Focusrite Liquid Channel™ User Manual

Introduction

Thank you for choosing the Liquid Channel™, created by the Focusrite team. We hope this device will meet your expectations and provide productive recording experiences for years to come. For feedback on your recordings, please contact us via email at sales@focusrite.com.

Important Safety Instructions

Read these instructions and keep them for future reference. Also, follow all instructions and warnings on the unit.

• Do not block ventilation openings on the rear panel. Do not insert objects into the openings. Ensure adequate ventilation at all times.
• Do not use a damaged or worn power cord.
• Disconnect the unit from the mains before cleaning. Use only a soft, damp cloth. Do not spray any liquid onto the unit.
• Disconnect the unit and refer servicing to qualified personnel if: the power plug or cord is damaged, liquid has entered the unit, the unit has been dropped or the chassis is damaged, the unit is not operating correctly or shows impaired performance. Do not adjust any controls not described in this manual.
• Observe the safety and usage instructions for the provided plugs. A polarized plug has two pins, one wider than the other. A grounding plug has two pins and a grounding terminal. These are for your safety. If the provided plug does not fit your wall socket, consult an electrician to replace it.
• This unit operates at the voltages indicated on the rear panel. Ensure voltage settings and fuses are correctly set before connecting to the mains. Do not change mains voltage settings while the unit is connected.
• To prevent fire hazard, replace fuses with identical types (see rear panel indications).
• The power section contains no user-serviceable parts. Contact your Focusrite dealer for assistance from qualified personnel.

Mains Connections

An AC power cord is supplied with the unit, with a plug appropriate for your country.

For units supplied to the USA, Canada, Taiwan, and Japan:

• Phase: Black
• Neutral: White
• Ground: Green

For units supplied to other countries:

• Phase: Brown
• Neutral: Blue
• Ground: Green and Yellow

Architecture of the Liquid Channel™

The Liquid Channel™ is fundamentally different from previous Focusrite products and indeed any other dynamics processor available today. While it is extremely simple to use, please take time to read this section, which provides an overview of the signal path and storage capabilities.

Presentation

The Liquid Channel™ is the first implementation of Focusrite's innovative "Liquid Technology" concept. It brings classic processing with all its front-panel settings into the digital age, eliminating the need for tedious patching and offering enhanced fluidity and reliability for studio environments. Essentially, the Liquid Channel™ can be configured to behave like any historical preamp, compressor, or a combination of both, all within a 2U, 192kHz unit.

This is achieved through a two-part process. Firstly, Dynamic Convolution techniques are employed using high-speed SHARC chips that apply level-dependent impulse responses to each audio sample. While this is sufficient to identically reproduce a compressor's sonic behavior, it is different for a classic preamp, whose subtle behavioral nuances rely on interaction with a specific microphone. The Liquid Channel™ addresses this with an advanced analog interface. The preamp can change its impedance and modify the signal path, either through an electronic circuit or a transformer. This allows for a perfect replica of the original interaction characteristics while remaining transparent in the signal path.

The Liquid Channel™ can thus perform a high-quality replica of the sonic character of any classic preamp and compressor. With fully digital front-panel controls, all parameters can be saved into one of 100 memories, allowing session settings to be recalled with a single button press. A new, fully integrated equalizer provides a complete "Liquid Technology" pathway.

A rear-panel USB port provides a link to the LiquidControl™ software, enabling archiving of replicas and user programs, as well as remote control of the unit. The Liquid Channel™ ships with 40 classic preamp replicas and an equal number of historical compressor replicas, but its capacity is virtually unlimited, as the USB port allows downloading the latest replicas from the dedicated site: focusrite.com/liquid.

Finally, to account for variations in second, third, and fifth-order harmonic distortion (generally considered to contribute to "warmth") found between different preamps, a control is provided. This essential feature will appeal to users of "vintage" products, offering total control over the entire sonic palette.

Capacities

The Liquid Channel™ comes with 40 preamp and 40 compressor replicas. The LiquidControl™ software offers free access to additional replicas from the dedicated site focusrite.com/liquid, which can be downloaded to the Liquid Channel™ via the USB port.

Memories

The Liquid Channel™ features 100 memories for saving your preferred preamp/compressor/EQ combinations. These memories can be saved, archived, and loaded from an external computer using the USB port and LiquidControl™ software. All parameters are saved, allowing for total recall, including mic gain. Using LiquidControl™, an almost unlimited number of replicas and programs can be stored on your PC or Mac and loaded into the Liquid Channel™ as needed. You can also email your favorite programs to other users worldwide for absolute recall.

Signal Path

The Liquid Channel™ has both analog (mic and line) and digital (AES-EBU) inputs, and analog (line) and digital (AES-EBU) outputs.

Analog signals connected to the mic input are routed to an analog mic preamplifier stage before passing through an A/D converter to access the preamp's digital convolution section. The specific sonic characteristics of the selected preamp replica are then applied to the signal. This signal then passes through the compressor and equalizer sections (in that order, unless the "Pre Comp" switch is engaged – see page 30 for details). The processed signal is finally directed to the digital output, or via the D/A converter, to the analog output.

Analog signals connected to the line input follow the path described above but bypass the initial mic preamp stage and access the A/D converter directly. The selected preamp type is "FLAT trfmr" (transformer) when the front-panel input selector is set to LINE. Digital signals connected to the digital input are routed directly to the preamp's digital convolution section. However, this path can be modified (see "Preamp and Compressor Selection" on page 28 for details).

Rear Panel Connections

XLR Audio Inputs and Outputs: All 3-pin XLR connectors (Mic Input, Line Input, Line Output, from left to right) are wired as follows:

• Pin 1: Shield/Chassis
• Pin 2: Audio Hot (0°)
• Pin 3: Audio Cold (180°)

AES Inputs and Outputs: The AES input and output connectors provide digital inputs and outputs in AES-EBU format. See pages 33-38 for details on interconnections and capabilities.

Clock Input and Output: The WORDCLOCK IN BNC connector allows the Liquid Channel™ to be linked to an external clock source. The WORDCLOCK OUT BNC connector allows the Liquid Channel™ to provide a clock to external equipment. See page 33 for more details on synchronizing the Liquid Channel™ with an external clock source.

Digital Link Bus: The DIGITAL LINK BUS connectors allow chaining 2 or more units for stereo or multi-channel operation, where one unit (the master unit) controls the settings of the other units. Additionally, when multiple units are used digitally and in stereo, the digital audio signal passes through this digital link bus. Both connectors are RCA (phono) connectors. See page 33 for more details on chaining multiple units.

USB: The USB connector allows the Liquid Channel™ to be connected to a computer running the LiquidControl™ software. This enables remote control, loading, and archiving. For more information, consult the separate manual for the LiquidControl™ software, downloadable from focusrite.com/liquid. For remote control up to 45m, contact Focusrite for information on a USB-CAT5 (Ethernet) converter.

Front Panel Controls

Digital Controls: These controls are all tactile rotary encoders. They rotate indefinitely, and their value is indicated (except for the DATA wheel) by LEDs around their circumference. The exact numerical value can be read on the screen in the center of the front panel. As all controls are digital, settings can be easily saved and recalled, and edited using the LiquidControl™ software (for details, consult the separate LiquidControl™ software manual, downloadable from focusrite.com/liquid). Note: The internal memory stores settings made on the front panel that are left unchanged for over 10 seconds. These settings are then recalled upon the next power-up.

Power: Powers the unit on. Power on the Liquid Channel™ before any other equipment connected to its outputs.

Mic Preamp and A/D Converter:

• Level Display: A single vertical LED bar graph with peak hold indicates the signal level at the output of the mic preamp to the A/D converter, adjustable by the gain control in the mic preamp section. The scale ranges from -20dBFS up to a maximum of 0dBFS (digital saturation level), with an additional LED indicating overload (O/L). Exceeding this level results in A/D converter saturation and consequently audible, undesirable distortion.
• Digital Saturation LED: A red saturation LED is also present to signal when digital saturation is occurring.
• Input Selection: The input selection switch operates in a loop: mic, line, digital inputs. An LED lights up to indicate the selected source. An additional LED indicates that the transformer has been automatically switched into the circuit; this changes depending on the chosen replica type.
• Gain Control: Located below the input selector, this control adjusts the send level to the A/D converter. The available range is indicated by the peripheral markings: the outer ring is for microphone, the inner for line source. LEDs around the circumference show the level. The exact value is readable on the screen, to the right of the chosen preamp replica name (under the "Preamp Gain dB" marking).
• +48V: This switch engages 48V phantom power for condenser microphones, available on the mic XLR connector. Other inputs are not affected. If you are unsure whether your microphone requires phantom power, consult its manual, as some types (especially ribbon mics) may be damaged.

Front Panel Operations

Phase Invert (Ø): The Ø switch inverts the phase of the selected input. This is generally used to correct phase problems when multiple microphones capture the same sound source.

Low-Pass Filter (=): This switch engages a low-pass filter before A/D conversion to attenuate low frequencies. The cutoff frequency is switchable (in the Setup menu) to 75Hz or 120Hz. See page 32 for Setup menu details. The slope is 12dB/octave, with the -6dB point centered at 75Hz or 120Hz.

Session Saver: To the right of the input and A/D conversion section, and above the clock selector, is the session saver button. Pressing this button once activates the session saver, lighting the adjacent "armed" LED. Once activated, a gain reduction will appear if the signal begins to saturate; this protects your session from continuous overload if the signal is consistently too high.

The session saver operates differently from a limiter, as the signal is not compressed but attenuated appropriately. This function monitors the signal level at both input and output. If the input saturates, the preamp gain is reduced. If the output saturates but the input is "clean", the gain reduction level is lowered. The "activated" LED lights up when the circuit reduces gain. Once gain is reduced, the circuit remains active until you press the button a second time to deactivate it, and the "armed" LED turns off. Pressing it again will reactivate the process.

Clock Selection & Synchronization:

• Clock Select: This pushbutton adjusts the clock to the sample rate indicated by the adjacent LEDs: 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz, or 192kHz. If using a digital input, the selected sample rate must match that of the digital signal input.
• Ext: This switch allows the Liquid Channel™ to synchronize with an external source, either the WORDCLOCK IN or AES IN on the rear panel, each indicated by an adjacent LED. The "lock" LED indicates effective synchronization. If this LED blinks, the unit is not synchronized, and jitter phenomena will be evident.
• NOTE: If the clock or AES source is selected indiscriminately and no cable is connected to the relevant input, the Liquid Channel™ will not synchronize.
• At 176.4kHz or 192kHz, the Liquid Channel™ can accept and regenerate 88.2/174.4kHz or 96/192kHz, respectively, depending on the clock source and the needs of connected equipment. See pages 32 and 33 for more details.

Screen and Main Settings

Pre-amp Gain dB: This area of the screen displays the gain value in dB, as set by the gain control knob in the Mic Preamp and Converter section.

Program Name: This area of the screen displays the name of the program currently loaded into memory. Naming and saving are separate functions. It is recommended to name the program first, then save it.

Number: This area of the screen displays the number of the program currently loaded into memory, ranging from 00 to 100. Selecting "00" allows the user to load the factory default program, where the "FLAT trfmr" preamp and "FLAT comp" compressor are loaded. Unlike all other programs, this one cannot be erased.

Preamp & Compressor Selection: When starting a new session, it is recommended to load the default program "00" as an ideal starting point.

• Press the "Preamp select" pushbutton; it will flash. Then, turn the DATA wheel to select a preamp replica from the resident bank. The corresponding name will be displayed in the top-left corner of the screen. Once the desired replica is accessed, press the DATA wheel to validate your choice and load it into memory.
• Note: To use the Liquid Channel™ as a compressor-only unit with analog input, select the line input, which automatically selects a transparent transformer preamp ("FLAT trfmr").
• To use the Liquid Channel™ as a compressor-only unit with digital input, you can select the "FLAT dig'1" position on the front panel.
• Press the "Compressor select" pushbutton; it will flash. Then, turn the DATA wheel to select a compressor replica from the resident bank. The corresponding name will be displayed in the top-right corner of the screen. Once the desired replica is accessed, press the DATA wheel to validate your choice and load it into memory.
• Note: Loading a new preamp or compressor does not alter existing settings displayed on the screen. For example, if you change the compressor threshold from -7dB to -9dB and then load a new compressor, its threshold value will be -9dB (if the "As Original Model" function was selected in the Setup menu (see page 32), the value will reset to the closest available value). To save all settings and recall them later, use the "Save" pushbutton (see page 32).

Harmonics: This setting, located below the current preamp name, allows you to apply a certain amount of harmonic distortion, generally considered to contribute to "warmth". The exact quantity of second, third, and fifth-order harmonics depends on both the selected preamp type and the input gain setting. This is because the relative quantity of each harmonic varies depending on whether the preamp uses a transformer or not, and the balance between harmonics changes with signal level. This means that the higher the preamp gain, the more significant and audible the harmonic contribution becomes, increasing with the harmonics setting. Specific replicas with higher harmonic distortion are available at focusrite.com/liquid for sounds requiring heavy saturation.

The harmonics setting allows you to replicate the subtle variations found between two analog units (sometimes, two units of the same model may exhibit different harmonic distortion levels). It also offers the possibility of a "saturated" sound without actually saturating the preamplifier. Meticulous adjustment can also "tune" a chosen replica in the Liquid Channel™ to match an original model in your studio, enhancing the harmony of colors between units.

The quantity of harmonics is indicated by LEDs around the control, and a value between 00 and 99 is displayed on the screen above. The message "+ODD" following the value indicates the presence of third and fifth-order harmonics.

Compressor Settings

Note: If the "As original Model" option is selected in the Setup menu, available settings will depend on the chosen replica type; some settings may not be valid. With "As Original Model", only settings present on the original model are available. All other settings will display "FIXED" and be inactive. Similarly, obtainable values and specific functions for the chosen replica are accessible on the front panel. See page 32 for Setup menu details.

Comp In: The compressor is activated by pressing the "Comp In" pushbutton, located in the bottom-right corner of the central section.

Threshold: The threshold setting adjusts the level at which compression begins. The lower the threshold, the more the signal is compressed. Setting a higher threshold leaves quieter passages untouched, compressing only those exceeding the threshold. The threshold level depends on the chosen replica type. The exact dB value is shown on the screen, just above the setting.

Ratio: The ratio setting determines the amount of compression applied to the signal once it has crossed the chosen threshold. It is the ratio between the change in input level and the change in output level. Higher ratios produce more audible compression. For a subtler result, adjust the ratio to the minimum required for the application. For example, with a low threshold and low ratio, the effect will be subjectively less noticeable than with a high threshold and high ratio, even if the compression amount is nearly identical. The range of available ratios depends on the chosen replica type. The exact value is displayed on the screen, just above the setting.

Attack: The attack time setting determines the speed at which compression is applied to the signal as soon as it crosses the threshold. Rotating counter-clockwise provides a very fast response, tending to make the compressor react to signal peaks. While sometimes desired, very brief transients can cause a "pumping" effect on quieter, longer signals. A slower attack time causes the compressor to ignore brief transients and respond more to the signal's average level. However, this gives the impression of a more significant relative level for transients. The range of available attack times depends on the chosen replica type. The exact value is displayed on the screen, just above the setting.

Release: The release time setting determines how long it takes for the compressor to stop acting on the signal once it has dropped below the threshold. Rotating counter-clockwise provides a very fast release. This can be appropriate for rapidly changing signals to avoid compressing the signal when its level suddenly drops, but can cause excessive distortion on signals with a more sustained level. Clockwise rotation results in a longer release time for a less radical effect, but can cause transients to produce an audible "pumping" effect. The range of available release times depends on the chosen replica type. The exact value is displayed on the screen, just above the setting.

Makeup: Compression typically results in an overall level reduction. This control allows you to increase the gain of the compressed signal. The available gain range depends on the chosen replica type. The exact value is displayed on the screen, just above the setting.

Stereo Link: This switch allows chaining multiple Liquid Channel™ units, enabling one "master" unit to control multiple "slave" units. To choose the unit's state (master or slave), you must access the Setup menu. See page 32 for Setup menu information and page 33 for chaining multiple units.

Gain Reduction Meter: This vertical LED meter shows the compressor's action (gain reduction) in increments starting from -15dB.

3-Band Equalizer

The Liquid Channel™ features a new digital equalizer (modeling rather than convolution-based), designed using the specific sonic character of the Focusrite ISA 110 model. This equalizer is intended for signal tone shaping. All settings can be saved with the preamp and compressor settings in one of the available memories (see the DATA SELECTION section below).

• EQ In: Located in the bottom-right corner of this section, this switch activates the equalization section and lights up to indicate it is active.
• Pre Comp: Pressing this pushbutton (which lights up) allows you to place the equalizer before the compressor in the signal path.
• Show Value: Pressing this button (which lights up) displays the exact equalization values on the central screen, providing more precise visual information about the settings.
• Treble Shelving EQ: The two rotary controls at the top of the equalization section allow adjustment of frequency (left knob) and gain (right knob) for the treble spectrum. Frequency is variable from 200Hz to 20kHz, and gain is adjustable between -18dB and +18dB.
• Bass Shelving EQ: The two rotary controls at the bottom of the equalization section allow adjustment of frequency (left knob) and gain (right knob) for the bass spectrum. Frequency is variable from 10Hz to 1kHz, and gain is adjustable between -18dB and +18dB.
• Mid Parametric Band: The two rotary controls in the middle of the equalization section allow adjustment of frequency (left knob) and gain (right knob) for the mid spectrum. Frequency is variable from 100Hz to 10kHz, and gain is adjustable between -18dB and +18dB.
• Hi Q: This switch (illuminated when active) engages a higher Q factor for the mid parametric equalizer, affecting a narrower band. When inactive, the Q factor is 0.8. When active, the Q factor becomes 2.5.
• Sidechain EQ: This switch (illuminated when active) assigns the equalization section to the compressor's sidechain for frequency-dependent compression, useful for compressing specific parts of the signal spectrum, such as a de-esser.
• Sidechain Listen: This pushbutton (illuminated when active) allows for monitoring the sidechain. This function provides easy adjustment of frequency settings for frequency-selective compression. Release the pushbutton once the adjustment is complete.

Compression & EQ Settings

• Bypass: This switch (illuminated when active) bypasses the compression and equalization sections, creating a direct link to the output.
• Compare: This switch allows you to temporarily revert to the base settings of the chosen program for comparison with your current settings. Pressing once recalls the original settings; pressing a second time returns to the current settings.
• Revert: After performing a comparison as described above, if you prefer the original settings, pressing this button allows you to return to the last saved settings. Note: All modifications made to the saved program will be lost. Phantom power and clock settings are not saved in programs.

Data Selection

This section manages data: saving, labeling, and recalling sessions.

• DATA Wheel: Rotating this wheel allows selection of a preamp or compressor replica (if either the Preamp Select or Compressor select switch has been activated). It also allows selection or modification of parameters within the DATA SELECT section. Press the rotary encoder once to validate a selection.
• Save: Pressing this button allows saving the current session (all front-panel parameters) into one of the available memories. The button flashes upon the first press. The DATA wheel then allows you to scroll through the 100 available memories. Once the desired location is chosen (which can be an existing or empty memory), pressing the DATA wheel saves the settings. To cancel the operation, press the SAVE button again (without pressing the DATA wheel). When a parameter has been modified in a saved program, an asterisk appears next to the program number, indicating that the program has been edited and may require saving. Note: If you overwrite an existing memory, its content will be lost.
• If you run out of memory slots, the LiquidControl™ software allows you to save an unlimited number of programs to your PC or Mac computer and load them into your Liquid Channel™ whenever desired. Refer to the LiquidControl™ documentation for details.
• Recall: This switch loads a memory, recalling all parameters for a specific session. Once the "Recall" pushbutton is pressed, it flashes, and the DATA wheel can be turned to navigate through all available memories. Once the desired program is selected, press the DATA wheel to validate your choice. To cancel the operation, press the RECALL button again (without pressing the DATA wheel). Phantom power and clock settings are not saved in programs.
• Name: This switch allows you to assign a name to a program. Once this pushbutton is pressed, it flashes, and the DATA wheel allows you to enter characters one by one. Turn the DATA wheel to display the desired letter, then press DATA to move to the next letter, and so on. Once the program name is entered, the program itself must be saved (unless it has already been done): see the saving procedure above.
• Clear: While in naming mode, this pushbutton allows you to erase all characters, enabling you to start over. This function has no effect on other parameters.

Setup Configuration

This menu allows you to configure the Liquid Channel™. The DATA wheel allows navigation through the various options. Pressing the DATA wheel saves the chosen parameter and moves to the next. Press the "Setup" pushbutton once to exit. The Setup menu options are as follows:

• Low-Pass Filter: Use the DATA wheel to select a cutoff frequency of 75Hz or 120Hz for the low-pass filter. See the Mic Preamp and A/D Converter section on page 26 for details.
• Compression Settings: This option allows you to choose whether available settings are limited to those present in the original model whose replica you have chosen, or not. Select "Original Model" or "FREE". The "FREE" option gives you access to settings not available on the original unit.
• Clock Input: When the unit uses a digital input at 176.4 or 192kHz and the EXT sync switch is set to Clock Input, the unit can lock to 88.2/174.4kHz or 96/192kHz, respectively, depending on the clock source.
• Clock Output: When the unit uses a digital input at 176.4 or 192kHz, the unit's Clock Output can be adjusted to regenerate 88.2/176.4kHz or 96/192kHz, respectively, depending on the clock destination.
• "Digital Link Buss" Chaining: If you use more than one Liquid Channel™, this option specifies the number of chained machines. Up to eight Liquid Channel™ units can be chained using the digital link buss connectors. Consult page 33 for more information. If only one unit is used, ensure the option is set to "OFF".
• Gain Linkage: If digital chaining has been specified for more than one unit (see above), this parameter specifies the machine's state: master or slave. For more than two chained units, this parameter assigns a number to each machine, and each machine must have its own identification number, ranging from 2 to 8. The available values are 1 for the master machine and 2 to 8 for the slave machines. Note: This option is only available when the preceding parameter has been set to a value other than "OFF".
• Slave Controls to Master: If the Liquid Channel™ is designated as a slave to another master Liquid Channel™ unit, this option appears. You can choose "Yes" or "No". Choosing "Yes" makes all settings of the slave unit dependent on the master unit's settings (the slave unit's settings are then inactive). In this case, if a new program is recalled on the master unit, the slave unit will follow. This corresponds to the standard usage in most chaining scenarios. Choosing "No" allows you to modify settings on the slave unit independently, even if the gain reductions of the master and slave units are chained. Choosing "No" allows for independent adjustment, for example, a different preamp gain or compressor ratio between the master and slave units.
• AES Chaining: If the "Digital Link Buss" parameter is not set to "OFF", an AES chaining option appears in the Setup menu. This option allows multiple Liquid Channel™ units to be used as grouped AES pairs, sending the signals from both machines via a single cable (as shown in Figure 5, page 35). There are three possibilities:
  • Both units receive an analog signal, and the master unit sends AES - Set the master unit: "set master link AES-Right: from slave" and set the slave unit: "Link AES-Right: output".
  • Both units receive an analog signal, and the slave unit sends AES - Set the master unit: "link AES-Right: to slave" and set the slave unit: "Link to master AES-Right: input".
  • The master unit receives and sends AES - Set the master unit: "Link AES-Right: to and from slave" and set the slave unit: "Link to master AES-Right: in and out".
• USB ID: This parameter allows you to assign a different USB identification number to each machine. When the LiquidControl™ software needs to manage multiple Liquid Channel™ units, each unit must have its own identification number, ranging from 1 to 8, to be accessed by the LiquidControl™ software. Turn the DATA wheel to modify the address and validate by pressing the DATA wheel. Refer to the downloadable LiquidControl™ documentation for more information.

Chaining Multiple Units

Using the digital link buss connectors, up to 8 Liquid Channel™ units can be chained, with one master unit controlling the compressor, preamp gain, and other settings of the slave machines. This means you can use multiple Liquid Channel™ units in stereo or multi-channel operation, with perfect tracking between machines.

The procedure for chaining multiple machines is as follows:

1. Use an RCA-RCA cable between the master unit's DIGITAL LINK BUS output and the first slave machine's DIGITAL LINK BUS input. When chaining multiple units, connect the first slave machine's output to the second slave machine's input, and so on for all chained machines.
2. Using an RCA-RCA cable, connect the last slave machine's DIGITAL LINK BUS output to the master machine's DIGITAL LINK BUS input. See the diagram on page 38.
3. In the Setup menu, access the "Compressor Gain Linkage" option (see previous page) to specify the number of chained machines. Do the same for all machines in the chain.
4. In the Setup menu, access the "Gain Linkage" option and assign number 1 to the master machine (see page 38). Assign number 2 to the first slave machine, number 3 to the second slave machine, and so on for each machine in the chain.
5. If all slave units are to be controlled by the master unit, ensure that on all slave units, the "Link slave controls to master" setting in the Setup menu is positioned to "YES".
6. Ensure that the preamp and compressor replicas are loaded. If necessary, use the LiquidControl™ software for this. Refer to the downloadable LiquidControl™ documentation for more information.
7. If you wish to use two Liquid Channel™ units for stereo digital input and output at a 44.1, 48, or 96kHz sample rate, a stereo AES/EBU signal can be provided via a single AES connection (even though each Liquid Channel™ is a mono unit). To send a stereo digital audio signal, connect a suitable cable to the first Liquid Channel™'s AES digital input. Use an RCA-RCA cable to connect the first Liquid Channel™'s DIGITAL LINK BUS output to the second unit's DIGITAL LINK BUS input. Use another RCA-RCA cable to connect the second Liquid Channel™'s DIGITAL LINK BUS output to the first unit's DIGITAL LINK BUS input. Finally, use another AES cable on the second Liquid Channel™'s AES digital output to send the stereo digital signal to the destination device. Refer to Diagram 9 on page 38 (Stereo digital inputs/outputs for digital insertion, 44.1-96 kHz) for more details. Note: If you wish to use more than two Liquid Channel™ units in stereo AES pairs, they cannot all be connected in this manner. Refer to Figure 6 on page 36. The AES chaining option in the Setup menu must be adjusted appropriately (see page 32).
8. If you are using the LiquidControl™ software, ensure you assign a USB identification number to each unit using the "USB ID" option in the Setup menu. We recommend assigning a USB ID that is consistent with the numbering in the "Gain Linkage" parameter: for example, SLAVE machine #2 should have USB ID 2, etc.

Connections and Applications

Diagram 1: All Analog Connection. A microphone is connected via XLR to the MIC INPUT of the Focusrite Liquid Channel™. The LINE OUTPUT is connected via XLR to an external device.

Diagram 2: Digital Output, Liquid Channel™ is Master Clock. A microphone is connected via XLR to the MIC INPUT of the Focusrite Liquid Channel™. The AES OUTPUT is connected via AES to the DAW INTERFACE's AES INPUT.

Diagram 3: Digital Output, Liquid Channel™ is Wordclock Slave. A microphone is connected via XLR to the MIC INPUT of the Focusrite Liquid Channel™. The AES OUTPUT is connected via AES to the DAW INTERFACE's AES INPUT. The Liquid Channel™'s WORDCLOCK OUT is connected to the WORDCLOCK INPUT of the DAW INTERFACE.

Diagram 4: Digital Output, Liquid Channel™ is AES Slave. A microphone is connected via XLR to the MIC INPUT of the Focusrite Liquid Channel™. The AES OUTPUT is connected via AES to the DAW INTERFACE's AES INPUT. The Liquid Channel™ receives the clock signal via the AES connection.

Diagram 5: Stereo Operation, 44.1-96 kHz, Liquid Channel™ is Wordclock Slave. Two Liquid Channel™ units are shown, one labeled MASTER and one SLAVE. A microphone is connected to the MIC INPUT of each unit. The MASTER unit's WORDCLOCK OUT is connected to the SLAVE unit's WORDCLOCK INPUT. The MASTER unit's DIGITAL LINK BUS OUT is connected to the SLAVE unit's DIGITAL LINK BUS IN. The SLAVE unit's AES OUTPUT is connected to the DAW INTERFACE's AES INPUT. (See "Chaining Multiple Units" page 33).

Diagram 6: 4-Channel Operation, 44.1-96 kHz, Liquid Channel™ is Wordclock Slave. Four Liquid Channel™ units are shown, two labeled MASTER and two SLAVE. Microphones are connected to each MIC INPUT. Each MASTER unit's WORDCLOCK OUT is connected to its corresponding SLAVE unit's WORDCLOCK INPUT. Each MASTER unit's DIGITAL LINK BUS OUT is connected to its corresponding SLAVE unit's DIGITAL LINK BUS IN. The SLAVE units' AES OUTPUTs are connected to the DAW INTERFACE's AES IN 1 and AES IN 2.

Diagram 7: Stereo Operation, 176.4 kHz/192 kHz, Liquid Channel™ is AES Slave. Two Liquid Channel™ units are shown, one labeled MASTER and one SLAVE. Microphones are connected to each MIC INPUT. The MASTER unit's WORDCLOCK OUT is connected to the SLAVE unit's WORDCLOCK INPUT. The MASTER unit's AES OUTPUT is connected to the SLAVE unit's AES INPUT 1. The SLAVE unit's AES OUTPUT is connected to the DAW INTERFACE's AES INPUT 1. For 176.4 kHz/192 kHz operation, configure the digital workstation for "send/receive" in "dual wire" mode (double cabling). (See "Chaining Multiple Units" page 33).

Diagram 8: Mono Digital Input/Output for Digital Insertion, 44.1-192 kHz. The Liquid Channel™'s AES INPUT is connected to the DAW INTERFACE's AES OUTPUT, and the Liquid Channel™'s AES OUTPUT is connected to the DAW INTERFACE's AES INPUT. For 176.4 kHz/192 kHz operation, configure the digital workstation for "send/receive" in "dual wire" mode (double cabling).

Diagram 9: Stereo Digital Input/Output for Digital Insertion, 44.1-96 kHz. A SLAVE unit and a MASTER unit are shown. Microphones are connected to each MIC INPUT. The SLAVE unit's AES OUTPUT is connected to the MASTER unit's AES INPUT. The MASTER unit's DIGITAL LINK BUS OUT is connected to the DAW INTERFACE's AES IN and AES OUT. (See "Chaining Multiple Units" page 33).

Diagram 10: Stereo Digital Input/Output for Digital Insertion, 176.4 kHz/192 kHz. A SLAVE unit and a MASTER unit are shown. Microphones are connected to each MIC INPUT. The SLAVE unit's AES OUTPUT is connected to the MASTER unit's AES INPUT 1. The MASTER unit's DIGITAL LINK BUS OUT is connected to the DAW INTERFACE's AES IN 1 and AES OUT 1. The SLAVE unit's AES OUTPUT is connected to the DAW INTERFACE's AES IN 2 and AES OUT 2. For 176.4 kHz/192 kHz operation, configure the digital workstation for "send/receive" in "dual wire" mode (double cabling). (See "Chaining Multiple Units" page 33).

Frequently Asked Questions

Q: What type of technology is used in the Liquid Channel™?
A: The technology involves Dynamic Convolution techniques and a new type of preamp which, together, form replicas of historical preamps and compressors.

Q: What is Dynamic Convolution?
A: The convolution process has been defined as: "the term given to the mathematical technique for determining the output of a system, for a given input signal and the system's impulse response." This means that if you know what goes into your system and can control your system's impulse response, you can then define your system's output exactly. In other words, you can create a replica of a compressor's sound, and even a preamplifier's if you add an adapted analog circuit. Put another way, Focusrite has found a way to replicate how a given compressor or preamp influences the sound of a signal.

Q: How is this process different from simulations or modeling already on the market?
A: Modeling involves observing how an appliance works and then generating code to emulate how a particular appliance would respond, generally in a limited number of cases considered as models. Convolution, on the other hand, records data on how an appliance behaves and then creates a replica of it. To use a simple analogy, it's like the difference between sampling and synthesis; if you want your keyboard to generate a REAL violin sound, you sample a violin, and the closer you want the sound to be to the original, the more samples you take at closer intervals; synthesis, on the other hand, generates a waveform resembling that of a violin.

Q: Why have modeling techniques never truly succeeded in accurately reproducing how a compressor or preamp responds?
A: The problem with a compressor is that it's a dynamics processor that reacts to signal changes, and its response varies based on those changes. The problem with a preamplifier is similar – a preamp constantly interacts with the connected microphone, and it is the microphone-preamp combination that characterizes the sound. The dynamic convolution process combined with a specific electronic circuit allows for a replica of these complex interaction phenomena.

Q: What does the impulse response and convolution process involve?
A: Some time ago, Focusrite conducted extensive impulse response analyses on a wide collection of historical preamps, compressors, and equalizers. An impulse signal is generated. This signal, extremely brief in time, contains an unlimited number of frequencies and is sent into the unit to be replicated. By measuring the output signal, Focusrite's R&D department was able to calculate exactly what the unit had done to the signal and then reproduce every aspect in terms of frequency and time: frequency response, dynamic range, distortion, everything! A single impulse, of course, only shows how a unit reacts to a given level. It is therefore necessary to record all information provided with a signal of sufficient amplitude to excite distortion at the input of the unit being measured, then generate a signal with slightly lower amplitude and record all information again, then with even lower amplitude, and so on, gradually reducing the level down to a signal equal to the unit's noise floor. Once all this data is recorded, you can then reproduce any input level change, meaning, reproduce the unit's response to any type of input signal. All that remains is to apply the convolution to all combinations of settings, and you get a replica ready for use.

Q: So, can the Liquid Channel™ reproduce the sound of any compressor or preamp, regardless of type?
A: Yes, and more. Once you have a Liquid Channel™, you can mix and match the sound of your dream preamp and compressor and memorize them to reproduce any combination.

Q: How is it practically possible for a unit to have the processing power required to produce all responses for ALL settings of ALL these preamps AND all these compressors?
A: That's a good question. SHARC chips, the world's fastest, implemented for audio applications, are used to handle such needs. This, along with countless hours patiently spent creating replicas of all these historically significant audio processors.

Q: So, is everything pre-programmed?
A: No, all convolution calculations have been done for you, but the impulse response occurs in real-time within the Liquid Channel™.

Q: Can the Liquid Channel™ replicate my own choice of preamp or compressor?
A: No, the process is highly specialized and remains within Focusrite's R&D. However, the unit comes with 40 preamp and 40 compressor replicas ready for use. You can, however, create your own combinations, with or without equalization, and memorize them.

Q: Are there user memories?
A: Yes, your preamp and compressor combination can be saved into one of the 100 available memories. All parameters, including preamp gain, equalization, and compressor settings, are saved.

Q: What if I want to use a replica of a specific preamp or compressor not in the library?
A: Focusrite plans to continue recreating replicas of other preamps and compressors. These new replicas will be available on the dedicated Liquid Channel™ site, focusrite.com/liquid. The free LiquidControl™ software will allow you to download them using the USB port and a PC or Mac computer. You can also save your memories and/or preamp or compressor replicas to this computer, and even edit them from there. All parameters will be editable on screen, including gain settings, and can be transferred from session to session into a Pro Tools directory, for example.

Q: What if I accidentally overwrite my favorite compressor replica?
A: No problem – you can always reload a backup from your PC or Mac, or download the original programs from focusrite.com/liquid.

Q: How can convolution replicate the interaction between a preamplifier and a microphone?
A: By itself, it cannot. A separate analog circuit must be present and function with the convolution process.

Q: But why is the preamplifier such a problem?
A: Microphone preamplifiers have always been designed to connect with a microphone, but this interactivity system is not 100% effective. Since the 1920s, microphone preamps have been designed to adapt to a wide variety of microphones – carbon dynamic mics, then moving coil models, then tube amps, large diaphragm, phantom-powered condensers, etc. In fact, all types of preamps, "vintage" or more recent, are extremely different from each other in their input circuit design. The wide variety of input circuits, electronic or transformer, that have appeared over the years presents a very wide range of impedances, which is why an analog input circuit is necessary. If a specific microphone model is not loaded by the input circuit in exactly the same way as by the original "vintage" preamp, the sound will be different.

Q: So, there is no standard preamp?
A: Effectively. Take a transformer, for example. It consists of two windings; the first generates a magnetic field that is transmitted to the second winding. This itself is not a fixed mechanical transfer, and there are many variations in a transformer. The load impedance at the preamp input is also always a key factor – when you connect a microphone, it has its own output impedance. Both sides (microphone and preamp) interact, and a variation in frequency response depending on the level is the result. Capacitances also interact, and these values also vary depending on the preamp and microphone model: for example, a reduction in high frequencies may occur, or a peak in the same region (the famous "air" typical of the ISA series, for example). For information, older microphones designed for radio often had a reduction above 12kHz, because until the 1970s, few people were concerned with the extreme high-frequency spectrum (and designers used this reduction above 12kHz to filter problems that appeared at higher frequencies.)

Q: But then, how did you design a preamplifier circuit that can reproduce all possible variations?
A: The only way is to design an input circuit equipped with a specific transformer, combined with enormous possibilities for variation in resistance and capacitance parameters. Then, the Liquid Channel™ physically changes its analog circuit, in relation to the convolution process, to create the replica of the desired preamp.

Q: What about electronic or tube input circuits that do not use a transformer?
A: The Liquid Channel™'s transformer is bypassed when a non-transformer preamp replica is chosen by the user (indicated by a front-panel LED). Focusrite has integrated all the necessary variations to accurately reproduce the diversity of any preamp. Resistance and capacitance values are then modified within the circuit, and the dynamic convolution process is applied to replicate the full range of preamps. Tube replicas are also covered 100% – thanks to the dynamic convolution process. Whatever the type of component in the original unit, it is also present in the Liquid Channel™.

Q: Consequently, is this a hybrid technology that offers complete freedom for accurate reproduction of the sonic character of an analog preamp or compressor?
A: Yes, the sonic character of any compressor, opto or VCA, any input circuit, transformer-based or electronically balanced (including tube), can be accurately reproduced because all the response characteristics of each unit have been precisely mapped.

Q: Why is a specific circuit needed for the preamp and not for the compressor? If the dynamic convolution process is as powerful as you say, surely no additional circuit is needed.
A: As mentioned above, the interaction between the microphone and the input circuit is a key factor in sonic character (the ISA 428 and ISA 430MKII with their impedance switch, which allow the user to adapt the circuit to their needs, are the best examples). By integrating a preamplifier circuit where the signal path is variable (transformer or electronic) and impedance values are also variable, the Liquid Channel™ can replicate the specific characteristics of the original model and ensure identical interaction. This interaction phenomenon has nothing to do with the sonic identity of a compressor, which, conversely, requires immense DSP resources. Indeed, the possibilities for threshold and ratio settings in a compressor involve taking into account numerous parameters, including large response variations (transfer function type, etc.).

Q: Is the transformer the traditional Focusrite Lundahl™? Or another known brand like Jensen™?
A: No, it's a new specific model, designed and manufactured in the UK by Focusrite's R&D department, to meet the particular flexibility needs of "Liquid" technology: transparent or colored as required.

Q: If I connect different microphones to the plethora of preamps offered by the Liquid Channel™, will each microphone present a different sound?
A: Absolutely. The results will be the same as if you connected your favorite microphone collection to different preamps. Of course, with software modeling, it would be simply impossible – how can you reproduce in real-time all the interaction particularities between a given microphone and an input circuit if that circuit doesn't exist?

Q: What about the interaction between preamp and compressor?
A: The DSPs handling the Liquid Channel™'s dynamic convolution process are separate for the preamp and the compressor. In fact, the Liquid Channel™ acts like two separate units, with the same signal leaving the preamp to enter the compressor. Thus, the interaction is identical to that of a combination of two original units, without cabling constraints or bulk, but with the reliability of a high-end digital unit.

Q: What about the equalizer?
A: Focusrite's R&D department decided that the Liquid Channel™ should include an equalizer. They therefore created a brand new digital equalizer, designed based on the curves of the famous ISA 110. This equalizer, a purely British design by Focusrite, is the perfect complement to the available range of preamps and compressors.

Q: Can I place the equalizer before the compressor?
A: Yes, you can. You can also insert the equalizer into the sidechain, as for a de-esser operation. The equalization is adjustable directly on the front panel and includes two "shelves" and a very wide-band parametric mid-range.

Q: I understand the unit is a mono model, dedicated to recording. What about stereo operation? Can I chain two units?
A: Yes, you only need two standard RCA-RCA cables to transmit data between the units. The preamp, compressor, and equalizer will then function as a stereo pair, even if you manage them via the LiquidControl™ software. With two chained units, the Liquid Channel™ also becomes the ideal device for mixing or mastering.

Q: Is there a way to achieve a direct path from the preamp to the output?
A: Yes. By not activating the compressor or the equalizer, the signal, after processing by the preamp section, will be routed directly to the digital AES output (or the analog output, via the D/A converter).

Q: What happens if I record an exceptional moment and then realize the gain was inappropriate and caused saturation?
A: The Liquid Channel™ integrates a "session saver" function that automatically protects you from this mishap if you enable it. The Liquid Channel™ can then detect the risk of saturation and reduce the input gain – a 1dB reduction for any level above 0dBfs.

Q: What are the possibilities regarding the signal path?
A: Numerous. The possibilities are as follows:

• Analog to Digital: (Microphone connected to the unit via the balanced XLR connector, A/D converter, preamp and compressor sections with DSP for the convolution process, and finally output in AES format). The D/A converter can be used as a control output, with very low latency, to avoid digital workstation delay.
• Digital to Digital: The digital input is used directly, and the signal is routed to the preamp and/or compressor convolution engines as needed.
• Digital to Analog: Similar to Digital to Digital above, but using the analog output and D/A converter.
• Analog to Analog: Similar to Analog to Digital above, but using the analog output and D/A converter.

Q: What are the specifications for the A/D and D/A converters?
A: The format is the international standard AES-EBU. All sample rates from 44.1kHz to 192kHz are supported natively, both input and output. You can send a pre-recorded instrument or a line source digitally into the preamp, or directly into the compressor.

Q: What type of A/D encoders are used?
A: The latest: 192 kHz/120 dB, AKM™ 5394s specifications.

Q: I noticed a "Harmonics" setting. What is it for?
A: Warmth is pleasant, everyone says so. Of course, the Liquid Channel™ is capable of perfectly recreating the warmth of analog circuits of "vintage" devices, as well as their other particularities. But imagine if your own old preamp, for whatever reason, had more warmth than another? (These units were mostly hand-built, so there are often more variations in production tolerances, for example). This setting offers the possibility to add a little more warmth to your Liquid Channel™ to match your specific unit.

Q: What if I want to compress before A/D conversion to get that "pushed" preamp sound?
A: You don't need to. You can now optimize the gain and then adjust the harmonic distortion ratio, as described above. Some older preamps, which sounded better when the input was "pushed", have a specific replica for this behavior.

Q: What is the unit's latency?
A: In the worst case (analog to analog, all sections operating, at 44.1kHz), it's better than 4 milliseconds. At 96kHz, analog to analog: 1.6 milliseconds. In other words, extremely short.

Q: Does the fact that impulse responses were measured in steps lead to audible differences between the replica and the original?
A: Not at all. Firstly, the measurements took into account the non-linear behavior of "vintage" units by sending impulse trains at decreasing levels, from peak level down to approximately the noise floor. The time between each impulse is long enough to allow the measured unit to return to its initial state. This means that the dynamic behavior of the measured units is integrated, unlike modeling which, to facilitate design, assumes the unit is linear.

Secondly, these "response models" are applied proportionally to all audio samples. So, at 96kHz, the signal is processed 96,000 times per second and thus accounts for all level variations! It is true, however, that this method is not 100% continuous. But the amount of data is such and the system so powerful that the margin of error is extremely small and in no case audible.

Q: What about settings available on some "vintage" models that are absent on the Liquid Channel™? How can the Liquid Channel™ replicate them accurately without these settings?
A: The available settings on classic preamps and compressors are those found on the Liquid Channel™ – threshold, ratio, attack, release, gain (some models have fewer, some "vintage" compressors only offer gain settings, for example). Focusrite also plans to provide multiple replicas for the same unit if needed. Furthermore, the Liquid Channel™ enhances possibilities by offering a setting for second, third, and fifth-order harmonic distortion, thus influencing the overall warmth provided by the preamp. This additional setting allows the user to adapt to characteristic variations between different units of the same "vintage" model. Finally, the Liquid Channel™ features a Setup menu to configure it either like the original ("as original") or to allow all available settings ("Free"), even those not present on the original.

Q: What analog components are affected when changing the Preamp?
A: The transformer and the relay matrix for the various capacitors and resistors.

Q: How is the transformer managed? Are there variations between primary and secondary?
A: Transformer variations are partly managed by resistance and capacitance variations. This transformer is substantial and large enough not to alter the circuit's load. The transformer (type 1:1) is completely transparent in itself, but it can be configured not to be if the unit being reproduced requires analog coloration. Primary/secondary variations are mainly implemented through the convolution process.

Q: Is the sound of the replicas less good at 44.1kHz than at 192kHz?
A: No. The sample rate does not affect the quality of the replicas. We are always at 32-bit floating point, and the A/D conversion is much more affected by the sample rate. Note: We do not perform any sample rate conversion because all the different rates are already stored in the SHARC chips. We have slow (44.1kHz) and fast replicas. In fact, the highest speed stored is 96kHz – no more is needed, as 96kHz is sufficient for replica application, and further refinement is well beyond psychoacoustic capabilities. This is not true, however, for A/D conversion, where an audible difference exists between 96kHz and 192kHz.

Q: Why no tubes? If a transformer is needed in the analog circuit, why not a tube as well?
A: The convolution process efficiently manages and replicates a tube. Furthermore, transformers offer other advantages besides their warmth: better common-mode rejection and the direct action of the transformer on the connected microphone, for example. This latter point is why we need a transformer to reproduce a preamp; microphone interaction is key for a transformer in a way that it is not for a tube.

Q: Is there an audible difference (distortion) between a "HOT" replica (high gain) and a normal gain replica with added second, third, and fifth-order harmonic distortion?
A: Yes. With high gain on an old preamp, you might get 60dB of gain at 1kHz and 40dB at 10kHz. Harmonic distortion occurs similarly. Third-order harmonic distortion is reduced at low gain and may therefore be present in a "HOT" replica and not in one where second-order harmonic distortion is added. This is one reason we included "HG" replicas. There are other differences: the transformer is loaded differently when high gain is applied at the input, and microphone interaction changes appear. For example, the high-frequency response will change.

Q: Why use only one impulse train to create a replica? Wasn't it necessary to perform a replica for each combination of threshold, ratio, etc., settings?
A: The convolution process, using a single impulse train, accurately reproduces the signal processing for all frequency/time variations. However, the complete process is more complex than that. Once the replica is created from the convolution, we then measured the compressor's curve for different ratio and threshold settings. Then we measured the attack and release characteristics, as well as the detection mode (peak or RMS) in the sidechain to determine its exact detection mode. (If you apply a drum kit to a peak-detecting compressor, like a Focusrite, the compressor's sidechain follows the incoming signal's curve, and compression occurs in a way that follows this curve. An RMS-detecting compressor compresses the signal based on the average level and ignores peaks. A drum kit is therefore regularly compressed by a Focusrite, whereas an RMS-detecting model exhibits less regular compression, where transients have more energy.) We then compiled all this information to obtain a compressor that acts in such a way that the incoming signal is rectified, directed to peak or RMS detection according to the unit being reproduced, accesses the curve circuit to recreate the original detection chain, and finally reaches the convolution process. This cannot be achieved at the impulse stage because the mathematical calculations would then handle amplification rather than compression.

Q: Can the digital input be sent to the preamp?
A: Yes, you can send it to any type of preamp replica, or only through the transformer, or directly to the compressor.

Specifications

Converter Performance:

• Sample Rate: 44.1, 48, 88.2, 96, 176.4, and 192 kHz
• Resolution: 24-bit
• A/D:
• Signal-to-Noise Ratio: 120dB measured over a 20 Hz/22 kHz bandwidth, A-weighted
• Frequency Response: ±0.05 dB between 20 Hz - 20 kHz
• Maximum Input Level: +22 dBu
• THD+N: 0.00035% (-109 dB)
• D/A:
• Dynamic Range: 116 dB measured over a 20 Hz/22 kHz bandwidth, A-weighted
• Frequency Response: ±0.05 dB between 20 Hz - 20 kHz
• Maximum Output Level: +22 dBu
• THD+N: 0.0007% (-103 dB)
• Jitter:
• Internal Clock: <20 picoseconds
• AES Output: <200 picoseconds
• External Clock: <3 nanoseconds

Analog and Digital Paths:

Mic Preamp:

• Gain: +6 dB to +80 dB, in 1dB steps
• Frequency Response: Variable, depending on chosen replica
• THD+N Analog Output: 0.001% for a +4 dBu input signal at 1 kHz, with 20 Hz/22 kHz filter
• THD+N AES Output: 0.0005% for a +4 dBu input signal at 1 kHz, with 20 Hz-22 kHz filter
• Noise (EIN): -126 dB for 80dB gain, 150 Ω source, and 20 Hz/22 kHz filter
• Noise Analog Output: -92 dBu for +6 dB gain with 20 Hz/22 kHz A-weighted filter
• Noise AES Digital Output: -119 dBfs for +6 dB gain with 20 Hz/22 kHz A-weighted filter
• Maximum Output Level: +16 dBu
• Input Impedance: Variable, depending on chosen replica
• CMRR: Transformer: 123 dB @ 60 dB gain; Electronic: 102 dB @ 60 dB gain

Line Input:

• Gain: +10 dB to -10 dB, in 1dB steps
• Frequency Response: 0 dB ±0.1 dB between 20 Hz and 20 kHz
• THD+N Analog Output: 0.001% for a +18 dBu input signal at 1 kHz, with 20 Hz/22 kHz filter
• THD+N AES Digital Output: 0.0004% for a +18 dBu input signal at 1 kHz, with 20 Hz/22 kHz filter
• Noise Analog Output: -92 dBu for 0 dB gain with 20 Hz/22 kHz A-weighted filter
• Noise AES Digital Output: -120 dBfs for 0 dB gain with 20 Hz/22 kHz A-weighted filter
• Maximum Input Level: +22 dBu

Low-Pass Filter:

• Cutoff Frequency: Switchable between 75 Hz and 120 Hz, -6 dB point. 12 dB per octave.

Harmonics:

• Distortion Range: 0 to 15, where maximum (15%) is 10% second-order harmonic distortion, 20% third-order, and 10% fifth-order at 0dBFs (level-dependent).

Compressor:

• In "As Original" mode, the range of settings is the same as available on the original. In "FREE" mode, the range of settings is as follows:
• Threshold: -40 dB to 20 dB in 1dB steps
• Ratio: 1:1 to Limiting
• Attack Time: 0.1 mS to 2.5 S
• Release Time: 0.1 mS to 2.5 S
• Gain: -20 dB to +20 dB in 0.5dB steps

Equalizer:

• Treble Shelf:
• Frequency Range: 200 Hz to 20 kHz
• Gain: ±18 dB
• Mid Band:
• Frequency Range: 100 Hz to 10 kHz
• Gain: ±18 dB
• Q Factor: Variable between 0.8 and 2.5
• Bass Shelf:
• Frequency Range: 10 Hz to 1 kHz
• Gain: ±18 dB

Rear Panel Connections

• Mic Input: XLR female
• Line Input: XLR female
• Analog Output: XLR male
• AES Digital Input: XLR female
• AES Digital Output: XLR male
• Wordclock Input: BNC, 75Ω impedance
• Wordclock Output: BNC, 75Ω impedance
• Digital Link Bus Input: RCA connector
• Digital Link Bus Output: RCA connector

Physical Details

Weight: 8.6 kg

Dimensions: 484 mm (W) x 85 mm (H) x 270 mm (D) / 2U 19" rack units

Legal Information

Responsibility: The impulse responses in the Liquid Channel™ are exact reproductions of the impulse responses of the replicated equipment. All manufacturer names, products, and brands mentioned in this document are the property of their respective owners. Focusrite does not express or imply any functional similarities with products developed and sold by other manufacturers, nor any convention between Focusrite and these other manufacturers or vice versa.

Accuracy: Although every effort has been made to ensure the accuracy of this document, Focusrite Audio Engineering Ltd assumes no liability for warranty regarding its content.

Copyright: Copyright 2004 Focusrite Audio Engineering Ltd. All rights reserved. No part of this document may be reproduced, photocopied, stored in any type of system, or transmitted to a third party in any form without the prior formal consent of Focusrite Audio Engineering Ltd.

Warranty: All Focusrite products are guaranteed against any manufacturing, labor, or component defects for a period of one year from the date of purchase. Focusrite UK or its authorized local distributor will endeavor to remedy any defect as quickly as possible. This warranty applies in addition to legal provisions.

This warranty does not apply to:

• Transport to or from the factory for inspection, and labor costs if the repair was not carried out by the distributor in the country of purchase or by Focusrite in GB.
• Loss or damage, direct or indirect, of any kind, caused by the aforementioned transport(s).
• Any damage or defect resulting from abuse, negligence, improper use, storage, or maintenance.

If a product defect is found, please consult the retailer in the country of purchase or the manufacturer. If the product must be returned, ensure its packaging is of good quality, preferably the original carton. We will do our best to resolve the issue as quickly as possible. For better service, please complete the warranty card provided with your Liquid Channel™.

Renunciation: The impulse responses in the Liquid Channel™ are the actual impulse responses of the replicated equipment. All manufacturer names, products, and brands to which the Liquid Channel™ or this document may refer directly or indirectly are the property of their respective owners. Focusrite does not express or imply any functional similarity with products developed and marketed by other manufacturers, nor any convention between Focusrite and these other manufacturers or vice versa.