C O N T R O L S A N D C O N N E C T I O N S
6
1. MONO INPUT SECTION
(1) MIC INPUT
The Mic input is an electroni-
cally balanced XLR type
designed to accept signals
from any balanced low
impedance (Low Z) micro-
phone. To accommodate
condenser microphones, this
input is also equipped with
+48VDC phantom power
globally switchable to all
XLR input jacks with the
Phantom Power switch
(27) in the Master Section.
Dynamic or ribbon-type
microphones do not require
phantom powering. It will be
necessary to adjust the
channel gain with the input
Trim control (4) to achieve
a nominal operating level. The XLR jack is configured for:
Pin1 = ground, Pin2 = positive (+), Pin3 = negative (-).
[Note: The Mic inputs are more sensitive than the Line inputs.
Also, do not connect mics with the phantom power switched
on, as indicated by the Phantom Power On LED (27A) next
to the Phantom Power switch. Never use unbalanced mic
cables with the Phantom Power switched on. Never short the
+48VDC to ground, as that can cause serious damage to
your mixer. Also, mute the Monitor/PA speakers when turning
the phantom power on or off.]
(2) LINE INPUT
The Line input is designed to accept balanced or unbalanced
line-level signals such as those from keyboards, drum
machines, or samplers. There is enough gain available on the
line input to accept even lower level signals, such as those
from an unbalanced microphone or guitar output. Use the
Trim control (4) to adjust for the desired level. If a balanced
signal is to be connected to the line input, then a 1/4" TRS
(stereo) phone plug should be wired for: Tip = positive (+),
Ring = negative (-), Sleeve = ground.
(Note: Only either the Mic or the Line input of a given channel
can be connected at one time. Never connect both simultane-
ously to the same channel.)
(3) INSERT
Channels 1-8 are equipped with insert jacks to connect exter-
nal signal processors, such as compressors, noise reduction
systems, or effects devices, to the individual input channels.
Insert points are useful for adding dynamic processing or
equalization to a channel or the mix. Unlike reverbs, etc.,
which are usually added to the dry signal, dynamic process-
ing is normally applied across an entire signal. Here an Aux
Send would be inappropriate. Instead the signal is intercepted
somewhere along the channel, fed through the dynamics
processor and/or EQ, then returned to the console at the
same point where it left. The insert point is normalized, i.e.
the signal is only interrupted when a plug is plugged into it.
The insert jack is located pre EQ in the channel and is config-
ured as: Tip = send, Ring = return, Sleeve = ground. The
Insert can also be used as a channel direct output by sending
the signal from the ring. To use the Insert as a direct output,
insert a 1/4" phone plug halfway into the Insert jack so the tip
of the plug connects with the ring of the insert jack. The jack
will click into place when the connection to the ring is made.
(4) TRIM CONTROL
The trim control adjusts the input sensitivity (channel gain) of
the mic and line inputs on channels 1 through 8. This control
can be adjusted to accommodate input signals from a wide
variety of sources, from the high outputs from keyboards or
drum machines to the small signal outputs of microphones.
This wide range eliminates the need for Mic/Line switching.
The best balance of S/N and dynamic range will be achieved
if you adjust the TRIM control on each channel separately so
that the Peak Indicator LED (8) for that channel lights occa-
sionally.
(5) EQUALIZER CONTROLS
All mono input channels are fit-
ted with a three-band EQ. All
three bands have up to 15 dB
of cut and boost, with a center
detent for "off". The frequency
response is flat when all three
EQ knobs are in the center
detent position. The upper and
lower shelving controls have
their frequencies fixed at 12
kHz and 80 Hz respectively.
The midrange control has a
peaking response at 2.5KHz
(Q fixed at 1 octave). The
channel EQ is an important
part of the mixer as it allows
the user to control the tonal
characteristics of each instru-
ment separately. For example,
boosting the LOW can fatten
the sound and add punch to
the bass or drums; the MID
control can be used to define
the midrange or bring out the
vocals; and adjusting the HIGH
control can provide a crisp
sounding high end. A very
important, yet often overlooked
technique is to use the EQ to
subtract from the mix. Cutting the HIGH control can reduce
unwanted hiss during multi-track recording, while attenuating
the MID or LOW can eliminate feedback in a live performance
or clear up a muddy sounding mix.
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