Altec Lansing 3300A - Manual (Page 4)

Operating Instructions for the Altec Lansing 3300A Series Mixing Consoles
3.2 Output Connections
The main outputs of the mixing con­
sole are electronically servo-
halanced. Bzilanced output connec­
tions may be made to the male 3-pin
XLR-type connectors. For single-
ended outputs, strap the low (—)
output (pin 3 on XLR or Ring on
‘/cl­
inch phone) to ground. Otherwise,
the electronically servo-balanced
output stage will produce 6 dB less
output signal level than with a
balanced
output connection.
Unbalanced connections may be
made to the other Vi-inch phone
(TRS) connectors. Refer to Figure 2
for typical output connections.
3.3 Insert Connections
Signal processing equipment may
easily be inserted in the signal path
by using the Vi-inch phone (TRS) in­
sert connectors. The external device
must have line level unbalanced in­
puts and outputs. The output signal
from the mixing console is on the
Tip and the input signal is on the
Ring. Tlie Sleeve is ground. Refer to
Figure 3 for a typical insert
connection.
4 OPERATION
4.1 Input Channel Controls
(Refer to Figure 4.)
The input channel is the beginning
of the signal amplification chain of
the mixer. Each input channel will
accept one signal source which may
be equalized, have effects added and
sent to the monitor and main ^stem
for the audience to hear. Each input
hcis a low-impedance microphone in­
put (the 8-pin XLR connector) and a
high-impedance microphone or line
input (V«-inch phone jack). The line
input will accept signals from an
instrument, high-impedance micro­
phone, tape/CD player, keyboard or
electronic drums or eilmost any other
audio source. Always make sure that
the channel fader (see Figure 4)
I IMUU.ANCCO
j 1 IWVT
“X
1 wjt S/ t h
^ ____pL.
EXTEBNiL
EFFECTS
PROCESSOR
Y
CHANNEL
Aid SUB
•^IS
Figure 3. Typical insert coimection.
and/or master faders (see Figure 5)
are down before plugging or unplug­
ging input sources.
1. TRIM Control: This control
adjusts the gain of the input
amplifier to accommoriaie the
wide variation in signal
strength presented to the mixer
by the endless variety of signal
sources. 1110 TRIM control
allows the amplification of each
individual input source to be
optimized. Correct setting of the
TRIM control results in the best
signal-to-noise ratio (no iiiss),
the greatest dynamic range, and
the freedom from overload dis­
tortion.
To set the TRIM control
correctly, first set the channel
fader at minimum and depress
the channel PFL switch. Make
sure
the source (mic,
instrument) that is plugged into
the channel is used at its
nominal
performance level.
Increase the TRIM level until
the level of the PFL meter
reaches 0 VU. Gradually bring
the channel fader up to Uie
desired listening level, 'iliis
insures that nominal level is
maintained
throughout the
input channel.
If the level is too low in :e
trim ’ s gain circuit, hiss . ill
occur. If the level is too high in
the TRIM circuit, overloac' is-
tortion will occur. Keeping ‘-e
channel faders at nominal 1( el
with proper setting of the
TT ; ' T
control will keep the sy^’- n
sounding its best and Is
quietest.
ALTEC LANSING^ CORPORATION • a Mark IV Company