SoundCraft Spirit Folio Rac Pac - Manual (Page 8)

THE CONTROLS IN DETAIL
MONO INPUT CHANNELS 1-10
1 TRIM
The TRIM control 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 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 on the
right:
Setting the knob to the "+4U" mark gives unity
gain on the LINE input for nominal +4dBu
sources, which will be suitable for most
professional equipment. Note that some
sound equipment, particularly that intended
for semi-professional use, operates at a lower
level (-10dBV) and will therefore need a higher
gain setting to give the same output level. A
second point marked "-10U" indicates the
unity gain setting for -10dBV sources.
See "Initial Setting Up" to learn how to set the
GAIN correctly.
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 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. If you turn the PHANTOM POWER on (top
right-hand side of the mixer) 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.
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.
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 in the "Connectors" section
earlier in this manual, 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.
2 100Hz HI-PASS FILTER
Pressing this switch reduces the level of bass frequencies only, and is a real bonus for
such a small mixer. Use this in live PA situations to reduce stage rumble or ‘popping’
from microphones.
5-6
100
10
1
2
3
4
5
6
7
8
If the signal level is too low it may be masked
by the noise.
Signal Noise
If the signal level is too high, clipping distortion
may occur.
Clipped
Signal
Noise
SPIRIT FOLIO RAC PAC
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