DLS CAT31 Instruction sheet

How to install and
operatethe
DLS CAT31
24Vamplifier
Welcome!
This owners manual is written in easy english and
uses a lot of drawings to simply the installation and
use of the above amplifier.
YourDLSamplifiermustbeinstalledcorrectlyinor-
der to work well. This manual will show you how to
installtheamplifierlikeapro.Pleasereadtheentire
manualbefore beginning the installation.
Installthe amplifieryourself if youfeel confident with
our instructions and if you have the proper tools.
Howeverif you feelunsure,turn over the installation
job to someone better suited to it.
Warranty Service
Thisamplifier is covered bywarranty, dependingon
the conditions in the country where it is sold. If the
amplifier is returned for service, please include the
originaldatedreceipt with the product.


 Technical Assistance
Fortechnicalassistanceasktheshopwheretheproduct
was sold or the distributor in your very country.
You can always phone the DLS Helpdesk in Sweden
+ 46 31 84 00 60 or send an e-mail to [email protected].
Information can also be found on our WEB-site
www.dls.se
Contents
Specifications.............................. 1
Features…………………………….. 2
Installation…………………….……. 2
Troubleshooting…………………… 2
Tools and materialsneeded………. 3
Amplifier installation kit………….... 3
RoutingWires…………………….... 3
Wiring
Powerand Outputs……………..…. 4
Inputsand controls………………... 5
Input level control.......................... 5
Crossovers…………...................... 5-6
Phasecontrol.....………………...… 5
Speaker wiring:
Front stereo speakers................... 6
Subwoofers.................................. 6
Test............................................. 6
Connectinga center channel speaker 7-8
Professional tips…………...…….... 9
Approvalof electromagnetic compatability according
to the EEC Directive 95/54/EC
DLSSvenska AB- 2005-01-20

CAT31 -24 Volts - features
RCAstereo channels input


High level input with auto start
Monochannel:RCA input or input from stereo
channels
Continuousvariable low pass crossover


Continuousvariable high pass crossover


Subsonic filter 25 Hz fixed ON-OFF
Phasecontrol cont.variable0-180 degrees
Electronic protection circuitry against
short-circuit,DCoffsetandthermaloverload.
Installation
Before you begin the install
Beforeyou begin youneedto read the manual,tohave
sometools, cables and other material available. There
is one such list of material on the following page.
Amplifier location
Important
Allow air circulation aroundtheamplifier.
2
Disconnect Battery
Beforestartingtheinstal-
lation,alwaysdisconnect
the negative terminal of
the battery.
The DLS Classic series of amplifiers have a
compact design that allows great flexibility in
mounting. You can mount it under a seat or in the
trunk.
When you select a location, do remember that the
amplifier generates a lot of heat.
Choose a location where air can circulate freely
aroundthe amplifier.Donotcover theamplifierwith
carpetsor hide behind trim panels.
Donot mount the amplifier in an inverted or upside
downposition.
Checkalllocationsandplacementscarefullybefore
making any cuts, drilling any holes or making any
connections.
This is the best direction to
mount the amplifier to get
the best cooling.
CAT31
DLS logo on amplifier cooling flange
The DLS logo on top of the amplifier is attached
with two hex. screws. The logo can be removed
and twisted 90 or 180 degrees, and then screwed
backinwanted position. The logo can be mounted
in four different ways to match your installation.
If problems occur during the installation, or later,
this guide might help you to find out whats´s wrong.
The amplifier is dead:
1. Checkpowerlead, ground and connections at
the amplifier using a multi meter.
2. Check the battery terminal connections.
3. Check the power lead fuse or circuit breaker. If
fuse damage continues, inspect the power lead
for short circuits.
4. Check the amplifier protection fuses.Are these
broken change to new ones with the same value.
If short circuiting continues, contact your local
DLS dealer.A fault may exist in the amplifier.
5. To start the amplifier requires a remote voltage
of 12-30 volt. Check the voltage with a multi
meter.
Amplifier protection fuse blows at low
volume:
One or more speaker cables are shorted. Make an
insulation test with a multi meter. The cables must
not have a connection to earth.
The amplifier turns off after 10-30 minu-
tes:
Theamplifier is overheatingdueto inadequate venti-
lation. Check mounting position is free from
obstruction.
Do this:
1. Move the amplifier to a place with better ventil-
ation.
2. Install one or two fans to cool down the heat-
sink.
3. Overheating can also be caused by an
impedance load below the level permitted.
No output from the speakers:
Check the following:
1. Speaker cable connections to both amplifier and
subwoofers.
2. Signal lead plugs and cables.
Trouble shooting

Tools and material needed
Tools:


Flat and Phillips screwdrivers


Wirecutter


Wirestripper


Electric drill with drills


Crimpingtool


Digital multimeter or test lamp


Wirebrush,scraperorapiece
of an abrasive sheet to remove
paintfor a good ground connection
Greaseto protect the ground
connectionfrom corrosion
Material:
Speakerwire: minimum
12AWG = 4 mm2for subwoofers
Sheet metal screws for mounting the
amplifiertotheamplifierboardand the
amplifier board to the car + some extra
forfuseholder,amplifier ground etc.


Electrical insulation tape
½ inch thick plywood or particle board for
theamplifiertobemountedupon.
Amplifier installation kit:
If available,buy an amplifier installation kit. It
contains normally all you need. This is what you
have to buy if you buy the items separately.
Power cable, AWG 7 = 10 mm2 or heavier
1 pc of fuseholder to install close to the
car battery + fuse 40Ampere.
20 feet ofAWG 15 = 1,5 mm2wire for
remote turn on / off cable from radio.
RCA-cablefor input from radio.
- 20 feet or 5 meter for trunk installations
-12 feet or 2 – 3 meter for under seat
installations
Onemin. 8 gauge ring crimp terminal
forthe amplifier ground connection.
Wire ties
Insulatinggrommet or insulating tube
Stereo
headunit
3
Professional Tip:
If amplifier installation kits are available with diffe-
rent size of power cable, chose the most heavy
power cable to improve sound quality and to allow
more amplifiers to be installed now or later.
If possible buyAWG 5 = PL16 mm2(or heavier)
cableforbest performance.
High current draw
TheCAT31-24 Volt is anamplifierwithhighpowerout-
put. The current draw is also high so you must make
sure that your vehicles power system (battery and
alternator) can provide all the power you need. If you
have a bad battery or alternator in can result in a poor
soundoreven worse, a broken battery or alternator.
CAT31
Routing wires

Wiring
Power and Outputs
CAT31
Power terminal ( +24V)
+12V REM GND
Remote terminal ( REM )
For RCA cable signal input:
Connecttheradio powerantenna lead= remoteturn
on/off from the car stereo to the amplifier remote
connection. This turns on the amplifier whenever
the car stereo is turned on.
You can either use the built in remote cable in the
RCA cable itself or use a separate cable.
Sometimes a small disturbance may enter the
amplifier coming from the remote voltage , through
thebuiltin remotewire andinto theRCA cable.Thus
we recommend to use a separate remote wire and
runthe RCAleadseparate fromremotewire, power
cables and speaker cables.
You can either use a crimp fork terminal or insert
thecable directly into the amplifier terminal. If there
is no remote voltage available from the stereo, you
must connect to the ignition key through the radio
or any accessories fuse.
4
DLS
DLS FH 1B
fuse holder
Connect to a good chassis ground. The ground
connectionshouldbe clean,unpainted metalto prov-
idea good electricalconnection.Use a wirebrush,a
scraper or a piece of an abrasive sheet to clean the
metal. Use a lock washer or two to secure contact.
Protect with silicon grease or by paint applied
afterwards.
+12V REM GND
+12V REM GND
Power Light / Protect light
Thepower light (green ) comes on when
the amplifier is turned on.
The protect light ( red ) comes on when
the amplifier shuts down from
overheatingorshortcircuit.
Fuses
Useonly20 ampereATC blade
type fuses. CAT31 uses two 20
amperefuses.
20A
For High Level input:
Werecommend you to connecttheremote wire as
describedabove.
The amplifier will be turned on/ turned off by the
high level input voltage. This is done when the Hi
level/Low level switch is set to Hi level position.
There is a small disadvantage that this function
gives soft turn on operation but some plop sound
when switching off.
You do not have to connect any remote voltage
when using Hi level input.
Connect the fuse holder as close to the vehicle
battery + as possible, usingAWG7 = 10 mm2 or
heavier cable. Use ring crimp terminal cable to
connect to battery +.Apply silicon grease to the
fuse to prevent corrosion.
The fuse value depends on the
size of the power cable.
A 16 mm2cable can have a
60Afuse.
Connect the battery cable to the +24 Volt terminal
onthe amplifier.
Be sure to use a rubber grommet or a plastic
insulating tube where the cable passes the firewall
or other places when it can easily be jammed.
Usewiretiestosecuretoexistingcablesintheengine
room. If you buy another power cable than the
recommended, use the follwing maximum fuse
values.
Max. fuse value for different cable sizes:
6 mm2(9AWG) :25A 10 mm2 (7AWG) :40A
16 mm2 (5AWG) :60 A 21 mm2(4AWG) :100 A
33 mm2(2AWG) :150 A 42 mm2 (1AWG) :200A
+24VREM GND
+24VREM GND
+24VREM GND
Protect
(Red)
Power
(Green)
Ground Terminal ( GND )

Important
Use either the low level or the high level input, do
not use both at same time.
Low level input
Usea pairofshielded stereoaudiocables withRCA
typejack.Thecable lengthvariesdependingon type
ofvehicle.Mostcablescanbe
bought in lengths from 1 up
to 5,5 meters.
Avoid placing the RCAcable
close to speaker cables,
power cables and remote
control cable. Connect to in-
put socket A & B.
High Level Input
Connect left and right speaker wires coming from
the car stereo to the high level input as shown. You
mustconnect both plus andminusasthe inputs are
balanced,connectingplus onlygives lowerlevel and
bad sound quality. By changing the polarity of plus
and minus, you can change the phase.
Hihg level input socket.
Automatic turn on when using high level input.
WiththeHi/Lowinput swichset toHi, theamplifier turns
onautomaticallyonhighinput.Youdon´tneedtoconnect
aseparateremotewirefromyourheadunit.
When using High Level input:
Set the switch to position ”Hi / Level”
When using Low level input:
Set the switch to position ”Low / Level”
If the switch is set to wrong
position, the amplifier still
works, but the risk for
disturbancesor distortion
increases.
Input and controls
5
Input Level control ch. A/B/C (Level)
Subsonic filter ch. C
The Subsonic filter blocks the very
deepest frequenciesfromreachingthe
subwoofers. Thefilter crossover is 25
Hz and can be disconnected.
Low pass filter ch. C (LPF)
The LPF ( low pass filter ) allow low
frequencies only and blocks higher
frequencies.Atypicalsetting is 60 – 80
Hz.Choosethe settingthat soundsbest
in your car.
Phase control ch. C (PHASE)
The phase control can be set
continuously from 0 - 180 degrees. This
is very useful when you want to adjust
thebasssoundforbestfrontstageimage.
Start on 0 and turn the control slowly
clockwise until you experience the bass
sound coming from the front.
You may have to change the polarity of
the speaker connection to get the best
result.
HighInput White :A ch.+
White/black :A ch.-
Grey/black :B ch.-
Grey :B ch.+
Input Wiring
Inputsmaybe low level from the RCA output of the car
stereo or high level from the car stereo speaker
output.Low level = RCA is to prefer for the best sound
quality.
CAT31
Subsonic
Off On
LPF
50Hz 120Hz
The input level control, 5V – 0,25 V,
matches the output of your radio to the
input of the amplifier. After installation
is complete, make sure the input of the
amplifier is turned down all the way
(counter-clockwise at 5V ). Play a tape
or CD, make sure all bass or treble
settings or equalizer are flat, and turn
the volume of the radio up until you
just start to hear distortion. Turn the
volume control down just a bit. On the
amplifierincrease theinput levelcontrol
(clockwise or to the right ) until you just
start to hear distortion, then back the
level control just a bit. Now your radio
andamplifier levels are matched.
Level
5 V 0,25 V
Phase
0o180o
Hi / Level
Low / Level

CAT31
Testing
Before you finish the installation, you should do the
following tests to make sure the wiring is correct
andeverything is operating properly.
Test power wiring
1. Turn on the head unit but do not turn up the
volume.The amplifier power light should
come on. If not, check the remote and +24
volt wires.Also check the ground
connection.
2. Turn up the head units volume slightly. All
speakers should operate. if not, check
wiring connectionsatamplifierand
speakers.
Reconnect Battery
Whenwiringiscomplete,
reconnect the battery
negativeterminal.
6
Connection of front speakers
One or two
subwoofers to
the sub channel
(C).
You can connect
two 4 ohm sub-
woofers on the
sub channel
without any risk
foroverload.
Parallel input
Parallel
Input
Off PC
In position PC the signal is internally
connected from input A/B to the input
for channel C. A single RCA cable is
enough to feed all channels. In OFF-
position you must use dual signal
cables or Y-splits.
With the HPF-filter in OFF posi-
tion the amplifier allows the
speakers to play fullrange.
If you for some reason want to
limit the low bass reproduction
switch on the HPF-filter. The
typical setting is then around 60
– 80 Hz.
HPF
Off On
50Hz 220Hz
15Hz 500Hz
High pass filter ch. A/B (HPF)
Two fullrange speakers
connected to ch. A / B.
CAT31canhandlespea-
ker loads down to 1 ohm
per channel. You can
connect four 4 ohm
speakers in parallel on
eachchannel.
+ + C CH - -
Connection of subwoofers
Filter settings ch. C
The subsonic filter takes away the very deepest
frequencies. Turn on the subsonic filter if you want
to remove these frequencis.
The LPF will allow low frequencies only and blocks
higher frequencies.Atypical setting is 70 – 100 Hz.
The phase control can be set continuously from 0 -
180 degrees. This is very useful when you want to
adjust the bass sound for best front stage image.
Starton0 and turn the control slowly clockwise until
you experience the bass sound coming from the
front. If you dont get the result you want, also try to
phasereverse thesubwoofer connectionsandmake
anew adjustment.
Filter settings ch. A/B
With the HPF-filter in OFF position the amplifier
allowsthespeakerstoplayfullrange.Ifyouforsome
reasonwanttolimitthelowbassreproductionswitch
onthe HPF-filter.Thetypicalsettingis then around
60 – 80 Hz.
+ 24V

Truck installations / Center channel
speakers
Themaindifferencesbetweena sedan car for perso-
nal use and a truck are:
- 1 the wideness of the car and
- 2 the high noise level in a truck in motion.
This makes it hard for the driver to listen to the right
speaker( if thesteeringwheel is on theleft ) and forthe
passenger to hear the speaker on the drivers side.
Althougha singledrivercan adjustthe balance leftright
to compensate for this, a better solution is to add a
centerchannel speaker / speakers.
Often you use a 4 or preferably a 5.25 inch speaker
positioned at the center of the dashboard. Very often
you use two speakers of reasons we will show later.
One center speaker connects to the left channel, but
often at a lower level compared to the main speaker.
Theother center speaker connectslikewiseto the right
channel. The two speakers together will thus play the
sound of Left + Right.
This will fill in what you can call the gap in the
soundstageofthe earlier installation.
Yourside systemwill hopefullybe good6,5inch coaxes
or two-way systems or even better. A small center
channel speaker of smaller size will have to be feed at
a lower level of volume and if possible through a band
pass filter to limit the frequency response to say 500 -
6000Hz.
You can also use one speaker only, but connect it to
the CAT31 amplifier in the bridge mode way. Thus the
speaker will receive the Left + Right channel.
As this voltage is twice as high as what we feed to the
left or the right speaker, we now must use a voltage
divideror attenuator to bring downthepower to what is
suitable for the speaker.
Connecting two center channel speakers
with bandpass filter
Connecting one center channel speaker
in bridge mode with bandpass filter
It is not necessary to use a bandpass filter, only if you
want to limit the frequency range. The bandpass filter
limits the frequency range from 500 to 6000 Hz.
Onnext page is adrawingif you want tobuildyourown
bandpassfilter.
7
0-20 Ω
15 Watt
+ A-CH - - B-CH +
++
-
-
-
+
12
12
12
12
1234
1234
R = 50 ohm
15 Watt
Center channel
Left + right
Right
Front speaker
Left
Front speaker
Bandpass filter
Left
Center channel Right Center channel
Bandpass filter
+ A-CH - - B-CH +
Left
Front speaker Right
Front speaker
+
-
12
12
12
12
1234
1234
R = 20 ohm
15 Watt
0-20 Ω
15 Watt
++
-
-
-
+
12
12
12
12
1234
1234
R = 20 ohm
15 Watt
0-20 Ω
15 Watt
Thedrawingbelowshow how to connect two center
channel speakers to the CAT 31, through a voltage
dividingcircuit. Usinga potentiometer youcan adjust
the volume from the speaker.
If you want to connect a bandpass filter, do so by
using the filter design suggested on next page.
Thedrawing below showhowto connect onecenter
channel speakers to the CAT 31, through a voltage
dividingcircuit.Usingapotentiometeryoucanadjust
the volume from the speaker.
If you want to connect a bandpass filter, do so by
using the filter design suggested on next page.

Bandpass filter for 500 Hz - 6000 Hz
for a 4 ohm speaker
123
1
2
3
1
2
3
1
2
3
1
2
3
123
123456
1
2345
6
123456
+
-
+0,15 mH air coil 1,75 mH
core coil
4,7 µF50 µF
-
For 2 ohm speakers (two 4 ohm in parallell) or an 8
ohm combination (two 4 ohm in series) chose the
values in this table.
Spkr imp. L1 C1 L2 C2
2 ohm 0,07 mH 10 µF 0,9 mH 100 µF
4 ohm 0,15 mH 4,7 µF 1,75 mH 50 µF
8 ohm 0,3 mH 2,2 µF 3,5 mH 25 µF
You can of course use two bandpass filters and
connect one filter between the amplifier and each
speaker.
8
Connecting two center channel speakers
to rear output of the car stereo head unit
Connecting one center channel speaker
in bridge mode to rear output of car
stereo head unit.
FRONT REAR
L R L R
+ - + - + - + -
CarStereo
RCA leads to
CAT 31 amplifier
+
-
FromL+andR-
1 x 15 Watt
centerchannel
fill in left + right
If you don´t have any attenuators or bandpass filters
available, there is a simple connection using the built
in power of a 2 x 20 Watt or 4 x 20 Watt head unit.
Althoughmost headunits arereferedto as 2x35 Watts
ormore, the true RMS power is normally 2 x 14 Wattin
a four ohm load. The reason you buy an amplifier is to
raisetheavailablepower to2 x75Watt,roughly5 times
more. However as a sort of fill in the built in power can
serve, as long as you do not push the car stereo into
distortion.
Thecenterchannel speakers can be connected to say
rear left and to rear right.
Using your fader control between front and rear you
can adjust the volume of the center speakers in
comparisontothemainspeakersfeedfromtheamplifier
Thecenter channelspeakers will produce2 x15Watts.
Shouldyouhave onecenter speakeronly,youcan even
connect it as above, but to rear left plus and to rear
rightminus. This way the speaker will reproduce Left +
Right channel but only with 1 x 15 Watt.
2 x 15 Watt
centerchannel
fill in
RCA leads to
CAT 31 amplifier
Observe
polarity
CarStereo
+
+
-
-
FRONT REAR
L R L R
+ - + - + - + -
Center channel from car stereo head unit

NOISE PROBLEMS
WHININGNOISEVARYING WITH ENGINE
REVOLUTIONS:
Do this:
1. Rewirethepowersupply(24V)tosource
unit direct from battery.
2. Rewireground wire from source unit to
clean position on chassis.
3. Check all power connections to ensure that
they are clean and tight.
4. Check quality of system ground connection.
5. Install a Power Cap capacitor. This can be
helpful against most noise problems.
CONSTANT WHINING NOISE:
Do this:
1. Ensure that all equipment has a common
groundpoint.
2. Check quality of earth strap connection from
battery negative terminal to chassis.
3. Disconnect signal cables from amplifier to
see if noise disappears. If so the leads are
picking up noise. Test this by laying a new
cable over the seats and reconnecting to the
amplifier. If the noise does not return, re-
routeoriginal cable away from source of
interference.
If noise remains regardless of cable position,
try to use so called Quasi-balanced signal
cables. DLS PRO or ULTIMATE cables are
quasibalanced.
SPEAKER POLARITY CHECK.
All speakers in a car audio system should be
connectedin phase (the same polarity).Allspeaker
cones must move in the same direction. Out of
phase speakers will cause a lack of bass, and a
poorstereo soundstage.
Checking polarity:
Hold the - connection of the speaker wire to the -
terminal of a 1,5 Volt flashlight battery. Tap the +
wireon to the + terminal of the battery,and observe
the movement of the cone. The cone should move
outwards when the wire touches the battery, and
inwards when the battery is removed. If it is the
otherway around, thespeakerhas been connected
backwards and it must be removed and connected
correctly.
If your system also has a subwoofer connected
through a passive 6 or 12 dB crossover, try to
connect this with various polarity and judge what
soundsbest. The phase shift in passive crossovers
sometimes makes it necessary to change polarity.
+
-
+
-
Batteri
1,5 Volt
Professional Tip:Professional Tip:
Professional Tip: Professional Tip:
Installing in trunk
When installing the amplifier in the trunk, run the
powerwiresalongthesamepathas theothervehicle
wiring.Manycars haveinsulatedchannelsforwiring.
you will have to remove the door sill trim and the
carpet.
Securing wires
Usewire ties to bundle together when possible.
(Butneverbundlespeaker wires or signal cables
togetherwith power wires.
Professional Tip:
Professional Tip:
Speaker and power wires
Do not run speaker and power wires next to each
other. Power wires can generate a ”siren” sound in
the speakers. Runs speaker and power wires on
opposite sides of the vehicle.
Crimp connections
Purchasecrimp connectors and crimping tool.
Connectorsare color coded.
1. Strip 1/4 inch (6 mm) of insulation from the wire.
2. Insert into connector
3. Crimp tightly
9
CAT31

Specifications
DLS CLASSIC CAT31 - 24 Volt
Numberof channels 3
Stereo Channels: Ch A & B
RMS power out in 4 ohm ( 0,1% THD) 2 x 75 Watt
RMS power out in 2 ohm ( 0,1% THD) 2 x 145 Watt
RMS power out in 1 ohm ( 0,5% THD) 2 x 210 Watt
RMSpowerout in4 ohmbridgedmode 1 x 280 Watt
Filters high pass 50 – 150 Hz
MonoChannel: ChC
RMS power out in 4 ohm 1 x 170 Watt
RMS power out in 2 ohm 1 x 280 Watt
Filter subsonic 24 dB slope 25 Hz fixed*
* can be switched in or out
Filter low pass 24dB slope 50 – 120 Hz
Phasecontrolmono channel continuous var. 0 – 180 degrees
All above output power ratings at 28V DC
Inputimpedance, low level (RCA ) > 10 kohm
Inputimpedance,high level 100 ohm
Input sensitivity, low level ( RCA ) 0,25 – 5 V
Frequencyrange 10 Hz – 35kHz
Signalto noise ratio,A-weighted > 90 dB
Power consumption, idle / max 0,7 A/ 40 A
Fuses 2 x 20 A
Dimensions,mm 67 x 350 x 250
Dimensions,inches 2,63 x 13,78 x 9,84
Weight 4,7 kg / 10,36 lb
DCvoltage range 24 – 30 V DC
Remotevoltage range 12 – 30 V DC
Wefollowa policyofcontinuous
advancement in development.
For this reason all or part of
specifications&designsmaybe
changedwithout prior notice.
10

DLS Svenska AB
P.O Box 13029
SE-40251 Göteborg
Tel: [phone]
Fax: [phone]
E-mail: [email protected]
www.dls.se