WIRING UP
Mic Input
The MIC input 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 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. If you turn the PHANTOM POWER on, the socket provides 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. BALANCED dynamic mics may normally be used with phantom power switched on (contact your microphone manufacturer for guidance)
The input level is set using the input GAIN knob.
The LINE input offers the same gain range as the MIC input, but at a higher input impedance, and is 15dB less sensitive. This is suitable for most line level sources.
WARNING !
Start with the input GAIN knob turned fully anticlockwise when plugging high level sources into the LINE input to avoid overloading the input channel or giving you a very loud surprise!
Line Input
Accepts 3-pole 6.35mm (1/4”) jacks, or 2-pole mono jacks which will auto- matically ground the ‘cold’ input. Use this input for sources other than mics, such as keyboards, drum machines, synths, tape machines or DI boxes. The input is BALANCED for low noise and immunity from interference, but you can use UNBALANCED sources by wiring up the jacks as shown, although you should then keep cable lengths as short as possible to minimise inter- ference pick-up on the cable. Note that the ring must be grounded if the source is unbalanced. Set the input level using the GAIN knob, starting with the knob turned fully anticlockwise. Unplug any MIC connection when using the LINE input.
Insert Point
The unbalanced, pre-EQ insert point is a break in the channel signal path, allowing limiters, compressors, special EQ or other signal processing units to be added in the signal path. The Insert is a 3-pole 6.35mm (1/4”) jack socket which is normally bypassed. When a jack is inserted, the signal path
| is broken, just before the EQ section. |
| The signal from the channel appears on the TIP of the plug and is returned |
| on the RING, with the sleeve as a common ground. |
| The Send may be tapped off as an alternative pre-fade, pre-EQ direct output |
| if required, using a lead with tip and ring shorted together so that the signal |
| path is not interrupted. | |
16 | Soundcraft MFXi MPMi User Guide Issue 1210 |
