ENGLISH
4
Lo Z (Switch) [CHANNELS 1 & 2 ONLY]
This switch changes the input impedance to the lower value of 150
(when engaged).
This should be utilised if the output impedance of the microphone is low, around 50
for example, or if a ribbon microphone is in use. Alternatively, this switch can be
activated with a higher impedance microphone to experiment with different sounds.
Ø (Phase Reverse Switch) [CHANNEL 1 ONLY]
This allows the phase of the input signal to be reversed (switch engaged), to correct
phase problems that may occur when using multiple microphones. This switch should
be disengaged (in the out position) when no phasing problems have been detected.
LEVEL (Knob)
This sets the signal level for the channel. Connect an input signal to the unit, ensuring
that the LEVEL control is set fully anti-clockwise, and increase the LEVEL control
until a signal is displayed on the front panel meter (if the channel is selected - see
METERING section) or at the destination (recording medium). The red O/L
(Overload) LED should not light, if it does you should reduce the LEVEL as this
signifies that the input has reached 0dBFS.
With a MIC INPUT connected to a rear panel XLR connector (ensure nothing is
connected to that channel’s front panel Line input), the LEVEL control provides
+14dB (fully anti-clockwise) to +60dB (fully clockwise) of gain.
With a LINE INPUT connected to a front panel balanced (unbalanced will be
accepted) 1/4” jack connector, the gain is adjustable from -10dB (fully anti-clockwise)
to +38dB (fully clockwise).
With the INST switch activated (channels 1 & 2 only) and an instrument connected to
that channel’s front panel Line input, the LEVEL control pr14dB to +60dB of
gain.
(Switch)
This is a high-pass filter, which removes unwanted low frequencies such as stage rumble
via microphone stands or ‘proximity effect’ (where low frequencies are over-emphasised
when using certain types of microphone at close range). Engaging the switch inserts a
12dB/octave, 2-pole HP filter at 120Hz in the signal path.
48V ALL ON (Switch)
This switch activates phantom power circuits for all XLR inputs on the rear panel, so
that 48V is supplied to every connected microphone. If you are using condenser
microphones then this switch will need to be engaged. If you are unsure whether your
microphone requires phantom power, refer to its user guide, as phantom power will
damage some microphones, most notably ribbon microphones. NB Dynamic
microphones will be unaffected by phantom power.
METERING
The meter on the front panel displays the level of the selected incoming signal in dBFS,
where 0dBFS (digital clipping point) relates to +22dBu. Any signal over 0dBFS will
cause the O/L LED on that channel to illuminate to indicate that the level is too high.
For most input signals, an average level of between -10 and -6dBFS is recommended.
To use the meter to view a particular channel’s level, simply use the SOURCE switch
as described below.
SOURCE (non-latching switch)
This switch selects the source signal that the meter on the front panel displays. Pressing
the switch repeatedly will cycle through the eight channels in sequence. The currently
displayed channel’s O/L LED will illuminate to indicate the selection.
DIGITAL CONVERTER OPTIONS
In addition to the analogue outputs, the OctoPre LE can be fitted with a digital
converter I/O (CODEC) option. This allows quality digital conversion of the recorded
signals within the unit before transmitting directly to the DAW (interface or
soundcard) or other recording medium. Additionally, a digital to analogue converter is
included, whereby a digital output of a DAW (interface or soundcard) can be
connected directly to the unit for monitoring purposes; all eight channels can be
converted and fed to the Line 1/4” jack outputs on the rear panel, or just 1-4/5-8 as
required (see corresponding switch details below).
The optional digital converter card features two ADAT
-type optical ‘lightpipe’
connectors, an input and output. Digital audio can be transmitted or received at either
44.1 or 48kHz sample rates (selected on the front panel) and 24-bit resolution.
