CARVIN DCM1540L (01) PDF Document

For your protection, please adhere to the following safety instructions for your CARVIN DCM1540L amplifier:

WATER AND MOISTURE: The appliance should not be used near water (e.g., near a bathtub, washbowl, kitchen sink, laundry tub, in a wet basement, or near a swimming pool). Care should be taken so that objects do not fall and liquids are not spilled into the enclosure through openings.

POWER SOURCES: The product should be connected to a power supply only of the type described in the operating instructions or as marked on the appliance.

GROUNDING OR POLARIZATION: Precautions should be taken so that the grounding or polarization is not defeated.

POWER CORD PROTECTION: Power supply cords should be routed so that they are not likely to be walked on or pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit from the appliance.

SERVICING: The user should not attempt to service the appliance beyond that described in the operating instructions. All other servicing should be referred to qualified service personnel.

FUSING: If your unit is equipped with a fuse receptacle, replace only with the same type fuse. Refer to replacement text on the unit for correct fuse type.

EUROPEAN SAFETY INSTRUCTIONS: The conductors in the AC power cord are colored in accordance with the following code: GREEN & YELLOW – Earth; BROWN – Live; BLUE – Neutral. A molded main plug that has been cut off from the cord is unsafe. NEVER UNDER ANY CIRCUMSTANCES SHOULD YOU INSERT A DAMAGED OR CUT MAIN PLUG INTO A POWER SOCKET.

To maintain your CARVIN DCM1540L, avoid spilling liquids or allowing any other foreign matter inside the unit. The panel of your unit can be wiped from time to time with a dry or slightly damp cloth to remove dust and bring back the new look. As with all professional gear, avoid prolonged use in caustic environments such as salt air. When used in such an environment, be sure the amplifier is adequately protected by a rack, covers, etc.

The minimum speaker impedance for the CARVIN DCM1540L is 4 ohms per channel in stereo mode and 8 ohms in bridged mode.

1. MOUNTING: The amplifier is a standard 19″ rack mount design. It is recommended to use all four mounting holes for stability. Use 10-32″ Philips truss head screws, which are normally included with your equipment rack.

2. POWER SWITCH: This switch turns the amplifier ON or OFF.

3. PROTECT RED LED INDICATOR: The red PROTECT LED provides information about the status of the amplifier. The LED will illuminate under the following conditions:
– During power-up, it will stay on for approx. 3 seconds until it determines everything is functioning normally, then turn off.
– During operation, the PROTECT LED will illuminate if the amplifier experiences overheating, a direct short, or a shorted speaker cable or system. The condition is correctable by turning the amplifier OFF, checking all cables and loads, and then turning it back ON. If the problem persists, it may need servicing.
– The CARVIN DCM1540L’s minimum impedance is 4 ohms per channel or 8 ohms bridged. Overloading (using an impedance below these values) will cause the PROTECT LED to light and can result in reduced performance and possible shutdown. The amp may also get hot.

4. CHANNEL LEVEL CONTROL: A precision 21-step detented level control is used to adjust the volume levels for each channel. The amp’s maximum input sensitivity is achieved at the full clockwise position (+10dB). For multi-speaker systems, the volume levels can be matched to the loudspeakers with different output ratings for a balanced system.

5. SIGNAL LED INDICATOR (40% & 80% OUTPUT): The green SIGNAL LED gives a visual indication of the output signals. The 40% LED will start to flash when there is a low input signal. The 40% and 80% LEDs will illuminate as the output has reached 40% and 80% levels.

6. CLIP LED INDICATOR: The red CLIP LED indicates when each channel has reached its maximum output. Occasional flashing is acceptable. However, consistent flashing/clipping (square wave) will damage speakers and is not recommended.

CHASSIS VENTILATION: Upon rack installation, the rear of the amplifier must be exposed to cool air temperatures. The front cooling vents must not be blocked. Air flows from back to front. The use of internal rack fans to cool the entire rack is advised for total reliability.

7. AC POWER CORD: The CARVIN DCM1540L is designed to auto switch between 120V 60 Hz and 240V 50 Hz. The amp is rated for 15 AMPS at 120V 60 Hz and 8 AMPS at 240V 50 Hz. Check the rear of the unit for the fuse rating. Plug the cord into a grounded 3 prong outlet. Firmly push the cord all the way into the receptacle or the amp will not receive a proper ground. A missing ground may cause hum, shock hazard or damage. This unit has a fuse located within the main chassis near the AC connector on the PC card.

8. CHANNEL INPUTS: The combination balanced inputs will help reduce signal interference and allow longer cable runs from your signal source (mixer). The gain will be 6dB higher using an XLR balanced cable vs a 1/4″ phone plug. For balanced TRS use, Pin 1/sleeve is signal ground, Pin 2/tip is positive balanced signal, Pin 3/ring is negative balanced signal. The 1/4″ TRS jacks are also designed to receive unbalanced input signals via a standard TS 1/4″ phone plug. The amplifier’s XLR inputs are balanced. Balanced signals coming from the mixer should be wired with the common/shield to Pin 1, the positive to Pin 2, and the negative to Pin 3. The GROUND LIFT switch disconnects Pin 1 from the chassis ground.

9. PARALLEL INPUTS: The recessed PARALLEL switch runs both channels together from either input. This eliminates Y adaptors and provides an easy way to run both sides of the amplifier from a single source. Plug into the desired input (TRS or XLR) and it will become the output for other equipment.

10. INPUT GROUND LIFT: This switch will lift the ground (Pin 1) of the XLR in a manner to stop “ground-loops” with other equipment that results in audio hum. If you are using the 1/4″ input, the ground lift switch has no effect.

11. LIMITERS (recessed slide switch): This switch enables the built-in limiters. It is recommended to hold down peaks that could cause clipping. To check the effectiveness of the limiters, run the amplifier to the point where the red CLIP LEDs flash and then engage the limiter. The signal level should be reduced without the clipping. The level control could damage your ears! Limiters can affect the sound if the amplifier has reduced clipping. If you want the full impact of the amplifier, turn the limiters OFF.

12. BRIDGE MODE (recessed slide switch): With your amp turned OFF, slide the recessed BRIDGE MODE switch to the right “BRIDGE” position. The signal is connected to the CH 1 input, and the CH 1 level control will adjust the power. CH 2 is not used for input or level control. The speaker outputs are bridged and the total power will be delivered to a “mono” or single speaker load. The minimum impedance for the CARVIN DCM1540L in bridge mode is 8 ohms.

14. SPEAKER OUTPUTS: The speaker connectors feature a combination of both 1/4″ and Speakon jacks for your power applications connected in parallel with the rear binding posts. Twist-lock the Speakon connector by inserting and turning it to the right to its locked position. The center Speakon jack is for the “Bridge” output and is connected in parallel with the bridged binding posts.

15. SPEAKER BINDING POSTS (red/black terminals): For bare wires (banana connectors), use the rear BINDING POSTS to connect your speakers. Wire sizes up to 7 gauge can be inserted into the post hole. Banana plugs can be used by connecting to the ends of the binding posts. Spacing is standard 3/4″.

16. AC FUSE: The CARVIN DCM1540L has a slow blow fuse rated at 15A for 120V operation or 10A for 240V operation. If the fuse needs replacement, the top cover must be removed.

TS 1/4″ Unbalanced: Tip is Positive (+), Sleeve is Ground.

TRS 1/4″ Balanced: Tip is Positive (+), Ring is Negative (-), Sleeve is Ground.

XLR Connector: Pin 1 is Ground/Shield, Pin 2 is Positive Signal (+), Pin 3 is Negative Signal (-).

Speakon™ Connector Wiring:

Before attaching wires, slip the “Securing Hub” and then the “Cable Clamp” over the cable.

Strip the cable insulation back 3/4″ and tin the wires by soldering them for 1/4″.

The connection configuration is:

• Black (1+) / positive

• White (1-) / negative

• Red (2+) / positive

• Green (2-) / negative

Solder the wires into the contacts or use the provided hex screws.

Stereo Mode (4 ohm minimum per channel):

You can connect one 4-ohm speaker per channel, or two 8-ohm speakers in parallel per channel. Connect the speaker cables from the CH1 and CH2 outputs (Speakon, 1/4″, or binding posts) to their respective speakers. Ensure the total impedance per channel does not go below 4 ohms.

Mixed Impedance Example (4 ohm CH1, 8 ohm CH2):

Connect a 4-ohm speaker (or two 8-ohm speakers in parallel) to the CH1 output. Connect an 8-ohm speaker to the CH2 output. This is a valid configuration as long as each channel’s impedance is at or above the 4-ohm minimum.

Bridged Mono Mode (8 ohm minimum):

1. With the amplifier OFF, set the rear BRIDGE MODE switch to the right (BRIDGE).

2. Connect your audio source to the CH 1 input only.

3. Use the CH 1 level control to adjust the volume. The CH 2 level control is inactive.

4. Connect your single speaker load (minimum 8 ohms) to the bridged outputs. You can use the center Speakon connector or the two red binding posts (+CH1 and +CH2). The positive (+) speaker wire connects to the CH 1 RED binding post, and the negative (-) speaker wire connects to the CH 2 RED binding post.

1) NO SOUND: The amplifier’s PROTECT LED might be on. Turn the amp off, check all connections, speaker cables for shorts, and reduce the load if it is below the minimum impedance, then turn it back on. Check input cables and source signals.

2) SYSTEM HUMS OR BUZZES CONSTANTLY: Try using the rear GROUND LIFT switch. Check for ground loops with other equipment in your setup. Ensure a proper AC ground is provided to the amplifier.

3) NO HIGH-FREQUENCIES: This is often caused by tweeters or midrange drivers being damaged from feedback or too much power.

4) WEAK BASS: This can be caused by speakers being wired out-of-phase. Check your speaker cable connections at both the amplifier and the speaker to ensure polarity is consistent (+ to +, – to -).

5) POOR SOUND (HISS): If your system has hiss, the gain structure might be incorrect. The mixer should be run near its 0dB mark, and the amplifier level controls should be turned down to the desired volume. Running the mixer at very low levels requires you to turn up the amp’s gain, which also raises the noise floor.

6) SPEAKER/AMP KEEPS SHUTTING OFF: The PROTECT LED will likely illuminate. This is often caused by an impedance load lower than the amplifier’s minimum rating (4 ohms/channel stereo, 8 ohms bridged for the DCM1540L). Check your speaker impedance. Overheating can also cause shutdowns; ensure the front and rear vents are not blocked.

7) DEDICATED CIRCUIT/BREAKER TRIPPING: Each CARVIN DCM1540L requires a dedicated circuit breaker for its AC outlet. There will be a high in-rush of current when the amplifier is turned on, especially if it’s connected to a 120V or 220/240V supply. Normally a 20Amp or larger breaker will work. If you plan to run your amplifier at its full power at 4 ohms/channel or 8 ohms bridged, you may need a dedicated circuit.