15
1
Line Input
6-channel pre-amplifier input to connect signal
sourc es such as radios. Input sensitivity is
factory-set to 4 Volts (maximum CCW position). It
is possible to vary the sensitivity between 2 and
4 Volts.
2
Clipping LED
This LED lights up red if one of the six
Line Inputs
or
Highlevel Inputs
is overdriven. The LED has no
function if the device is fed with digital input signals.
If this LED lights up reduce the input sensitivity by
using the control 3 (
Input Sensitivity
) until the LED
goes out.
3
Input Sensitivity
This control is used to adapt the input sensitivity of
the low- and highlevel inputs to the output voltage
of the connected signal source. This is not a volume
control, it´s only for adjusting the signal processors
gain. The control range of the RCA /
Line Input
is
2 - 4 Volts and 3.5 - 11 Volts for the
Highlevel Input
.
Attention:
It is mandatory to properly adapt the in-
put sensitivity of the DSP.2 to the signal source in
order to avoid damage to the signal processor.
If the
Highlevel Input
is used in combination with a
standard car radio we recommend an input sensitiv
-
ity of roughly 9 Volts. For this purpose, turn the
control from max. CCW position to 8 o’clock posi
-
tion.
4
Highlevel Input
6-channel highlevel loudspeaker input to connect
the signal processor directly to loudspeaker outputs
of OEM / aftermarket radios or OEM amplifiers that
do not have any pre-amplifier outputs. Input sensi
-
tivity is factory-set to 11 Volts (maximum CCW po
-
sition). It is possible to vary the sensitivity between
3.5 and 11 Volts with control 3 (
Input Sensitivity
).
Attention:
Solely use the pluggable screw-terminal
for the highlevel connector which is included in de
-
livery or an optional available cable harness from
the HELIX accessory assortment!
Important:
It is strictly forbidden to use the
High
level Input
and pre-amplifier inputs (
Line Input
) at
the same time. This may cause severe damage to
the pre-amplifier outputs of your car radio.
5
Optical Input
Optical input in SPDIF format for connecting signal
sources with a digital audio output. The sampling
rate of this input must be between 12 and 96 kHz.
The input signal is automatically adapted to the in-
ternal sample rate. In order to control the volume of
this input, we recommend to use an optional remote
control.
Notice:
This signal processor can only handle ste-
reo input signals and no Dolby-coded digital audio
stream.
6
Power Input
This input is used for connecting the signal pro-
cessor to the power supply of the vehicle and for
remote in / out. If the highlevel loudspeaker inputs
are used the remote input can be left unconnected.
The remote output is used for turning on/off ampli-
fiers that are connected to the
Line Outputs
of the
HELIX DSP.2. Connect this remote output to the
remote inputs of your amplifier/s. This is essential
to avoid any interfering signals. The remote output
is activated automatically as soon as the booting
process of the DSP is completed. Additionally this
output will be turned off during the “Power Save
Mode” or a software update process.
Attention:
Solely use the pluggable screw-terminal
which is included in delivery!
Important: Never use a different signal than the
remote output of the DSP to activate connected
amplifiers!
7
Ground lift switch
The ground of the HELIX DSP.2 signal inputs is gal-
vanically decoupled from the ground of the signal
outputs. In many cars this setup is the best way to
avoid alternator noise. Nevertheless, there are use
cases where it will be necessary to directly con-
nect input and output ground or to tie both grounds
together via a resistor. Therefore the
Ground lift
switch
has three positions:
-
center
position: input and output ground
separated.
- left position: input and output ground tied
together.
-
right
position: input and output ground
connected via 200 Ohms resistor.
Initial start-up and functions
