Samson MPL 1502 User Manual

15
Setting the Correct Gain Structure
j. The procedure for setting optimum microphone levels is virtually identical; sing
or speak into the mic at the level you expect to use in performance while slowly
raising the gain control for that channel to its center detented “0” position. Then
carefully adjust the input trim control for that channel while watching the meter,
until the “0” segment lights frequently and the “+2” segment lights only occasion-
ally. You should expect that microphone inputs will require rather more in the
way of input trim boost than line inputs.
k. If you have any outboard signal processors connected to the Aux send and
return jacks on the rear panel, follow this step. Because outboard effects
processors can sometimes be quite noisy, it’s particularly important to maximize
the amount of signal being sent to them via the MPL 1502 Aux sends. The idea
is to drive these devices as hot as possible (short of overloading them) and then
to use the corresponding Aux return level to carefully adjust the amount of
processed signal being blended with the dry signal. To set optimum Aux send
levels, use a channel that has already had its gain structure adjusted in step (g)
or (j) above. Turn both Aux send knobs for that channel to their “0” (unity gain)
position and then play the instrument (or sing into the microphone) connected to
that channel. Adjust the input levels of connected outboard effects processors
so that their meter shows incoming signal normally in the 0 vu range (with only
occasional higher excursions). Then it’s time to optimize the Aux return levels.
While continuing to play your instrument (or continuing to sing into the micro-
phone), slowly raise each Aux return level control until you hear the desired
amount of processed signal added to the dry signal. For more information, see
the “Using the Aux Sends and Returns” section on page 20.
l. The gain structure is now correctly set—you’ve optimized the level of all
signals coming into and out of the MPL 1502, and the end result will be minimum
noise and distortion and maximum clean sound. You’ll now find that the majority
of your mixes can be accomplished with most channel gain controls at or near
their center detented “0” (unity gain) position and that the channel peak LEDs
rarely if ever light (remember, if they do light, it means that something is
distorting!). If you need to make adjustments to the overall level, use the level
control of your power amplifier.
If you encounter difficulty with any aspect of setting up or using your MPL 1502,
you can call Samson Technical Support (516-932-1062) between 9 AM and 5
PM EST.

Samson MPL 1502 Specifications

Audio Specifications

frequency response	17 Hz to 30 kHz ± 1.5 dB at +4 dB
equivalent input noise channel 1-5 mic input	-128 dB (A filter, 150 Ω shorted)
equivalent input noise channel 1-15 line input	-131 dB (A filter, input shorted)
total harmonic distortion + noise	Less than 0.03 %
input level channel 1-5 mic input	-50 dBV to +4 dB (10 kΩ, balanced XLR)
input level channel 1-15 line input	-40 dBV to +14 dB (10 kΩ, balanced stereo phone jack)
input level aux return 1-2	+4 dB (47 kΩ, unbalanced phone jack)
maximum input level channel 1-5 mic input	+17 dB
maximum input level channel 1-15 line input	+27 dB
trim gain range	0 dB to +54 dB
channel fader range	+15 dB to -80 dB
aux send gain range	+10 dB to -75 dB
crosstalk ch-to-ch (1 kHz)	-80 dB
crosstalk stereo ch L/R (1 kHz)	-65 dB
standard output level main out	+4 dBV (balanced, 600 Ω loaded)
standard output level aux out	+4 dBV (unbalanced, 2.2 kΩ loaded)
standard output level headphones	150 mW (30 Ω loaded)
maximum output main out	+22 dBV (balanced, 600 Ω loaded)
maximum output aux out	+22 dBV (unbalanced, 2.2 kΩ loaded)
maximum output tape out	+22 dBV (unbalanced, 600 Ω loaded)
tone control high	10 kHz ± 15 dB
tone control mid	800 Hz ± 12 dB
tone control low	80 Hz ± 15 dB

Weight and Dimensions

dimensions	13.8 in (w) x 10.4 in (d) x 3.2 in (h)
dimensions metric	350 mm (w) x 264 mm (d) x 82 mm (h)
weight	7.7 lbs • 3.5 kg