Samson PL2404 - Manual (Page 15)

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You’re now ready to establish the correct gain structure—the key to getting the
best performance from the PL 2404, or from any mixer, for that matter. This is a
simple procedure that ensures optimum input and output levels so that no
unnecessary noise (caused by too low a signal) or overload distortion (caused by
too high a signal) is created. Here’s a step-by-step description of how to do so:
a. With all connections made (as described above) but with the power amplifier
and PL 2404 off, start by setting the power amplifier volume to minimum. On
the PL 2404, turn all channel Level controls fully counterclockwise (to their “
∞”
position) and set all four bus faders to their “ ∞” position. If the Main output jacks
are connected to a power amplifer and loudspeakers (as described in #2 on
page 12), set the Main Level knob to its 2 o’clock “0” position. If the Control
Room output jacks are connected to a power amplifer and loudspeakers (as
described in #2 on page 12), set the Control Room Level knob to its 2 o’clock “0”
position.
b. If you have a microphone connected to channel 1 and/or channel 3, set the
rear panel Trim knobs to their fully counterclockwise (+4) position.
c. Set all channel EQ and Balance knobs to their center detent “0” positions.
d. Set all channel Aux send knobs and all Aux return Level knobs to their fully
counterclockwise (“
∞”) position.
e. Turn on all devices connected to channel line inputs and Aux returns and set
their output level controls to unity gain or, if there is no unity gain indicated on
their output control, to maximum. If you’ve got outboard effects processors con-
nected to Aux returns, make sure they are sending completely “wet” (processed)
signal, with no “dry” (unprocessed) signal mixed in.
f. Turn on the PL 2404’s rear-panel Power switch—the Power LED in the main
section will light up. Finally, turn on your power amplifier.
g. Play an instrument connected to one of the PL 2404’s line inputs* and, while
doing so, slowly raise the corresponding channel Level control to the 2 o’clock
“0” position. Then slowly raise the power amplifier volume until you reach the
level you want to hear. If the incoming signal sounds distorted, you may need to
lower the output level of the instrument, though this will rarely occur. Conversely,
if the signal is too low even with the output level of the instrument all the way up,
something’s definitely wrong: in all likelihood, the connecting audio cable is faulty
and should be replaced.
h. Repeat step (g) above for each instrument connected to the PL 2404 channel
line inputs.
** If you’re using an instrument such as electric guitar or bass, we recommend
that you connect it to the PL 2404 with a direct injection box to ensure correct
impedance.
Setting the Correct Gain Structure