SPL Frontliner Modular Recording Channel - Manual (Page 15)

15
Frontliner
MIC GAIN
The MIC GAIN control determines the level of preamplification. The preamplification values
cover a range from +13 dB up to + 68 dB. If the optional microphone input transformer is
installed the scaled values are to be increased by ca. +14 dB (depends upon microphone;
further information on page 27, “Information on I/O transformers”). The RK27 potentiometer
from ALPS is a high-grade model with antilogarithmic characteristic and an especially high
resolution between 20 dB and 40 dB to allow for sensitive control within this most important
range.
MIC GAIN adjustments
Amplifying a mic signal to line level should principally be done solely with the MIC GAIN
control. Deactivate all processing modules in the first place. The OUTPUT level control is used
to adjust the proper drive level for subsequent equipment, so initially it should be set to 0 dB
(12 o’clock position). The 0 dB/-10 dB switch should be set to 0dB as well to see the overall
output level (also see “0 dB/-10 dB” on page 23).
Now turn up the MIC GAIN control until the VU shows maximum values between 0 dB and
+3 dB. There is still enough headroom to prevent clipping at varying input levels. Note that
the VU meter shows average levels instead of peak levels (which can be up to 10 dB higher). If
necessary, switch the VU to PPM mode to see peak levels (see “VU/PPM switch” on page 23).
In recording high-level signals such as snare and kick, etc. it may be necessary to engage the
PAD switch (see “PAD” on page 16). You can drive the MIC GAIN harder if you know that unex-
pected input level changes are unlikely to occur. Choose the -10dB setting with the 0 dB/-10 dB
switch to extend the VU meter range accordingly.
48 V
The 48 V switch activates phantom power for condenser microphones with built-in amplifiers.
Phantom power should only be activated when using microphones that require it.
VERY IMPORTANT: All microphones with balanced, ground-free outputs, can be used with
the phantom power activated. Please be sure to deactivate phantom power with all other
microphones. Unbalanced microphones may only be used with phantom power deactivated.
Since phantom power is critical to operational safety, the Frontliner offers additional switches
on the rear panel to exclude accidental use of the 48 V switch on the front. The function of
these rear panel switches is described on the previous page.
Activating phantom power
PLEASE ALWAYS FOLLOW THESE INSTRUCTIONS TO ACTIVATE AND DEACTIVATE PHANTOM
POWER (ALSO WHEN CHANGING MICROPHONES). THE FRONTLINER’S INPUT STAGE CAN BE
DAMAGED IF YOU IGNORE THESE PROCEDURES!
1. Connect the microphone to the Frontliner.
2. Now activate phantom power to use the microphone.
3. When finished, first deactivate phantom power.
4. Wait at least one minute after deactivation of phantom power before disconnecting the
microphone!
This ensures residual current will be discharged.
Preamplifier
Control Elements
7 5 3 1 0 3 5
30 50 70 100
VU
5 3 1
VU
20
10
0 %
MIC GAIN
S-R
EDUCTION
IN STR
UMEN
T
S- DETECT
AD -OVL
13
1 4
1 5 1 6 1 8 20 2 2 24 26 28 30 33
3 6 3
9 4
2 4
5 5
2 6
1 68
INS
TR. GAIN LINE GAIN RATIO
ATTACK
LMF
MHF
LMF – / +
MHF – / + AIR BAND
TU
BE SATURATIO
N
INSTR.
LINE IN TUBE
+15 dB
ON ON
MUTE
EQ PRE
COMP.
EQ/TUBE COMP.
EXTERNAL INPUTS
DE-ES. AUTO 48 V PAD
R e c o r d i n g C h a n n e l
Ø
MAKE-UP
RELEASE
OUTPUT
Sound Performance Lab Made in Germany
ON
0
-1
-2
-3 -4
-6
-
9
-1 1
-1 2 21
16
11
6
0
-5
-9 - 16 -22 -30
-38
-4
6
-
54
-58 1.2
1 .4
1
.7
2 .0
2.3 2.7 3.0
3
.6
5.0
1
6
∞
0
1
0
2 0
3
0
4 0 50 60
7
0
80
9
0
10
0 -20
- 13
- 7. 5
-4 .5
- 2
0 1.5
3
4
5
5. 5
0.1
0.2
0 .4
1.0
2.5 7.0 16
4
0
1
30
5 30 1
000 0.03
0 .05
0. 09
0 .15
0. 25 0.4 0.65
1
.0
1.3
1
.8
2
.0
0
0
.5
1
2
3
4
5 6 7 8
9
10
1 2 1
4
16 1
9
2
0 -12
- 10
- 5
-2 .5
0 2.5
5
7.5
10
12
-12
- 10
- 5
-2 .5
0 2.5
5
7.5
10
12 -10
-8
-6
- 4
-2
0 2
4
6
8
10 680
8 20
1 k 0
1 k 5
2 k 7 3 k 4 4 k 5
6 k 5
1
0 k
13 k
15 k
30
4
0
5 0
80
125
160 200
3
00
5 00
64 0
70 0
Model 2800
GR VU VU PPM 0 dB -10 dB
THR
ESHOLD
Frontliner
6
8 1 1 1 4 1 7 1 9 2 1 23 25 26 27 29 3
2 3
5 3
7 3
9 4
1 4
2
4
3
-20
-1 8
- 12
-9
0
3
9
10
dB 1:x dB dB
dB dB Hz
Hz %
ms s
dB dB
dB
48 V PAD Ø
MIC GAIN
13
1
4
1
5
1
6
1
8
20
2
2 24
26 28 30
33
3
6 3
9 4
2 4
5 5
2 6
1 6
8
dB