XLR connectors are located next to each other and correspond to the channels as laid out on the
front panel.
Phantom power is applied to the P48 input XLR when the phantom power switch is pressed in.
It is a good habit to apply phantom power AFTER a microphone is plugged into the XLR
connector on the SMP-2 to prevent a voltage spikes appearing at the input of the preamp
circuitry. The phantom power supply voltage on the SMP-2 is +48 VDC and is a high current
robust design to provide consistent phantom power voltage to all inputs regardless of the number
of phantom powered mics plugged into the SMP-2.
No phantom power is present on the direct coupled input (DC) XLR even if the phantom power
switch is pressed in on the front panel. PLEASE NOTE… only one of the two input XLR
connector can be used at any given time. The unused XLR should have no cable plugged into it.
Gain control on the SMP-2 variable from a minimum of +6 dB to a maximum of +68 dB (or
+74 dB if high gain option is installed) in 24 steps. The gain control use high quality Elma
switches for long life and good signal switching qualities. The gain setting for each position are
shown on the front panel graphics.
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Ventilation
The SMP-2 circuitry uses Class A discrete JFET amplifiers. These amplifiers generate a lot of
heat because of their Class A biasing, but the SMP-2 should not require extra space above or
below the unit under most conditions. Should the SMP-2 be mounted above something that
generates a lot of heat (like vacuum tube preamps), you should leave a 1U air space between the
