Thank you for purchasing a Scarlett OctoPre Dynamic, an eight channel mic-pre expansion unit incorporating high quality Focusrite analogue pre-amplifiers.
The OctoPre comprises eight natural sounding, low noise preamps with plenty of gain; eight line inputs and two high headroom instrument inputs, coupled with high quality digital conversion to ADAT format. You can now expand your studio set-up or live rig by adding Focusrite quality mic preamps and conversion to any interface with ADAT I/O.
The OctoPre has both digital and analogue outputs: in addition to dual ADAT optical ports, it also provides a balanced line output from each channel, enabling you to connect it directly to any analogue device.
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 that you take the time to read through the Guide, whether you’re new to professional audio or a more experienced user, so that you are fully aware of all the possibilities the OctoPre has to offer.
If the User Guide sections do not provide the information you need, be sure to consult support.focusrite.com, which contains a comprehensive collection of answers to common technical support queries.
Note
To download this user guide in PDF format, go to: downloads.focusrite.com.
This is Version 1.0 of the Scarlett OctoPre Dynamic user guide.
The OctoPre is an eight-channel pre-amplifier for use with microphone, line, and instrument input signals. It converts the inputs into multichannel, 24-bit digital audio at sample rates up to 192 kHz. The digital outputs are in ADAT format on optical TOSLINK connectors, which can be easily routed to ADAT inputs on your studio recording system, or any other ADAT-equipped interface using optical cables. The can transmit and receive eight channels of audio at sample rates of 44.1, 48, 88.2, or 96 kHz, or four channels at 176.4 or 192 kHz. This is provided, of course, that the interface to which it is connected is able to handle the same number of channels at the sample rate in use.
Each channel includes a switchable, “one-knob” compressor which helps to ensure that the dynamic range of signals in the OctoPre are kept under control as they are routed to your DAW (Digital Audio Workstation).
The OctoPre is an ideal “expansion” unit for adding up to eight more inputs to any audio interface with ADAT I/O.
The OctoPre is a bidirectional unit: it is also equipped with ADAT format digital inputs, and a balanced analogue output from each channel. It incorporates an ADAT-to-LINE mode, making it a perfect interface for routing tracks from your DAW to an analogue mixing console.
The OctoPre can be easily synchronised with other digital audio equipment in your studio, either as a follower to an external word clock signal, or by acting as the master clock source itself.
All operational controls and metering for all eight channels are on the front panel.
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Input gain controls 1 to 8 – eight rotary controls: adjust the input gain for the signals in Channels 1 to 8 respectively.
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O/L – each input channel has a red “overload” LED; this illuminates if the signal level causes clipping at the input to the compressor section. If this occurs, reduce the gain so that the LED stays off.
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INST 1 and INST 2 – two latching switches put Inputs 1 and 2 into “Instrument” mode. When INST is selected, the gain range and input impedance are altered (relative to LINE), and the input is made unbalanced. This optimises it for the direct connection of instruments via a 2-pole (TS) jack plug. When INST is off, the inputs are suitable for the connection of line level signals. Line level signals may be connected either in balanced form via a 3-pole (TRS) jack or unbalanced, via a 2-pole (TS) jack. Each switch has an adjacent green LED to confirm selection.
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MIC 48V (1-4 & 5-8) – two latching switches, each enabling 48 V phantom power at the XLR contacts of four inputs: Channels 1 to 4 and 5 to 8 respectively. Each switch has an associated red LED indicating that phantom power is selected.
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COMPRESS 1 to 8 – activates the compressor section of each channel, and sets the threshold level. See Compressor for further details.
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COMP – a yellow LED which illuminates when the compressor section is applying gain reduction. The LED also blinks briefly when the COMPRESS control [5] is moved from its OFF position.
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MORE – a latching switch that increases the ratio of the compressor, thus applying more gain reduction at the same setting of the COMPRESS control. An adjacent red LED confirms selection.
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Input signal level meters: eight LED bargraphs, one per channel. The input signal in each channel is metered post the input gain control and post the compressor section, so you can see the level being sent to the output.
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SAMPLE RATE – a soft switch which steps through the six available sample rate settings, the current rate being indicated by one of the adjacent green LEDs. The sample rate in use is stored in memory so that it is retained when the unit is switched off.
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SYNC – a soft switch which steps through three available digital sync sources (Internal, ADAT or Word Clock), the current source being indicated by one of the adjacent red LEDs. The source in use is stored in memory so it's retained when you switch the device off.
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– a green “Locked” LED which illuminates when the unit has locked to the available sync source, indicating that it is ready to use.
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ADAT > LINE – this soft switch modifies the operating mode of the unit. When active, incoming digital audio at the ADAT input ports is converted to analogue and made available at the rear panel LINE OUTPUT connectors. The adjacent red LED confirms that this mode is active. In this mode, the analogue inputs (Channels 1 to 8) remain routed to the ADAT digital outputs. The mode in use is stored in memory so that it is retained when the unit is switched off.
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POWER – AC power switch and green LED.
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Rack ears for mounting the OctoPre in a standard 19” equipment rack.
All inputs and outputs are on the OctoPre’s rear panel.
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MIC/LINE INPUTS 1 to 8 – 8 x “Combo XLR” sockets - connect microphones using XLR connectors or line level signals using ¼” jacks. Either TRS (balanced) or TS (unbalanced) jack plugs can be used for line level signals. Note that Channels 1 and 2 also have INST mode for the direct connection of instruments (e.g., guitar), but are otherwise identical to those for Channels 3 to 8. INST mode is selected by the INST switches [3].
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ADAT OUT – two TOSLINK connectors providing the digital outputs of the unit. Utilisation of the two connectors is sample rate-dependent, as follows:
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ADAT IN – two TOSLINK connectors providing the digital inputs to the unit when used in the ADAT > LINE mode. In ADAT > LINE mode, signals at the ADAT input(s) will be fed to the analogue line outputs following D-to-A conversion. Utilisation of the two connectors is sample rate dependent, as follows:
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LINE OUTPUTS 1 to 8 – eight balanced analogue line outputs on ¼” 3-pole (TRS) jack sockets. These connectors are always active, and normally carry the outputs of Channels 1 to 8, enabling the OctoPre to be used as a stand-alone, high quality 8-channel analogue mic pre. In ADAT > LINE mode, the connectors carry the signals applied at the ADAT IN ports [17].
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WORD CLOCK OUTPUT – a BNC connector carrying the Scarlett OctoPre Dynamic’s word clock; this may be used to synchronise other digital audio equipment.
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WORD CLOCK IN – a BNC connector for the connection of an external word clock signal; select by setting SYNC to WORD. Use this input if you have a leader reference clock which provides synchronisation for all the digital audio devices in your studio.
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AC mains – standard IEC receptacle. The OctoPre is fitted with a “Universal” power supply, and will run from any AC mains voltage from 100 to 240 V, at 50 or 60 Hz.