HELIX P SIX DSP Handbuch Seite 21

Jumper positions for extended adjustment range:
A2 B2
Jum- Posi- Value range
per tion
A 2 Highlevel A - D: 10 – 20 Volt
RCA
B 2 Highlevel E - F: 10 – 20 Volt
RCA
The sensitivity range of the pre-amplifier inputs
E and F can also be changed to connect even
mobile devices with significantly lower output
voltage (like smartphones) by repositioning
jumper B. The input sensitivity is adjustable
from 170 mV to 340 mV if jumper B is inserted
into the marked position in the picture below.
Aux jumper position for RCA inputs E and F:
B3
Jum- Posi- Value range
per tion
B 3 RCA E – F: 170 mV – 340 mV
Important: To change the position of a jumper
it has to be removed by pulling it straight up-
wards. Make sure that the jumper is reinsert-
ed properly and all pins are fully inserted. The
position of each jumper can be changed inde-
pendently.
Follow the subsequent steps if you like to per-
fectly adapt the amplifiers input sensitivity to
your audio source by using the potentiometers:
1. Don't connect any amplifiers or loudspeak-
ers to the outputs of the HELIX P SIX DSP
during this setup.
2. Adjust the volume of your radio to approx.
A - D: 4 – 8 Volt
E - F: 4 – 8 Volt
90 % of the max. volume and playback a
1 kHz full scale test tone (0 dB) via CD
drive.
3. The adjustment will be easier when you
connect and adjust one input channel after
each other.
4. If the Clipping LED already lights up, you
have to reduce the input sensitivity via
the respective potentiometer until the LED
turns off.
If the potentiometer is already set to maxi-
mum CCW position then it will be necessary
to change the sensitivity range by reposi-
tioning the internal jumper.
5. Increase the input sensitivity by turning the
respective potentiometer clockwise until the
LED lights up. Now turn the potentiometer
counterclockwise until the Clipping LED
turns off again.
6. Repeat this process for each channel pair
you are using.
4. Connecting a digital signal source
If you have a signal source with an optical digital
output you can connect it to the amplifier using
the appropriate input.
In standard configuration the HELIX P SIX DSP
automatically activates the used digital input if
a digital audio signal is detected. This function
can be deactivated via the DSP PC-Tool soft-
ware. Alternatively you can manually activate
the digital input if you are using the optional re-
mote control. The automatic turn-on circuit does
not work when the digital input is used. There-
fore it is mandatory to connect the „Remote In"
(REM).
Please note that it is possible to connect a
source to the digital input and the highlevel or
the pre-amplifier at the same time.
Important: The signal of a digital audio source
normally does not contain any information
about the volume level. Keep in mind that this
will lead to full level on the outputs of the HELIX
P SIX DSP and your connected amplifiers. This
may cause severe damage to your speakers.
We strongly recommend to use an optional re-
mote control for adjusting the volume level of
the digital signal input!
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