Specifications

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labeled 48V phantom power. Check the microphone specification sheet for 9 to 52V or

12 to 48V ratings (includes almost all electrets type condenser microphones). Those few

RF condenser microphones requiring a full 48VDC for phantom power will need an

external power source (generally available from the microphone manufacturer).

On the XP100 only, 24VDC phantom power is individually selected for each input with a

jumper plug P1, P2, P3 or P4. Moving the jumper plug closest to the P1, P2, P3 or P4

marking selects phantom power for the corresponding XP100 input.

Of course, dynamic microphones don’t care if there is phantom power or how much there

is of it or whether it’s even turned on or not so long as they are properly wired with their

coil across pins 2 and 3 of the XLR connector (shield to pin 1). If they are not wired

correctly they may sound real funny with the phantom power turned on (or not at

all…maybe ever again).

LEVEL CONTROLS

Each of the three inputs is controlled by its' own audio taper potentiometer. These

controls preferably operate in the twelve-to-four o'clock range. If you consistently run the

input fader below the ten o’clock position, you should probably reduce the preamp gain

setting one step with the internal dipswitches to assure maximum headroom and control

resolution. If you have a preferred position for a particular input, you can pop out the

knob cap and reposition its' reference indicator line to the twelve o'clock position. A

selection of colored knob caps is included with the unit to allow you to color code the

inputs.

The Master control adjusts the Line Output as indicated by the LED meter. The Master

gains and output stages add 32 dB of additional gain. The Master control should normally

operate above the two o'clock position to maximize internal headroom and optimize noise

performance.

LINE OUTPUT

The output stage of the mixer, A5, utilizes a unique active balanced output driver IC, the

SSM2142, that can sense whether the connected load is balanced and floating or is

unbalanced due to either side being grounded. A balanced output load will be driven with

equal and antiphase levels on the HI and LO output lines. An unbalanced (one side

grounded) load will cause the driver IC to shut off the signal output to the grounded side

of the load and double the output level applied to the other side, thus maintaining equal

output to either type of load. The output stage will drive loads of 600 ohms and higher.

Nominal output is +4dBm with clipping at +22dBm into balanced loads. Maximum

output at clipping is reduced by 6dB when driving an unbalanced load, since the full

output swing of only one driver is available. A jumper plug, P1 located just behind the

output XLR connector selects either +4dBm line level or -50dBm microphone level

output.