MACKIE ProFX12 - Manual (Page 23)

23
Owner’s Manual
Owner’
s Manual
40. USB THRU
In addition to a mix of the other channels, the USB
output to the computer may contain any input from
the computer if this switch is down. (This switch only
affects the output to the computer, not the headphones
or main mix.)
• If disengaged (out), the USB output to the
computer will just be the main mix. This is a
good position for overdubbing, as any playback
from the computer may be played through the
main speakers and headphones, while playing
along with a guitar and recording only the
guitar via USB. This is also good for live
recording as a safeguard against feedback.
Here, the USB level knob should also be down.
• If pressed in, the USB output to the computer
will be the main mix, including any audio
coming in from the computer. This is a good
position to record live performances where
playback of audio from the computer is also
part of the performance.
41. PHONES LEVEL
This controls the volume of the headphones output
from off to maximum gain.
Warning: The headphone amplifier is
designed to drive any standard headphones
to a very loud level. It can cause permanent
hearing damage. Even intermediate levels may be
painfully loud with some headphones. Be careful!
Always start with the phones level control turned all
the way down before connecting headphones or making
any connections. Keep it down until you’ve put on the
headphones, and turn it down first whenever you play a
new source or instrument.
42. OL LED (for stereo returns)
This LED will light if the signal coming into the
stereo return inputs [11] is too high, and this may
cause distortion due to overloading.
The OL LED comes before the stereo return fader
[44], so the fader has no effect in your efforts to turn
off the OL LED.
Check external processors and other devices, and
turn down their levels until the OL LED does not come
on.
43. MUTE (for stereo returns)
Press this switch in to mute the signals coming into
the stereo return inputs [11].
44. STEREO RETURN FADER
Use this fader to lovingly adjust the level of any audio
coming into the stereo return inputs [11] from external
processors or other equipment. The audio is added to
the main mix and it may also be muted with the stereo
return mute switch [43].
Typically, this fader can just live at the unity “U” mark,
and the external device’s output control set at whatever
they call unity gain (check the manual of the effects
unit, CD player, drum machine, or whatever). If that
turns out to be too loud or too quiet, adjust the external
device’s outputs, not the mixer. That way, the mixer’s
faders are easy to relocate at the unity “U” mark. The
range is off to +10 dB.
45. FX RETURN FADER
Use this fader to gently adjust the level of the stereo
output from the internal FX processor being added to
the main mix. The range is off to +10 dB with unity at
“U”.
46. MONITOR FADER
This fader controls the overall level of the monitor
send signal sent out to the stage monitors.
Adjust it carefully and check that the band is happy
with the levels. The fader does not affect the main mix
level.
The monitor send signals are off with the fader
fully down, the “U” marking is unity gain, and fully
up provides 10 dB of additional gain.
47. MAIN FADER
This fader controls the level of the main mix and
affects the meters [33] and main line-level outputs
[3, 14]. The level adjustment occurs after the stereo
graphic EQ [36] in the signal path.
This gives you ultimate control over the audience.
Adjust it carefully, with a good eye on the meters to
check against overloading and a good ear on the levels
to make sure the audience is happy.
The control does not affect the monitor send [12],
tape output [18], headphones [16], or USB output [4].
The main mix signals are off with the fader fully down,
the “U” marking is unity gain and fully up provides
10 dB of additional gain. This additional gain will
typically never be needed, but once again, it’s nice to
know it’s there. The level control is stereo, as it affects
both the left and right of the main mix equally. This is
the control to turn down at the end of the song when
you want “The Great Fade-Out.”