CARVIN DCM1204 Operating Manual Download Page 2

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DCM1000

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FRONT & REAR PANEL CONTROLS

WARNING

This product produces high
sound pressure levels that
could damage your hearing.
Use with caution.

FRONT PANEL

1. MOUNTING

Sturdy one piece 12 gauge steel face plate accommodates standard 19” rack installation. The rack mount-

ing holes are designed on ISO standard spacing. Four 10-32 x .5” phillips machine screws are normally
used to secure the amp. Rear support brackets are not required.

2. POWER SWITCH

Check the power amp connections and verify the AC line power source before engaging the POWER

switch. The yellow LED unmistakably indicates that all circuits are properly powered up. Yellow is used
so the operator can see the red indicators (clipping or protect) from a distance.

3. CHANNEL LEVEL CONTROL

A precision input LEVEL attenuate is used to adjust the volume levels. To deliver the amps maximum power

without reducing the headroom of the signal source, the level controls should be turned full on.

4. CHANNEL SIGNAL INDICATOR

The green SIGNAL LED indicators will flash when there is a signal passing to your speakers (-30dBµ). This

lets you know when the amp is passing a signal to your rear speaker connectors.

5. CHANNEL CLIP INDICATOR

The red CLIP LED indicators will flash when each channel has reached its maximum output. Occasional

flashing caused by lower bass frequencies is OK. However, consistent flashing caused from higher frequencies
may damage high frequency drivers (excessive distortion). This does not cause damage to the amp.

6. COOLING VENTS/FAN

Upon rack installation, the rear of the amp must be fully exposed to room temperature air. The sur-

rounding air should not be warmer than 120° or the thermal protection could active the PROTECT LED.
The front cooling vents are not to be restricted from exhausting the warm air.

7. PROTECT LED INDICATOR

The red PROTECT LED provides the operator with information about the status of the amplifier. The

PROTECT LED can come on under 3 different conditions (when this happens both channels are muted
by disconnecting the output speaker relays protecting your speakers);

1) During power-up, the amplifier stays in a muted state for approx. 3 sec until it determines that

everything is functioning normally (no output shorts or over temp conditions).

2) All four channels are muted when the output load draws excessive current or a direct short is detected

caused by a shorted speaker cable or speaker system. Reset this condition by turning the amp off
for two seconds and then on again. Check for shorted cables and the total speaker system imped-
ance connected to each channel (4 ohms is the minimum per ch or 8 ohms BRIDGED).

3) Overheating is usually determined when the amp stops in the middle of a performance and the

PROTECT LED comes on. If this is the cause, leave the amp on for the fan to cool the amp down.
The amp will automatically reset within 1 to 3 minutes and the PROTECT LED will turn off when
ready. Check for the following conditions; a) The rear intake air is restricted, b) The intake air is
extremely warm, c) The front exhaust vents are restricted, or d) Excessive speaker load (try other
speakers or remove speakers if you have more than one connected to each channel). Again, the
minimum impedance is 4 ohms per ch or 8 ohms BRIDGED)

REAR PANEL

8. Balanced 1/4” PHONE JACK INPUTs

This stereo 1/4” phone jack is designed to receive either balanced or unbalanced input signals. Balanced

signals coming into this jack should be wired with the connector’s tip going to and the connector’s

ring to signal -. The connector’s sleeve is tied to ground through the GROUND LIFT switch.

9. PARALLEL OR “Y” INPUT SWITCHES 1-2, 3-4

The rear PARALLEL switches allow you to drive two channels from one input. All signals from ch 1 or

ch 2 will be available on channels 1&2, likewise channels 3&4. This eliminates Y adapter. This feature
is also used to “daisy chain” one piece of equipment to another. Just plug into the unused INPUT 1/4”
and it will become an output for other equipment.

10. INPUT GROUND LIFT

Many times sound systems are connected in such a manner to cause a grounded loop with the inputs

which result in audible hum. The input GND LIFT (1/4”) switch on the rear panel will help eliminate this
problem. If not, another way to eliminate ground loops is to install Carvin’s MTF55 “Ground Lifter” between
the amplifier input and the signal source. This isolates the input ground from the AC power ground.

11. LIMITERS

To activate the LIMITERS, engage the rear limiter switch. The built-in optio isolator limiters are recommended

to hold down peaks that could cause early distortion. These limiters will help to rise the average power so
that you can get more output from each channel. To check the effectiveness of the limiters when the chan-
nel starts to distort (under the amps full output), engage the limiters and hear the reduction of the distortion.
If the distortion stops, you can turn the channel up for more power. The lower bass frequencies are most
affected. WARNING: Do not check in an environment where the sound level could damage your ears!

12. SPEAKER 1/4” OUTPUTS

The standard 1/4” SPEAKER jacks are offered for lower power applications. Speakon™ connectors are

provided for high power application. Secure the Speakon™ connection by turning to the right. The center
Speakon™ is for Bridge only. Turn the amp off before connecting your speakers.

13. SPEAKER OUTPUTS SPEAKON™

Speakon™ connectors are provided for high power application. Secure the Speakon™ connection by turn-
ing to the right. The center Speakon™ is for Bridge only. The wiring of the three Speakon™ connectors
are:

First connector from the left:

Channel 1 pin 1+ pos. Pin 1- neg.
Channel 2 pin 2+ pos. Pin 2- neg.

Center connector: (for bridging only)

CH 2-3 bridge pin 1+ pos. Pin 1- neg.
not used pin 2+ Pin 2-

Third connector from the left:

Channel 4 pin 1+ pos. Pin 1- neg.
Channel 3 pin 2+ pos. Pin 2- neg.

This arrangement allows biamp connections with the out side Twist-Lokconnectors (see stereo biamping) and
stereo plus a high power bridged subwoofer with all three Twist-Lok connectors (see stereo plus subwoofer).

14. BRIDGE MODE—

25V/70V DISTRIBUTION SYSTEMS

The “DCM” Series can be operated in bridge mode if you require a 25V / 70V distribution speaker system

or a high powered mono (single channel) amp. With your amp off, push “IN” the rear (recessed) BRIDGE
switch after you have made your connections with the bridge Speakon™. The 1/4” speaker jacks can not be
used at the same time! Select carefully or damage may result to your speakers. This is why the switch has
been recessed. The INPUT and LEVEL is handled by channel 2. Channel 3 is non-operational. The minimum
speaker impedance is 8 ohms or a 25V distribution line. CAUTION: The power developed by bridging your
amp can destroy most speaker systems! Make sure your speaker(s) are of the proper impedance and power
handling.

15. AC POWER

Your amp is designed to run on either 120V 60 Hz or 230V 50Hz depending on the model purchased.

The voltage range for 120V model is 95V to 132V and for 230V model it is 195V to 253V. The rear heavy-
duty AC receptacle will accept a standard grounded AC cord that is designed your country. Be sure to
check your power source before plugging into a grounded (3 prong) outlet. Never defeat the grounded
connection or electrocution may result! Firmly push the AC cord all the way into its receptacle. In the
case of a blown fuse; unplug the amp, remove the lid and replace the 20 amp fuse located in the back
corner above where the AC cord connects to the circuit board.

Note: Each amp will require a dedicated 20 amp circuit if you are driving the amp to its full output. There
will be a sustained loss of power if the AC voltage is below the rated 120V or 230/240V so be sure you
use a heavy gauge power cable (and source).

(Recessed)