. In this way, each foldback feed can
be made up from a different mix of a musician’s own input, the live contributions from the other
performers, and DAW tracks which have already been recorded. See the Focusrite Control Guide for
details of how to congure different mixes, and how to route them to the Clarett 4Pre USB’s various
outputs.
Each of the headphone outputs on the front panel initially provide a default mix: Headphone 1’s mix
is always the same stereo mix that is routed to Line Outputs 3 and 4, while Headphone 2 has an
independent mix dedicated for headphone monitoring use. You can adjust both mixes in Focusrite
Control - that for Outputs 3/4 denes what is heard by Headphones 1, and that for Outputs 5/6 (which
have no corresponding rear panel sockets) denes what is heard by Headphones 2.
Either or both of these may be used for foldback mixes; each output can drive a pair of headphones
directly. This is the easiest method, and has the advantage that the mixes are stereo. If you need to
drive additional pairs of headphones, you’ll need to include an external headphone amplier as part
of your set-up:
Headphone Distribution Amplifier
Always remember - when sourcing monitor mixes from input signals, ensure the DAW channels on
which you are recording are muted, otherwise the musicians will hear themselves “twice”, with one
signal audibly delayed as an echo.

18
FOCUSRITE CONTROL - OVERVIEW
Focusrite Control is the software application used with the Clarett 4Pre, which can be downloaded
from focusrite.com/downloads. An iOS app allowing WiFi control of Focusrite Control is also
available, from the Apple App Store.
Focusrite Control allows you to create a custom monitor mix for each musician, and specify the
routing of all audio signals to the physical audio outputs. Sample rate and clock source selection are
also available from Focusrite Control.
Focusrite Control has its own, dedicated User Guide, which has detailed operating
instructions for all aspects of the software. This may be downloaded from:
focusrite.com/downloads.

19
CLARETT 4PRE USB TECHNICAL SPECIFICATIONS
Performance Specifications
Configuration
Inputs 18: analogue (8), S/PDIF (2), ADAT (8)
Outputs 8: analogue (4), S/PDIF (2), HP (2)
Mixer Fully assignable 26-in/10-out mixer
Custom mixes 10 mono
Maximum custom mix inputs 18 mono
Digital Performance
Supported sample rates 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz & 192 kHz
Microphone Inputs
Frequency Response 20 Hz - 35 kHz +/-0.5 dB at minimum gain
Dynamic Range 118 dB
THD+N 0.0009%
Noise EIN <–128 dB (A-weighted)
Maximum input level +18 dBu at minimum gain
Gain Range 57 dB
Line Inputs 1-4 (Variable Gain)
Frequency Response 20 Hz - 35 kHz +/-0.5 dB at minimum gain
Dynamic Range 118 dB
THD+N 0.001%
Maximum input level +26 dBu at minimum gain
Gain Range 57 dB
Line Inputs 5-8 (Fixed Gain)
Frequency Response 20 Hz - 35 kHz +/-0.5 dB
Dynamic Range 118 dB
THD+N 0.001%
Maximum input level +18 dBu
Instrument Inputs
Frequency Response 20 Hz - 35 kHz +/-0.5 dB at minimum gain
Dynamic Range 117 dB
THD+N 0.001%
Maximum input level +14 dBu at minimum gain
Gain Range 57 dB

20
Line & Monitor Outputs
Dynamic Range 118 dB
THD+N 0.0006%
Maximum Output Level (0 dBFS) +18 dBu, balanced line/TRS outputs
Headphone Outputs
Dynamic Range 115 dB (A-Weighted)
THD+N 0.0003% >100R
Maximum Output Level +15 dBu >100R
Physical and Electrical Characteristics
Analogue Inputs 1 to 4
Connectors Combo XLR sockets: Mic/Line/Inst (Inputs 1 & 2); Mic/Line
(Inputs 3 & 4) on front panel
Mic/Line switching Automatic
Line/Instrument switching
(Inputs 1 & 2) via Focusrite Control
Phantom power +48 V switches for inputs 1 & 2, 3 & 4
Analogue Inputs 5 to 8
Connectors 4 x balanced ¼” TRS jacks, on rear panel
Analogue Outputs
Main outputs 4 x balanced ¼” TRS jacks, on rear panel
Stereo headphone outputs 2 x ¼” TRS jack on front panel
Main monitor output level control On front panel
Headphones level controls
Other I/O
ADAT Input
TOSLINK optical connector:
8 channels at 44.1/48 kHz
4 channels at 88.2/96 kHz
Optical S/PDIF input (selectable)
S/PDIF I/O 2 x RCA
Data connector (to computer) 1 x USB-C™ connector
MIDI I/O 2 x 5-pin DIN sockets
Weight and Dimensions
W x D x H 222 mm x 192 mm x 63.5 mm / 8.74” x 7.56” x 2.5”
Weight 1.35 kg
2.98 lbs