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6. CONSIDERATIONS
6.1. Starting up
You can power up this unit by pressing the power switch (11). Although powering up noise is
minimum, it is advisable to power up all your devices by following this sequence: sound sources, mixing
unit, equalizer and - finally - power amplifiers. Powering down sequence must be identical but in reverse
order. By following this simple rules you will avoid any peaks or transitories produced by these devices to
reach the following elements of the chain.
6.2. Gain, equalization, level indicators
GAIN
The SAM312 provides with an efficient way of trimming the input sensitivities, which allows the
different signal levels from all your sources to be matched. This system uses some bridges or "jumpers"
which allow a direct connection to the terminals located on the circuit board itself (see configuration
diagram).
The mixer is shipped with the following factory adjust for sensitivities and levels:
MIC:
-50dBV
LINE:
0dBV
MIX:
0dBV
OUT:
0dBV
EQUALIZATION
Tone controls (3, 4, 5) provide a gain/attenuation of ±15dB for each of the three bands, which are
centered at 100Hz, 2kHz and 10kHz. Because of the intended applications of this unit, it has a tone control
system that needs a screwdriver to be used in order to perform the adjust, thus avoiding any error during
the normal use procedure.
LEVEL INDICATORS
These indicators (6) monitor the signal level at the MIX. The nominal internally-adjusted output level
corresponds to 0dB.
6.3. Headphones
Headphones output (10) monitors the same signal present at outputs with its own volume control
(9).
