DLS Svenska AB A4 Stereo Amplifier User Manual


 
The LP-filter on the rear channels is used when
you run a 2-way or 3-way speaker system with active
crossover. It will allow low frequencies only and
blocks higher frequencies. The filter can be switched
in and out.
The normal frequency range is from 0,3 to 4 kHz.
With the LP x10 switch, under the bottom plate,
you can change the filter frequency range from the
normal to 3 - 40 kHz. A normal x-over setting is 3-4
kHz when used for active crossover in a 2-way sys-
tem.
If you run a 3-way system on the amplifier you can
use this filter for active crossover between midbass
and midrange speakers. A typical setting is 400 Hz.
The sub channel is made only for subwoofer use
and has a variable LP-filter that can be switched on-
off. A normal setting for the LP-filter is 60-80 Hz.
FRONT SPEAKERS
+LEFT- +RIGHT-
REAR SPEAKERS
+LEFT- +RIGHT-
SIGNAL INPUTS
FRONT REAR
LEFT RIGHT LEFT RIGHT
3,5V
7V 0,2V
3,5V
7V 0,2V
LEVEL
x20 change
by bottom switch
240
80 400
Hz
OUT
IN
HP-filter
240
80 400
Hz
OUT
IN
HP-filter
2
0,3 4
kHz
OUT
IN
LP-filter
LEVEL
x10 change
by bottom switch
Lowpass filter on rear channels
x10 change
by bottom switch
2
0,3 4
kHz
OUT
IN
LP-filter
Amplifier front
x 20
x 1
HP
x 1
x 10
LP
Input
Front Rear
Input
Sub
Front
input to
rear & sub
Rear
input to
sub
Sub input
from rear
Sub input
separate
LP x10 swith under the bottom plate
Filters on sub
channel
Crossovers / filters on A7
DLS A7 amplifier include highpass filter (HP),
lowpass filter (LP). On the two front channels the HP-
filter can be switched between two different frequency
ranges, likewise for the LP-filter on the rear channels.
The slope of the HP-filter is
12 dB / octave.
The filter can be switched off
if you want to run the
amplifier in full range mode.
Or use as a HP-filter for
tweeters if you want to run
a 2-way speaker system
with active crossover. The
HP x20 switch under the bot-
tom plate changes the filt-
ers frequency range from the
normal 80-400 Hz to 1600 -
8000 Hz. A normal setting is
3-5 kHz.
If you run a 3-way system
on the amplifier you can use
this filter for active cross-
over between midbass and
midrange speakers, a
typical setting is 400 Hz.
Highpass filter on front channels
Highpass filter on rear channels
8
x20 change
by bottom switch
240
80 400
Hz
OUT
IN
HP-filter
Amplifier front
x 20
x 1
HP
x 1
x 10
LP
Input
Front Rear
Input
Sub
Front
input to
rear & sub
Rear
input to
sub
Sub input
from rear
Sub input
separate
This HP-filter is normally
used as a high pass filter
blocking very low frequencies
from reaching the speakers. It
is mostly used at say 80 Hz
to protect small speakers
( like 6 inch and smaller ) from
deep bass.
The slope of the HP-filter is
12 dB / octave.
The filter can be switched off
if you want to run the amplifier
in full range mode.
240
80 400
Hz
OUT
IN
HP-filter
ULTIMATE A7
Lowpass
90
50 125
Hz