Samson MPL 1640 - Manual (Page 7)

Guided Tour - Channel
6: Bus switch (gray) - When up, the channel’s signal is routed to the Main L/R
faders (as described on page 7) and then on to the MPL 1640 Main Mix output
jacks (as described on page 8). When pressed in, the channel’s signal is
removed from the Main L/R output and is instead routed to the 3/4 Level knob
(as described on page 6) and then to the 3L/4R output jacks (as described on
page 8). If you don‘t have anything connected to the MPL 1640 Bus 3/4 output
jacks, this switch can be used for channel muting. See the “Using Bus 3/4”
section on page 17 for more information.
7: Peak LED (red) - This warning light indicates an overload situation. It lights
whenever a channel’s signal is 5 dB short of clipping. To stop it from lighting
(and to eliminate the accompanying sonic distortion), turn down the channel’s
Trim knob (see #1 on the previous page) or reduce the amount of equalization
boost. See the “Setting the Correct Gain Structure” and “Using Equalization”
sections on pages 12 and 19 for more information.
8: Channel fader (gray with a blue line) - This linear slider determines the signal
level being sent to the main output as well as affecting the signal level being
routed to Aux sends 2 and 3 (which are post-fader; Aux 1 is always pre-fader).
In practice, you will use the channel faders to continuously adjust the levels of
the various signals being blended together by the MPL 1640. The detented “0”
position of the fader indicates unity gain (no level attenuation or boost). Moving
the fader down from the “0” position (towards “-
∞”) causes the signal to be atten-
uated (at the very bottom, it is attenuated infinitely—in other words, there is no
sound). Moving it up from the “0” position (towards “+15”) causes the signal to
be boosted by as much as 15 dB.
For best signal-to-noise ratio, all faders for channels carrying signal should gen-
erally be kept at or near the “0” detented position. Channels that are unused
should have their faders kept all the way down at their "-
∞" (minimum) level. See
the “Setting the Correct Gain Structure” section on page 12 for more information.
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