MIC Input, Line Input, Gain, 100Hz HI-PASS Filter

MONO INPUT CHANNEL

MIC INPUT

The mic input socket at the rear of the mixer accepts XLR-type connectors and is designed to suit a wide range of BALANCED or UNBALANCED low-level signals, whether from delicate vocals requiring the best low-noise performance or close-miked drum kits needing maximum headroom. Professional dynamic, condenser or ribbon mics are best because these will be LOW IMPEDANCE. While you can use low-cost HIGH IMPEDANCE mics, you do not get the same degree of immunity to interference on the microphone cable and as a result the level of background noise may be higher. Each mic input has a switch to turn on +48V PHANTOM POWER providing a suitable powering voltage for professional condenser mics.

DO NOT use unbalanced sources with the phantom power switched on. The voltage on pins 2 & 3 of the XLR connector may cause serious damage.

Unplug any mics if you want to use the corresponding LINE Input to avoid the load presented by the mic from affecting the Line Input gain. The input level is set using the GAIN knob.

Balanced Mic Input - XLR

2. Hot(+ve)

3. Cold(-ve)

1. Screen

Balanced

Input

Unbalanced Mic Input - XLR

2. Hot(+ve)
Link 3
to 1	1. Screen
	1. Screen

LINE INPUT

Accepts 3-pole ‘A’ gauge (TRS) jacks. Use this input for sources other than mics, such as keyboards, drum machines, synths, tape machines or guitars. The input is BALANCED for low noise and immunity from interference, but you can use UNBALANCED sources by wiring up the jacks as shown below, although you should then keep cable lengths as short as possible to minimise interference pick-up on the cable. Unplug anything in the MIC input if you want to use this socket. Set the input level using the GAIN knob.

GAIN

This knob sets how much of the source signal is sent to the rest of the mixer. Too high, and the signal will distort as it overloads the channel (shown by illumination of the PEAK LED) and causes clipping. Too low, and the level of any background hiss will be more noticeable and you may not be able to get enough signal level to the output of the mixer. This is shown in the diagram below:

Unbalanced

Input

3-Pole Jack

Balanced

Unbalanced

Hot (+ve)

Signal

Cold (-ve)

Gnd/Screen

Tip

Ring

Sleeve

Setting the knob to the ‘U’ mark gives unity gain for the LINE input. Note that some sound equipment, particularly that intended for domestic use, operates at a lower level (-10dBV) than professional equipment and will therefore need a higher gain setting to give the same output level.

See ‘Initial Setting Up’ for guidance on how to set the GAIN correctly.

Clipped

Signal

NoiseSPIRITFOLIO4

If the signal level is too high, clipping distortion may occur.

100Hz HI-PASS FILTER

Pressing this switch enables a 12dB/octave Hi-Pass Filter which reduces the level of bass frequencies only, and is a real bonus on a compact mixer. Use this in live PA situations to reduce stage rumble or ‘popping’ from microphones.

SignalNoise

If the signal level is too low it may be masked by the noise.