Microphone Preamplifier
Controls
The gain control provides continously-variable gain from +10 dB to +60 dB.
+48
is the phantom power button. When lit, it provides phantom power to the
microphone connected to the channel.
Ø
is the phase button, and reverses the phase of the channel when lit.
75 Hz
is a filter that removes very low frequencies from the signal. Use it to remove
rumble or bass lift (a proximity effect of microphones, giving a bass boost as the
singer gets closer to the microphone).–See diagram opposite.
The
Mute
switch mutes the channel (that is, it reduces the volume to zero). This can
be useful during a live performance (for example, between songs). You can mute the
channel manually, using the switch on the front panel, or you can mute it remotely
by connecting a suitable switch to the external jack socket on the rear panel. The
diagram below shows the circuit for such a switch.
When you trigger the external switch, the LED on the front panel lights. Note that
the muting circuit is optically isolated, to prevent interference from external signals.
v o i c e b o x
6
V O I C E B O X
dB
Mic
N.R.
Ext.M
60
10
20
30
40
50
dB -40
-90
-80
-70
-60
-50
+48
-20
-10 -7
-5
-3
-1
0
+1 +2
+3
+
–
Ø
75Hz
Mute
+/- 9V
(Battery or PSU)
Ring
Tip
Switch
Jack Plug
47
Ω
Summary of Contents for Green Range
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