Thank you for purchasing this Clarett⁺ Octopre, the studio-grade eight-channel mic preamp with ADAT connectivity, designed for engineers and producers who need extremely high-quality inputs and outputs. Eight next-generation, high-headroom, low-noise, low-distortion Clarett+ mic preamps — featuring the unique all-analogue Air function — help you capture superbly clear recordings with precise clarity. The independent A-D and D-A converters with ultra-wide dynamic range let you hear the truth and bring you and your collaborators closer than ever to your music.
Clarett⁺ Octopre is the studio upgrade that connects all your equipment and makes high-quality multitracking easy. Used in conjunction with Clarett+ 2Pre, Clarett+ 4Pre or Clarett+ 8Pre — connecting via ADAT — it’s the ideal companion for any multichannel recording session.
This User Guide provides a detailed explanation of the hardware to help you achieve a thorough understanding of the product’s operational features. We recommend you take the time to read the Guide, so you are fully aware of all the possibilities the Clarett⁺ Octopre has to offer.
This is Version 5.1 of the Clarett⁺ Octopre user guide.
Note
To download this user guide in PDF format, go to: downloads.focusrite.com.
The Clarett⁺ Octopre is an eight-channel preamplifier for use with microphones, line and instrument input signals. Both analogue and digital outputs are provided: the digital outputs are in ADAT format on optical TOSLINK connectors, which can be easily routed to any ADAT-equipped interfaces using optical cables. The Clarett⁺ Octopre 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.
The Clarett⁺ Octopre has eight next-generation, high-performance Clarett+ preamps to capture the clearest and most powerful audio with a preamp design that brings masses of headroom, low distortion and low noise.
The new and improved high-performance A-D and D-A converters deliver extremely low noise and high dynamic range audio, for making recordings that are more powerful than ever. Switchable channel inserts on every channel keep Clarett⁺ Octopre at the centre of your creative process and its word clock input offers convenience and reliability for your system.
The ADAT inputs allow you to connect to an interface’s ADAT output - such as on the Clarett+ 8Pre – to increase the number of output channels of your recording system.
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INPUTS 1 & 2 – Combo XLR input sockets - connect microphones, instruments (e.g., guitar), or line level signals via XLR or ¼” jacks as appropriate. Either TRS (balanced) or TS (unbalanced) jack plugs can be used for instruments or line level signals.
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INST 1 & INST 2 – two switches to set Inputs 1 and 2 to “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 a red LED to confirm choice.
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48V – two switches enabling 48 V phantom power at the Combo connectors’ XLR contacts for mic inputs 1-4 and 5-8 respectively. (Note that inputs 3 to 8 are on the rear panel.) Each switch has a red LED to show when phantom power is enabled. Note that not all microphones require phantom power. If you are unsure whether your microphone needs it to work, please read the microphone documentation.
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Gain 1 to 8 – eight rotary controls: adjust input gain for signals at Inputs 1 to 8 respectively.
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O/L – each input channel has a red “overload” LED; this illuminates when the signal level reaches +19.5 dBu. Always adjust the level so the LED does not illuminate: to avoid clipping.
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INSERT/AIR – one switch per channel, which enables either the rear panel insert point for the channel, or the channel’s AIR function, depending on the setting of the INSERT and AIR main switches [8]. Each switch has an associated LED, which illuminates green when INSERT is selected or yellow when AIR is selected.
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Meters – eight 6-segment LED meters shwoing the signal levels of the eight analogue input signals. The input meters show signal level after the input gain stage. The LEDs illuminate at -42, -18 and -12 dBFS (green), -6 and -3 dBFS (yellow) and 0 dBFS (red). always avoid 0dBFS, this shows digital clipping.
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INSERT and AIR function main switches: two switches with internal LEDs (INSERT = green, AIR = yellow) which determine the function of the per-channel INSERT/AIR switches [6].
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SAMPLE RATE – a switch which steps through the six sample rate settings. The current rate is shown by a green LED. The OctoPre stores the sample rate in use so it is retained through power cycles.
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SYNC – a switch which steps through three available digital sync sources (Internal, ADAT or Word clock), the current source being shown by one of the adjacent red LEDs. The OctoPre stores the Sync source in use so it is retained through power cycles.
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(Locked) – a green LED which confirms clock synchronisation, either to the Clarett⁺ Octopre’s internal clock or to an external digital input.
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ADAT > LINE – When disabled, input Channels 1 to 8 feed both the rear panel LINE OUTPUT connector (analogue) and the ADAT output ports (digital). When ADAT>LINE mode is enabled, the signals present at the ADAT input ports are sent to the OctoPre’s LINE OUTPUT connector. This allows you to add 8-channels of analogue outputs to your system. The red LED confirms this mode is enabled. 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 it is retained when the unit is switched off.
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POWER – AC power switch and LED.
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Rack ears for mounting the Clarett⁺ Octopre in a standard 19” equipment rack.
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INSERTS 1 & 2 – two ¼” TRS jack sockets, providing an access point for connecting external processing equipment into Channels 1 and 2. The inserts are enabled by the front panel INSERT/AIR switches [6] and [8], and are unbalanced. The sockets are wired as follows:
Note that the front panel O/L LED [5] monitors signal level pre the insert send so excessive signal level is not sent to external equipment.
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INSERTS 3 to 8 – 6 x ¼” TRS jack sockets providing the insert points for Channels 3 to 8; these are electrically identical to [16].
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OPTICAL OUT – two TOSLINK connectors providing the digital outputs of the unit. Use of the two connectors is sample rate-dependent, as follows:
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OPTICAL IN – two TOSLINK connectors providing the digital inputs to the unit when used in the ADAT>LINE mode. Note that these are NOT “digital” inputs to Channels 1 to 8, and signals applied at these ports do not pass through the AIR circuitry, nor are available at the inserts. Use of the two connectors is sample rate dependent, as [18].
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LINE OUTPUTS 1 to 8 – eight balanced analogue line outputs on a 25-pin female D-sub connector. This connector is always active, and normally carries the outputs of Channels 1 to 8, enabling the Clarett⁺ Octopre to be used as a stand-alone 8-channel analogue mic pre. In ADAT > LINE mode, the connector carries the signals applied at the OPTICAL IN ports [19]. The pinout of the connector follows the “Tascam” standard for 8-channel analogue interfaces:
Pin
Function
Pin
Function
1
Output 8 ‘hot’ (+)
14
Output 8 ‘cold’ (-)
2
Output 8 Gnd
15
Output 7 ‘hot’ (+)
3
Output 7 ‘cold’ (-)
16
Output 7 Gnd
4
Output 6 ‘hot’ (+)
17
Output 6 ‘cold’ (-)
5
Output 6 Gnd
18
Output 5 ‘hot’ (+)
6
Output 5 ‘cold’ (-)
19
Output 5 Gnd
7
Output 4 ‘hot’ (+)
20
Output 4 ‘cold’ (-)
8
Output 4 Gnd
21
Output 3 ‘hot’ (+)
9
Output 3 ‘cold’ (-)
22
Output 3 Gnd
10
Output 2 ‘hot’ (+)
23
Output 2 ‘cold’ (-)
11
Output 2 Gnd
24
Output 1 ‘hot’ (+)
12
Output 1 ‘cold’ (-)
25
Output 1 Gnd
13
n/c
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WORD CLOCK OUTPUT – a BNC connector carrying the Clarett⁺ Octopre’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 W/CLOCK. 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 socket. The Clarett⁺ 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.