Signal Input - Audiotec Fischer helix Bedienungsanleitung

1 Connecting the remote lead
The remote lead is connected to the automatic antenna
(aerial positive) output of the head unit (radio). This is
only activated if the head unit is switched ON. Thus the
amplifier is switched on and off with the head unit.
2 Connecting the battery cable
Connect the +12 V power cable to the positive terminal
of the battery. Recommended cross section: min.
16mm_.
3 Connecting the ground cable
The ground cable should be connected to a central gro-
und reference point (this is located where the negative
terminal of the battery is grounded at the metal body of
the vehicle), or to a bright bare-metal location on the
vehicle chassis, i.e. an area which has been cleaned of all
paint residues.
4 Fuses
The input fuses are connected in parallel and provide
protection against an internal equipment fault, i.e. the
system must be additionally protected by a further line
fuse located in the vicinity of the battery (max. distance
from battery: 30 cm). The fuse ratings are 3 x 25 ampe-
res, and both must be installed as the amplifier protec-
tion rating is 75 amperes (3 x 25 A).
5 Fuse Function Indication
If the fuses (4) are destroyed due to malfunction the red
LED illuminates. In normal operation the LED turns off.
6 Input Signal Switch for Inputs C and D
If there is only a mono signal in bridged mode on chan-
nel C and D the inputs can be connected with switch (6)
on position 2. A Y-adapter is not necessary. Trimode is
only possible when channels C and D are bridged. Drive
channel C and D individual on position 1.

7-10 Signal input

The A4 Competition has RCA connectors for RCA
cables that can be connected with the pre-amplifier out-
put of the line-outputs of the headunit or of a pre-ampli-
fier i.g. HXE 100. This connectors are gold-plated to
ensure a better signal transmission.
11 - 14 Level controls for input sensitivity
These controls can be used to match the input sensitivi-
ty of the individual channels - A to D - to the output vol-
tage of the connected head unit. These controls are not
volume controls and are solely intended for the purpose
of sensitivity trimming. The control range extends from
700 mV to 8 V.
15-17 CPS - Color Protection System
This LEDs show the operation mode of the amplifier
green = in operation; yellow = malfunction of the ampli-
fier, short circuit at loudspeaker output; red = overhea-
ting
If the amplifier shuts off due to overheating it can take a
while until it turns on again. This depends on the outsi-
de temperature.
18 Switch for HP/ Linear/ LP of channel A and B
To switch over the internal active crossover to highpass/
full range (linear) or lowpass of channel A and B
19 Switch for HP/ Linear/ LP of channel C and D
To switch over the internal active crossover to highpass/
full range (linear) or lowpass of channel C and D
20 - 21 Control for frequency range
This control enables to adjust the control range of the
potentiometer 22 (channel A and B) and 23 (channel C
and D) from 15 Hz up to 90 Hz on position 1, from 90
Hz up to 800 Hz on position 2 and from 600 Hz up to 7
kHz on position 3.
Position 1: Lowpass
variable
Hz
15 Hz 90 Hz
Position 1: Highpass
variable
Hz
15 Hz 90 Hz
Position 2: Lowpass
variable
Hz
90 Hz 800 Hz
Position 2: Highpass
variable
Hz
90 Hz 800 Hz
Position 3: Lowpass
variable
2K 5K
600 Hz 7 kHz
Position 3: Highpass
variable
2K 5K Hz
600 Hz 7 kHz
22 - 23 Control for level adjustment
Control to adjust the crossover frequency of stereo chan-
nel A and B (22) and C and D (23)
24 Speaker terminal for channel A and B
25 Speaker terminal for channel C and D
26 Control to raise the center frequency
This control enables the center frequency set at control
27 to be raised from 0 to 9 dB if the switch 19 is on HP
or LP position.
dB
variable
20 30 50 100 200 300 500
0 dB 9 dB
Hz
Hz
7