Using The Scarlett Octopre; Combo Inputs; Phantom Power; Pre-Amp Gain - Focusrite Scarlett OctoPre User Manual

USING THE SCARLETT OCTOPRE

Combo Inputs

All eight of the analogue inputs use "Combo XLR" connectors. These can accept male XLR connectors,
TS (unbalanced) ¼" jacks or TRS (balanced) ¼" jacks.
When an XLR connector is used, the pre-amp automatically configures gain and impedance to
receive microphone level signals. If a ¼" connector is used, the pre-amp is set to accept balanced
or unbalanced line level signals. When INST mode is selected (on Channels 1 or 2), the ¼" input
reconfigures again to optimise for an unbalanced, high impedance signal.

Phantom Power

The two 48V switches apply 48 V phantom power to Mic inputs 1 to 4 and 5 to 8 respectively. Phantom
power is required by most condenser (capacitor) microphones. Phantom power is only applied to the
XLR contacts of the Combo connectors: thus if a group of four inputs is being used for both mic and
line (or instrument) level signals, phantom power is only applied to the microphones.
Dynamic microphones do not require phantom power, but most will operate normally with phantom
power supplied. Passive ribbon microphones do not require phantom power and may be damaged if
supplied with phantom power.
If you are unsure about a microphone DO NOT apply phantom power without checking the
manufacturer's specifications first.

Pre-amp Gain

The gain of each channel should be adjusted to suit the incoming level; louder sources will need less
gain than quieter ones. Always use the LED meters to check the signal level on each channel.
Start with the Gain control set to minimum. Play (or sing) at the loudest level that is likely to be
reached during the song, and gradually increase the gain until the meter shows orange (-3 dB). Then
lower the gain by a few dB. This should ensure that the signal level is unlikely to ever reach red (0 dB)
and overload the A-to-D converter, which would result in distortion.

Pad Switch

Each channel of the Scarlett OctoPre is equipped with a switchable 8 dB PAD. Selecting PAD increases
the headroom of the input stage, and should be used to reduce mic or line level signals which are
'too hot'. It is not intended for use with the Instrument inputs in Channels 1 or 2. The associated red
LED illuminates when PAD is selected.
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