Allen&Heath ML3000 USER GUIDE - Manual (Page 25)

ML3000 User Guide 25
PFL. Press this switch to listen to the channel pre-
fade signal in the headphones or engineers monitor
without affecting the main outputs.
The signal is displayed on the main C LED bar and
VU meters when PFL is active. To avoid confusion
the L and R meters are turned off while PFL is
active.
PFL override AFL override monitor source.
Pressing any input PFL automatically overrides any
currently selected output AFL or monitor source.
Releasing PFL restores that selection. This logic is
ideal for quickly checking channel signals while
monitoring a selected mix.
INPUT SIGNAL METER. The channel meter
displays the pre-fade signal level. It is conveniently
positioned near the fader to draw your attention to
signal activity associated with each channel fader.
The SIG LED lights to display signal presence at a
low –26dB. 0 and +6 display normal signal level,
and PK (peak) lights when the signal is within 5dB
of clipping. PK senses the signal at 3 critical stages
in the signal path, pre-insert, post-EQ pre-fader and
post-fader, to warn of potential overload. PK can
flash, for example, if the preamp is clipping while
signal reads low due to attenuation through an
inserted processor.
Checking the Channel Signal Level
When plugging in a new source start with the
channel muted or fader and sends turned down.
This prevents any unexpected signal in the
loudspeakers. Adjust the channel GAIN control for
an average channel meter reading of ‘0’ with loud
moments lighting ‘+6’. Select PAD if the signal is
still too high with gain turned down. Reduce the
gain if the signal meter red PK LED lights. It may
be necessary to re-adjust the gain if changes are
made to the equaliser or inserted signal processing.
If the PK LED lights with channel meter reading low
then check the channel for correct gain structure, in
particular the equaliser and inserted equipment
settings.
Select channel PFL to check the signal quality in
the headphones while the fader is off or channel
muted. The signal is also displayed on the main C
VU and LED bar meters providing finer resolution
and dynamic indication.
FADER. A 100mm smooth travel ALPS fader
provides +10dB gain above the nominal 0dB
operating position. Audio is not passed through the
fader. Instead, its position is read by the console
computer which produces a DC voltage sent back
to the channel to control the level of the its VCA.
The VCA replaces a conventional audio fader.
VCA GROUP Indicator. The yellow LED indicator
next to the fader lights when the channel is
assigned to one or more VCA groups.
It is also used during VCA and mute group
assignment to display channel status for individual
groups. Use the VIEW or ASSIGN functions to
check the assignment of the channel to selected
groups.
Note: If the channel is assigned to a VCA group
check that the group fader is up for normal signal. If
the channel is not muted, is routed to the mix and
have both the channel and mix faders up but no
signal then the VCA group fader may be down.
IDENT STRIP. Identifies the channel numbers and
provides a write-on area. The use of low adhesion
artist or masking tape is recommended.