Allen&Heath GS-R24M - Manual (Page 20)

Allen & Heath 20 GS_R24 User Guide
I/P=DAW switch
This swaps the source for the valve stage from the Mic/Line/Inst
sockets to the interface return for that channel (channels 29 & 30 on
the interface). The pre-amp Gain control will not affect the return
level when sourced from the interface, but the Drive control will.
VALVE INPUT CHANNEL
INST
I/P = DAW
POL
+48V
BOOST
60 40 -14 6
30
40
50
0
20
GAIN
MIN MAX
Drive
INST
Line/Instrument Input Jack Socket
Standard 1/4” (6.25mm) Jack socket. This is an unbalanced input de-
signed so that it can be used for instruments with either line level
(active) outputs or low level magnetic or piezo pickups.
Wired Tip=Hot(+), Ring=cold (0V), Sleeve=Chassis.
Insert Jack Socket
Standard 1/4” (6.25mm) Jack socket for unbalanced insert send and
return signals. Wired Tip=send, Ring=return, Sleeve=Chassis. Nomi-
nal level is 0dBu. The insert point is after the valve pre-amp stage.
Microphone Input Socket
Standard 3-Pin XLR socket wired as Pin 1=Chassis, Pin 2=hot (+),
Pin 3=Cold (-).
Direct Output Jack Socket
Standard 1/4” (6.25mm) Jack socket for Valve channel output signal.
Wired Tip=Hot(+), Ring=Cold(0V), Sleeve=Chassis. Nominal level is
0dBu. The source for the Direct Output is taken from pre the mas-
ter level control and is impedance balanced which means that the
source resistance to the Tip(+) and Ring(0v) contacts are matched in
order to maintain common-mode interference rejection.
REAR PANEL CONNECTIONS
FRONT PANEL CONTROLS
48V Phantom Power Switch
Applies +48V to pins 2 and 3 of the XLR input though 6k8 resistors
for phantom powered condenser microphones.
Polarity (phase) reverse switch
Reverses the polarity of the balanced input signal phases for both
mic XLR and Line jack inputs.
Line/Instrument Input Switch
Selects the source for the pre-amp from XLR to Line/Instrument
input jack. The jack input is extremely high impedance (10MΩ) and
utilises a class A FET circuit as a front end to the pre-amp. This in
itself emulates a thermionic valve input stage in its tonal quality and
saturation characteristics.
Boost Instrument level switch
Increases the gain of the FET pre-amp by 26dB when pressed. Useful
for low output pickups of when the saturation characteristics of the
pre-amp circuit are utilised.
Important! This switch is liable to cause clicks or
thumps when pressed—turn down your master
level to avoid unwanted clicks.
T
T
INSERT
DIRECT
OUT
MIC
INST
IN
LINE/