Focusrite LiquidControl User Manual
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LiquidControl™ Software
Please visit www.focusrite.com to download the latest version of the free LiquidControl™
software application, for Mac OS X or Windows XP. The application allows you to edit The
Liquid Channel™ remotely, plus load, save and archive the mic-pre and compressor replicas
and programs. The LiquidControl™ user guide is also available to download in PDF format.
Contents
Introduction ............................................................................ 1
Important Safety Instructions ............................................. 1
Power Connections.............................................................. 1
Liquid Channel™ Architecture ......................................... 2
Rear Panel Connections ......................................................3
Front Panel Controls............................................................ 3
Mic-Pre and A/D.................................................................... 4
Session Saver ..........................................................................4
Clock Select and Synchronisation..................................... 5
Main LCD and Controls ...................................................... 5
Harmonics ............................................................................... 6
Compressor Settings............................................................ 6
3-Band EQ ............................................................................... 7
Comp & EQ Settings ............................................................8
Data Select .............................................................................. 8
Linking Multiple Units.........................................................10
Connections and Applications .........................................11
Frequently Asked Questions............................................16
Specifications ........................................................................21
Disclaimer .............................................................................22
Accuracy ................................................................................ 22
Copyright ..............................................................................22
Warranty ............................................................................... 22
Introduction
Thank you for purchasing The Liquid Channel™
brought to you by the Focusrite team – Ian, Trevor,
Peter, Martin, Tom, Mick A’C, Phil, Chris G, Micky,
Pauline, Melissa, Chris W, Rob J Snr, Simon J, Vernon,
Giles, Rob J Jnr, Mick G, Tim, Dave, Nick, Paul, Peter
and Simon.
The chaps at Focusrite are a jolly hard working bunch
and take a great deal of pride in designing, building and
delivering products which are considered the best
audio units around; we hope your new Focusrite unit
lives up to that reputation and that you enjoy many
years of productive recording. If you would like to tell
us about your recording experiences then email us at:
sales@focusrite.com
The Focusrite Team
Important Safety Instructions
Please read all of these instructions and save them for future
reference. Follow all warnings and instructions marked on
the unit.
• Do not obstruct air vents in the rear panel. Do not
insert objects through any apertures. Ensure adequate
ventilation at all times.
• Do not use a damaged or frayed power cord.
• Unplug the unit before cleaning. Clean with a damp
cloth only. Do not spill liquid on the unit.
• Unplug the unit and refer servicing to qualified service
personnel under the following conditions: if the power
cord or plug is damaged; if liquid has entered the unit; if
the unit has been dropped or the case damaged; if the
unit does not operate normally or exhibits a distinct
change in performance. Adjust only those controls that
are covered by the operating instructions.
• Do not defeat the safety purpose of the polarised or
grounding type plug. A polarised plug has two blades
with one wider than the other. A grounding type plug
has two blades and a third grounding prong. The wider
blade or the third prong are provided for your safety.
When the plug provided does not fit into your outlet,
consult an electrician for replacement of the obsolete
outlet.
This unit is capable of operating over a range of mains
voltages as marked on the rear panel. Ensure correct mains
voltage setting and correct fuse before connecting mains
supply. Do not change mains voltage settings while mains
supply is connected. To avoid the risk of fire, replace the
mains fuse only with the correct value fuse, as marked on
the rear panel. The internal power supply unit contains no
user serviceable parts. Refer all servicing to a qualified
service engineer, through the appropriate Focusrite dealer.
WARNING:
THIS UNIT MUST BE EARTHED BY THE
POWER CORD. UNDER NO
CIRCUMSTANCES SHOULD THE MAINS
EARTH BE DISCONNECTED FROM THE
MAINS LEAD.
Power Connections
There is an IEC mains lead supplied with the unit, which
should have the correct moulded plug for your country. The
wiring colour code used is:
For units shipped to the USA, Canada, Taiwan and Japan:
Live Black; Neutral White; Earth Green
For units shipped to any other country:
Live Brown; Neutral Blue; Earth Green & Yellow
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Liquid Channel™ Architecture
The Liquid Channel™ is fundamentally different from
any other Focusrite product previously built – and
indeed any other dynamics processor currently
available. Although The Liquid Channel™ is extremely
simple to use, please take a moment to read this
section of the user guide, which gives a brief overview
of the signal path and storage capabilities of the unit.
Overview
The Liquid Channel™ is the first implementation of
Focusrite’s groundbreaking ‘Liquid Technology’. The
Liquid Channel™ transports classic front-end
processing into the digital age, removing the need for
endless patching and adding fluidity and reliability to
the studio environment. Quite simply, The Liquid
Channel™ is capable of being configured to replicate
the finest mic-pres and compressors in history, all
inside a single 192 kHz, 2U device.
This is achieved through a unique two-part process.
Firstly, the use of Dynamic Convolution techniques is
applied, utilising lightning fast SHARC chips applying
unique level-dependent impulse responses to every
sample of audio. However, whilst this is more than
sufficient to closely emulate a compressor’s sonic
behavior, in order to replicate subtle nuances of
classic units, the pre-amplifier must operate in a
suitable physical environment to mirror the way in
which any classic unit interacts with a given
microphone. The Liquid Channel™’s solution to this
problem lies in its vast analogue front-end. The preamp has the ability to change its impedance and vary
its signal path to either transformer or electronic,
replicating the interaction characteristics of the
original, whilst remaining transparent within the signal
path.
The Liquid Channel™ can therefore closely replicate
the sound of the classic mic-pres and compressors
from history. With entirely digital front panel controls,
all parameters can be saved in one of 100 program
memories, meaning that entire session setups can all
be recalled at the touch of a button. A brand new
digital EQ is also available, providing a comprehensive
and truly ‘liquid’ channel strip.
A USB connection on the rear panel links to the
LiquidControl™ software application, enabling the
archiving of both replicas and surplus program
memories, as well as providing full editing and remote
operation of the unit itself. The Liquid Channel™
comes complete with replicas of 40 classic mic-pres
and forty classic compressors but is infinitely
expandable, since the USB port also facilitates the
upload of further replicas downloaded from a
dedicated website –
www.focusrite.com.
Finally, to account for variances in amounts of second,
third and fifth order harmonic distortion (usually
perceived as warmth) from one pre-amp to the next, a
dial is included to permit control over this value. This
essential feature ensures satisfaction for even the most
hardcore vintage enthusiast, bringing accurate control
over the key sonic attributes.
Liquid Assets
The Liquid Channel™ ships with 40 pre-amp replicas
and 40 compressor replicas as standard. The free
LiquidControl™ software allows additional replicas
downloaded from
www.focusrite.com to be
uploaded to The Liquid Channel™ via USB.
Program memories
The Liquid Channel™ has 100 program memories to
allow storage of preferred pre-amp/compressor/EQ
combinations. These can be saved, archived and
reloaded from a remote computer using
LiquidControl™ via the USB connection. All channel
parameters are stored, offering ‘total recall’ including
mic gain. Using LiquidControl™, a virtually unlimited
number of replicas and programs can be stored on
your PC or Mac and uploaded to The Liquid
Channel™ hardware as required. You can also email
your favourite Liquid Channel™ replicas and program
settings to other users anywhere in the world – the
ultimate in session recall.
Signal Path
The Liquid Channel™ features both analogue (mic and
line) and digital (AES-EBU) inputs, plus analogue (line)
and digital (AES-EBU) outputs. Analogue signals
connected to the mic input are routed through an
analogue mic-pre stage, before passing through an A/D
and entering the digital pre-amp convolution section.
The unique sonic characteristics of the selected preamp replica are then applied to the signal. The signal
then passes through the compressor and EQ sections
(in that order, unless the EQ ‘Pre Comp’ switch has
been engaged – see page 7 for details). This processed
signal then routes to the digital output, and via the
D/A to the analogue output.
Analogue signals connected to the line input follow the
same signal path as above, but bypass the initial micpre stage routing directly to the A/D. The pre-amp
type will be fixed at FLAT trfmr (transformer) whilst
the line input is selected on the front panel. Digital
signals connected to the digital input are routed
directly to the pre-amp convolution section. However
this can be bypassed – see ‘Pre-amp and Compressor
Select’ on page 5 for details.
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Rear Panel Connections
XLR Audio Inputs and Output
All 3-pin XLR audio connectors (MIC I/P, LINE I/P and
LINE O/P – from left to right above) are wired as
follows:
Pin 1: Screen/Chassis
Pin 2: Audio 0°
Pin 3: Audio 180°
AES Input and Output
The AES I/P and AES O/P XLR connectors provide
The Liquid Channel™ with AES-EBU format digital
input and output. See pages 11-15 for details of digital
applications and connectivity.
Wordclock Input and Output
The WORDCLOCK INPUT BNC connector allows
The Liquid Channel™ to be linked to an external
clock source. The WORDCLOCK OUTPUT BNC
connector allows The Liquid Channel™ to supply a
clock source to external equipment. See page 9 for
more details on synchronising The Liquid Channel™
to an external Wordclock source.
Dynamic Link Bus
The DYNAMIC LINK BUS connectors allow two or
more units to be linked together for stereo and multichannel applications, whereby one unit (the ‘master’)
will control the settings on multiple units. In addition,
if using multiple units in digital stereo pairs, the
dynamic link connectors also transmit digital audio
data between devices. The connectors are both RCA
(phono). See page 10 for more details on linking
multiple units.
USB
The USB connector allows The Liquid Channel™ to
be connected to a computer running the free
LiquidControl™ software, which allows remote
operation, download and archive management. See the
separate LiquidControl™ user guide, downloadable
from
www.focusrite.com, for more information. For
remote operation at a greater distance (up to 45m),
contact Focusrite for information about purchasing a
USB to CAT5 (Ethernet) converter.
Front Panel Controls
Digital controls
The dials are all tactile rotary encoders, meaning that
they can be rotated infinitely and their relative value
will be displayed (except for the DATA wheel) by the
LEDs surrounding them. The exact numerical
parameter values can be seen on the large display
when active, in the centre of the front panel.
As all controls are digital, the settings can be saved
and recalled with ease, and edited from the
LiquidControl™ software application (please see the
separate LiquidControl™ documentation, available
from
www.focusrite.com for details). N.B. The
hardware's onboard memory will store the last frontpanel settings to have been left standing on the unit
for over 10 seconds while powered up, while the unit
is turned off.
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Power
Applies power to the unit. Turn on The Liquid
Channel™ before powering up devices to which the
outputs are connected.
Mic-Pre and A/D
Meter
A single, vertical, peak hold LED bar graph displays the
level of the signal being fed from the mic-pre to the
A/D converter, controllable by the gain dial in the micpre section. The scale shows from –20 dBFS up to the
maximum 0 dBFS (digital clipping level) with an
additional LED to represent overload (O/L). Exceeding
this maximum will result in the A/D clipping the signal,
which may cause audible and unwanted distortion.
Digital Clip LED
A single separate red LED is also included to signify
when a digital clip is occurring.
Input Select
The input Select switch, pressed repeatedly, will step
through the mic, line and digital inputs, with an LED
beside each, which illuminates when that input is
active. A further LED is provided to show when the
transformer has automatically been switched in circuit;
this will change according to the mic-pre replica
selected.
Gain dial
The dial below the input select switch adjusts the level
fed to the A/D. The levels for mic and line are shown
by the outside (mic) and inside (line) arc around the
dial, with the exact numeric value displayed next to
the pre-amp replica name on the front panel LCD
(indicated by ‘Pre-amp Gain dB’).
+48V
Pressing the +48V switch provides +48V phantom
power, suitable for condenser microphones, to the
rear panel XLR microphone connector. This switch
does not affect the other inputs.
If you are unsure whether your microphone requires
phantom power, refer to its handbook, as it is possible
to damage some microphones (most notably ribbon
microphones) by providing phantom power.
Ø
Pressing Ø inverts the phase of the selected input,
primarily used to correct phase problems when using
multiple microphones on a single source.
This switches an analogue, pre-A/D high-pass filter
into the signal path, in order to roll off low
frequencies. This is switchable (in the Setup menu)
between a 75 Hz and 120 Hz roll-off. See page 9 for
more information about the Setup menu. The roll-off
is 12 dB per octave, 6 dB down at 75 or 120 Hz.
Session Saver
Next to the Mic-Pre and A/D section and above the
Clock Select switch is the Session Saver switch. Press
this switch once to arm the Session Saver. Once this
circuit is armed (indicated by the corresponding LED)
a gain reduction will occur if the signal starts to clip.
This is a way of protecting your session from continual
overload if the level is consistently ‘hot’.
The Session Saver’s action is different from a limiter’s
action, as the signal isn’t compressed in any way, just
turned down by an appropriate amount to avoid
overloading. The feature monitors the signal at the
input and output. If the input is overloading, the micpre gain is reduced. If the output is clipped but the
input is clean, the level of the makeup gain is lowered.
When the section has reduced the gain, the Activated
LED will illuminate. Once the level is decreased, it
remains activated until the switch is pressed to disarm
the Session Saver. Pressing once more will then rearm the Session Saver.
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Clock Select and Synchronisation
Clock Select
This switch changes the clock to the sample rate value
indicated by the corresponding LED: 44.1 kHz, 48
kHz, 88.2 kHz, 96 kHz, 176.4 kHz or 192 kHz. If using
an external digital input, the sample rate must be set
to match that of the digital signal fed to the input.
Ext
This switch allows The Liquid Channel™ to
synchronise to an external source, either the
Wordclock or AES input on the rear panel, each
shown by an LED. When a lock is achieved, the
corresponding LED will illuminate. If the LED flashes
the unit is not locked and jitter will be evident.
N.B. If either Wordclock or AES are selected and
there is no cable connected to the relevant input, The
Liquid Channel™ will not achieve lock.
When processing in 176.4 or 192 kHz, The Liquid
Channel can accept and regenerate either 88.2/176.4
kHz or 96/192kHz respectively, depending on the
clock source and destination requirements. See the
Setup menu section on page 9 for more details.
Main LCD and Controls
Pre-amp Gain DB
This area of the display shows the gain (as set using
the Gain control in the Mic-Pre and A/D section) in
dB.
Program Name
This area of the display shows the name of the
currently loaded program memory. Naming and saving
of programs are separate commands; it is advisable to
name the program first, then save it.
Number
This area of the display shows the number of the
currently loaded program memory, from 00-100.
Selecting ‘00’ allows the user to return to the factory
default program memory, which always loads the
‘FLAT trfmr’ mic-pre and ‘FLAT comp’ compressor.
Unlike program memories 01-100, program memory
00 cannot be overwritten.
Pre-amp and Compressor Select
When beginning a session for the first time, it is
recommended to load default program 00 (see above),
as this is an ideal starting point.
Pressing the Pre-amp Select switch causes its LED to
flash. Rotating the DATA wheel then allows a
microphone pre-amp replica (shown in the top left
hand corner of the display window) to be selected by
scrolling through a bank of pre-amp replicas. When
the desired pre-amp is found, press the DATA wheel
once to load the required pre-amp replica.
N.B. To use The Liquid Channel™ as a standalone
compressor with an analogue input, select the Line
input, which will automatically select the transparent
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‘FLAT trfmr’ (transformer) input stage. To use The
Liquid Channel™ as a standalone compressor with a
digital input, you can select the ‘FLAT dig’l’ pre-amp
on the front panel.
Pressing the Compressor Select switch causes its LED
to flash. Rotating the DATA wheel then allows a
compressor replica (shown in the top right hand
corner of the display window) to be selected by
scrolling through the bank of compressor replicas.
When the desired compressor is found, press the
DATA wheel once to load the required compressor
replica.
N.B. Loading a new mic-pre or compressor will not
affect any values dialled in on the front panel. For
example, if the user changes a compressor’s threshold
value from –7 dB to –9 dB and then loads a new
compressor replica as above, that new compressor
replica’s threshold value will initially be –9 dB. (If ‘As
Original Model’ is selected in the Setup menu (see
page 9) the value will reset to the nearest available
value.) To save all edited values when you have
finished editing so that they may be recalled later, use
the Save switch (see page 8).
Harmonics
The dial directly below the pre-amp name allows
desirable harmonic distortion, perceived as ‘warmth’,
to be applied. The exact amount of 2nd-, 3rd-and 5thorder harmonics depends both on the type of preamp chosen and the amount of mic-pre gain. This is
because the amount of each harmonic with respect to
each other is different for pre-amps with valves
compared to those with transformers; and also
because the balance of harmonics changes with level.
This means that a higher gain at the mic-pre stage will
result in a greater, and hence more noticeable, effect
as the harmonics setting is increased. Special ‘hot’
replicas, which can be downloaded from
www
.focusrite.com, provide greater levels of harmonics
application, for those wanting to achieve a seriously
overdriven sound.
The harmonics control allows replication of the subtle
variations between analogue devices, (sometimes two
units of the same type can have different amounts of
harmonic distortion), and allows the user to create an
‘overdriven’ sound without having to overdrive the
pre-amp. Careful use of the Harmonics control will
thus allow the user to ‘tune in’ The Liquid Channel™
replicas to their own individual vintage unit.
The amount of harmonic distortion is indicated by the
LEDs surrounding the dial and a value from 0-15
shown above it. ‘+ODD’ appears next to the value
when third and fifth order harmonics are present.
Compressor Settings
N.B. If the Compressor Controls option in the Setup
menu has been set to ‘As Original Model’, then
depending on the compressor replica selected, not all
of the following settings may be available. With ‘As
Original Model’ selected, only those controls that
were present on the original unit are available for
editing, all other dials display ‘FIXED’ and are inactive.
Similarly, if the dials’ values are reversed on the
original or they have some special operational
features, then these are also replicated on the front
panel. See page 9 for more information on the Setup
menu.
Comp In
The compressor is activated by pressing the Comp In
switch, located in the bottom right corner of the
middle section.
Threshold
The Threshold control sets the level at which
compression begins. The lower the threshold, the
more the signal is compressed. Setting a higher
threshold allows quieter passages in the music or
speech to remain unaffected; only passages that
exceed the threshold will be compressed. The level of
threshold varies depending on the chosen
compressor, and the exact value is shown in dB
directly above the dial on the display window.
Ratio
The Ratio control determines the amount of
compression applied to the signal with increasing
input, and is the ratio of change in input level
compared to change in output level. Higher ratio
settings will produce more noticeable compression, so
for the least obtrusive result, the ratio should be set
at the minimum necessary for the application. For
example, using low threshold and low ratio will
produce a less subjectively noticeable effect than a
high threshold and high ratio, even though the total
amount of compression may be the same. The range
of ratios selectable varies depending on the chosen
compressor replica, and the exact value is shown
directly above on the display window.
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Attack
The Attack control determines how quickly
compression is applied once the level of the source
signal has risen above the threshold. When turned
anti-clockwise the response is very fast, which tends
to make the compressor react to the peak levels of
the signal. This is sometimes desirable, but short
transients can cause unwanted ‘pumping’ of steadier
low-level signals. A slower attack will cause the
compressor to ignore short transients and respond
more to the average loudness of the signal; however
this may seem to increase the relative volume of the
transients. The range of attack times selectable varies
depending on the chosen compressor, and the exact
value is shown in milliseconds (mS) directly above on
the display window.
Release
The Release control determines how quickly
compression is removed once the level of the source
signal has fallen below the threshold. When in the
anti-clockwise position, the compression releases very
quickly, which may be appropriate on rapidly varying
signals to avoid compressing the beats that follow, but
can result in excessive distortion on more sustained
material. Clockwise rotation increases the release
time, giving a smoother effect, but may also result in
transients causing audible ‘pumping’. The Release time
varies depending on the chosen compressor, and the
exact value is shown in milliseconds (mS) directly
above on the display window.
Makeup
Compression results in an overall reduction in level.
The Makeup control allows you to increase the gain of
the compressed signal. The range of makeup values
selectable varies depending on the chosen
compressor, and the exact value is shown in dB
directly above on the display window.
Stereo Link
This switch enables Liquid Channel™ units to be
linked, so that the ‘master’ can control multiple ‘slave’
units. To set whether the unit is the ‘master’ or ‘slave’,
the Setup menu must be accessed. See page 9 for
more information on the Setup menu, and page 10 for
more information on linking multiple units.
Gain Reduction bar graph
The vertical LED meter indicates the action (Gain
Reduction) of the compressor, in expanding
increments down to –15 dB.
3-Band EQ
The Liquid Channel™ features a new digital
(‘modelled’ rather than ‘convolved’) EQ, loosely based
on the classic Focusrite sound of the original ISA 110.
This is designed to allow small amounts of corrective
shaping. All of the EQ settings can be saved, along with
those of the mic-pre and compressor, in one of the
Program slots (see the DATA SELECT section below).
EQ In
Located in the bottom right corner of the section, this
switch activates the EQ section and is illuminated
when the EQ is active.
Pre Comp
Pressing this switch (illuminated when active) allows
the EQ to be moved to a position prior to the
compressor in the signal path.
Show Value
Pressing this switch (illuminated when active) causes
the exact values of each EQ dial to be shown in the
display window, for more visual accurate parameter
modification.
High-frequency shelving
The two upper dials control the frequency (left dial)
and gain (right dial) of the high-frequency shelf. The
frequency varies from 200 Hz to 20 kHz, and the gain
between –18 dB and +18 dB.
Low-frequency shelving
The two lower dials control the frequency (left dial)
and gain (right dial) of the high-frequency shelf. The
frequency varies from 10 Hz to 1 kHz, and the gain
between –18 dB and +18 dB.
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