4CH CV DMX-PWM Decoder LT-840-6A

Model: LT-840-6A/D4-L Review stars 5.0 (1 Reviews) Various options in stock
PriceA$67.51 A$43.1036% off
Select Specifications:
Note:
Qty: -+
❓ Ask a question about this item — an engineer replies within 12 hours
Free shipping over $299Ships via DHL / UPSWarranty covered

Accept the project customization, please contact us for commercial offers and technical support.

  • Product Information
  • Reviews
  • Downloads
  • Images
  • LED Strip Lights Guide

Product Information

This is the Ltech D4-L, the official replacement and upgrade for the legacy LT-840-6A model. The D4-L is a professional-grade 4-channel constant voltage (CV) DMX512 decoder engineered for precise, flicker-free PWM dimming of LED lighting. It translates standard DMX512 signals into the PWM signals required to drive single color, tunable white, RGB, or RGBW LED strip lights. A key enhancement is the inclusion of RDM (Remote Device Management), which allows for bi-directional communication with a compatible DMX master controller. This feature dramatically simplifies installation by enabling remote addressing and configuration. With a robust 6A per channel output, multiple interface options (XLR-3, RJ45, Green Terminal), and a wide 5-24V DC input range, the D4-L provides the flexibility and power needed for demanding architectural, stage, and commercial lighting projects.

Front view of the D4-L DMX/RDM decoder showing ports and DIP switch.
Wiring diagram illustrating DMX console and LED strip connections.

Key Features

Advanced RDM Support

Enables bi-directional communication for remote DMX address writing and configuration, saving significant setup time on large projects.

Versatile 4-Channel Output

Provides precise 0-100% PWM dimming for RGBW, RGB, tunable white, or up to four independent single-color LED lighting zones.

High Load Capacity

Delivers a strong 6A per channel (max 24A total), capable of powering up to 576W of lighting at 24V.

Multiple DMX Interfaces

Equipped with 3-pin XLR, RJ45, and green screw terminal connections for maximum compatibility and installation flexibility.

Wide Voltage Compatibility

Operates on a broad DC 5V to 24V input range, making it suitable for virtually all constant voltage LED strip lights.

Manual & Standalone Modes

Features a 10-pin DIP switch for manual DMX addressing and includes built-in self-testing modes for easy diagnostics without a console.

Technical Highlights

  • Features integrated signal amplification on the green terminal DMX port, ensuring signal integrity in large installations.
  • Supports flexible channel configuration: 4 channels at 6A each or 3 channels at 8A each.
  • Equipped with short-circuit and over-current protection for enhanced system safety and longevity.
  • Smooth, flicker-free dimming from 0-100% suitable for on-camera applications.

Product Specifications

ParameterDetails
ModelD4-L (Replaces LT-840-6A)
Input SignalDMX512, RDM
Input Voltage5~24V DC
Max Current Load6A × 4CH (Max 24A Total)
Alternate Load Config8A × 3CH
Max Output Power120W (5V) / 288W (12V) / 576W (24V)
Output TypeConstant Voltage (CV) PWM
DMX512 Sockets3-pin XLR, RJ45, Green Terminal
Dimming Range0~100%
DMX Address SettingDIP Switch / RDM
ProtectionsShort circuit, Over-current
Working Temperature-25℃ ~ 55℃
Dimensions (L×W×H)156 × 78 × 40 mm
Package Size (L×W×H)180 × 82 × 48 mm
Gross Weight445g
Dimensional drawing of the D4-L decoder.

Application Scenarios

Architectural and Stage Lighting Ideal for dynamic control of building facades, cove lighting, and landscape features. Its reliable DMX decoding and high power output are perfect for professional stage productions and event lighting where precise scene control is essential.
Commercial and Hospitality Spaces Powers and controls ambient and accent lighting in restaurants, bars, retail stores, and hotels. Create immersive brand experiences and mood lighting with smooth transitions and vibrant colors, all managed through a central DMX system.
Themed Entertainment and Exhibits Provides the robust control needed for interactive museum exhibits, escape rooms, and themed attractions. The D4-L can drive multiple fixtures to create complex, synchronized lighting effects that enhance the user experience.

How to Control & Use This DMX Decoder

  1. Mount the decoder in a dry, well-ventilated location, ensuring adequate space for heat dissipation.
  2. Connect your constant voltage DC LED power supply to the 'Power Input' terminals. Ensure the supply voltage (5V, 12V, or 24V) matches the voltage of your LED strips.
  3. Wire your LED strips to the 'Connection Socket' output terminals. Connect the common anode wire to 'V+' and the individual color wires (R, G, B, W) to the corresponding CH1-CH4 terminals.
  4. Connect your DMX signal source to one of the DMX IN ports (XLR-3, RJ45, or Green Terminal). To connect multiple decoders, use a DMX cable to daisy-chain from the DMX OUT port of one decoder to the DMX IN of the next.
  5. Set the DMX starting address. For remote setup, use an RDM-enabled master controller. For manual addressing, ensure DIP switch #10 is OFF, then use switches #1-9 to set the binary address value. This decoder occupies 4 DMX addresses.
  6. For standalone testing without a DMX console, engage the self-testing mode by turning DIP switch #10 ON. Use switches #1-9 to select from built-in static colors and dynamic chase effects.
⚠ Precautions
  • This product is for use in dry, indoor locations only. If installed outdoors, it must be placed in a waterproof enclosure.
  • Ensure the total power consumption of your connected LED strips does not exceed the decoder's maximum output power (e.g., 576W at 24V).
  • Always verify that the input voltage from your power supply matches the required voltage of your LED fixtures before powering on.
  • For installations with more than 32 decoders or long signal lines, a DMX signal amplifier may be required.

What's in the Box

  • ✓1x D4-L DMX/RDM 4CH CV Decoder
  • ✓1x User Manual

⇩ Downloads & Documents

PDFD4-L

PDFLT-840-6A

Frequently Asked Questions

Q: What is the difference between the old LT-840-6A and this D4-L model?

A:The D4-L is the new, upgraded model that replaces the LT-840-6A. It adds RDM (Remote Device Management) support for easier setup and has an updated operating temperature range. We ship the D4-L for all orders of this product.

Q: What is a DMX controller for LED lights and what does RDM do?

A:A DMX decoder like the D4-L translates signals from a DMX lighting console into a format that controls the brightness and color of LED strips. RDM allows the DMX console to communicate back to the decoder, enabling remote addressing and status monitoring, which greatly simplifies installation.

Q: How do I set the DMX address manually with the DIP switches?

A:First, ensure DIP switch #10 is in the OFF position. Then, use switches #1-9 to set the starting address in binary code. Each switch has a value (1, 2, 4, 8, etc.); add the values of the switches in the ON position to get your address. Please see the dmx512 decoder manual in the Downloads section for a complete chart.

Q: Can this decoder control RGBW LED strip lights?

A:Yes, absolutely. The four channels are perfectly suited for controlling the Red, Green, Blue, and White channels of standard constant voltage RGBW LED strip lights.

Q: What kind of power supply is required for this decoder?

A:You will need a constant voltage LED power supply with an output voltage that matches your LED strips (e.g., 12V or 24V). The power supply's wattage rating must be high enough to support the total load of all connected strips.

Q: Can I test my lights with this decoder if I don't have a DMX console yet?

A:Yes. The D4-L has a built-in self-testing mode. By setting DIP switch #10 to the ON position, you can use the other switches to activate various static colors and dynamic color-changing patterns for testing and troubleshooting.

Q: How many DMX addresses does this unit use?

A:This is a 4-channel decoder, so it will occupy four consecutive DMX addresses, starting with the address you set.

 

Reviews

Customer Experience

Your feedback is important to us! Share your thoughts and photos with other customers.

C
09/08/2026

Really impressed with the customer service

I ordered a few of the LT-840-6A decoders, not realizing the model had been updated. A little while later I got a very helpful email from Violet checking to make sure the new D4-L model would work for my needs before shipping. She was super proactive and it was great that she took the time to confirm with me, especially given the time difference. It probably saved me a huge headache down the line. The decoders arrived here in the US faster than I expected and are working great for my project. That kind of service is what keeps you coming back. Thanks again Violet!

Downloads

Files for LT-840-6A/D4-L
Need CAD drawings, IES files or a signed test report? Contact our engineers and quote the model number.

Images

These images were taken with Canon EOS 5D Mark IV and the studio light source is provided by Ra 98's full spectrum LED strip to realistically reproduce the colors of the item itself. All copyrights are created by the superlightingled team, please feel free to browse and download if you are a registered user!

 4CH CV DMX-PWM Decoder LT-840-6A 4CH CV DMX-PWM Decoder LT-840-6A

LED Strip Lights Guide

Here you can learn anything about LED strip lights — pick the topic you are interested in to go deeper. We cover LED strip lights, power supplies, controllers, accessories, and how to connect LED strip lights.  You can also watch our demo videos.


Led strip lights

►Everything you need to know before you buying led strip lights

Top 6 Considerations Before Buying LED Strip Lights

1. Where do I want to place the LED strip lights? Indoor or outdoor?

• What are waterproof led strip lights?

• How to cut and connect waterproof led strip lights?

2. How much LED brightness do I need?

3. The working voltage is available?

• 5V VS 12V VS 24V led strips

• AC VS DC 

4. How long is the LED strip light suitable for my project?

5. Do I need an LED light controller to adjust the LED color and brightness?

6. How to power the LED strip lights?

What are led strip lights?

1. How do led strip lights work?

2. How long can you run an LED strip?

3. How long do LED strip lights last?

Is it worth getting led strip lights?  

1. Do LED strip lights use a lot of electricity?

2. Why are LED lights energy efficient?

3. Are LED Strip Lights sustainable?

4. What are the pron and cons of led strip lights?

5. Precautions for led strip lights

Are led strip lights safe?

1. Do LED strip lights overheat?

2. How do you stop LED strips from overheating?

3. Can LED strips catch fire?

4. Is it safe to sleep with LED strip lights on?  

What are the types of led strip lights? Flexible led strip lights VS rigid led strip lights -

1. What are flexible led strip lights?

2. What are rigid led strip lights?

3. What happens if you bend LED strip lights?

4. What is the difference between flexible led strips and rigid led strips?

How to cut led light strips? 

1. Can you cut led light strips? 

2. What happens if you cut an led strip?

3. How to cut led strip lights?

4. How to connect RGB color changing led strip lights with a connector?

5. How to know what your led strip light is?

How to choose the correct SMD led for your strip?

Which is the brightest SMD LED?

What does SMD 5050 mean?

How many lumens is a 5050 SMD LED?

How to know what type of LED strip?

What is the difference between 2835 and 5050 LED?

 

►COB led strip light

What is COB led strip light?

1. What is COB?

2. What is the COB production process? 

3. Different types of COB strip lights

4. What is the difference between COB and SMD led strip lights?

5. What is the difference between COB and LED?

6. Are COB led strips better?

7. How to cut and connect COB led strips?

8. How to install COB led strip lights?

9. Can COB light strips use aluminum channels?

10. Why choose superlightingled?

 

►Led neon lights

What are led neon lights?

1. What is led neon light?

2. What are neon led lights used for?

3. Are led neon lights good?

4. How to choose led neon rope lights?

5. Are led neon ropes use DC or AC?

6. Can you change the light-emitting angle or the luminous way of neon led strip?

7. Silicone Tube VS PVC Tube

How to make led neon lights?

1. How to cut led neon lights

2. Can led neon lights be connected?

3. Easy 7 steps to make led neon lights

4. How to install led neon rope?

 

►Addressable led strip

Ultimate Guide to Choosing the Right Addressable LED Strip

What is an addressable LED strip?

Can you cut addressable LED strips?

How to judge if an LED strip is individually addressable?

How to choose the best DC12V addressable led strips?

How to choose the best DC5V digital led strips?

How to choose the right IC for your project?

Which IC is most commonly used?

How do I know my IC type?

How do I know if my IC is good or bad?

How many types of IC are there?

How to wire addressable led strips?

 

►Color, color temperature, and CRI

The Color Difference Between Warm White 2700K, 3000K, 4000K, 6000K Pure White and 7000K Cool White

1. What is color temperature?

2. What color temperature is right for me?

• 2700K VS 3000K

• How obvious is the difference between 2700K and 3000K?

• Warm White 3000K VS Natural White 4000K VS Daylight White 6000K

• Warm White VS Cool White

3. Enjoy 2700K, 4000K, 6000K

4. Further Reading: How to install Warm White LED light strip?

How to choose the right color for your led strip lights? -

1. How many colors are in LED strip lights? 

2. What do LED light colors mean?

3. Why do white LED light turns to yellow? 

4. Why are your led strip lights not the same color?

5. What is the most relaxing color for LED lights? 

6. What color led lights is best for sleeping?

7. Are led lights bad for your eyes? 

8. Is cool white or warm white better for eyes?

What is color temperature?

1. What is the best color temperature?

2. Does color temperature keep the same as time goes by?

3. What color temperature is best for night?

4. Led strip lights about color temperature,CCT VS RGBW VS RGBCCT;

What is color rendering in​dex?

1. What is CRI in led lights?

2. How to choose the right CRI when buying led strip lights?

3. What is the relationship between CRI and brightness?

4. Is higher CRI better? High CRI VS Low CRI;

5. How to find CRI value? 

 


Led strip light connection

How to connect led strip lights?

1. How to connect led strip lights together?

2. How to connect LED light strips without connectors?

3. How to solder wires to LED strips?

4. How to connect LED strips without soldering?

5. Which one is better between soldering and using a connector?

6. How to connect mutiple led strip lights?

7. How many LED strip lights can you connect?

How to connect led strip to the power supply?

1. Ensuring the working voltage and power first

2. How to hardwire led strip lights?

3. Can I connect multiple LED strips to the same LED power supply?

How to wire led strip lights?

How to wire single color led strip lights?

How to wire tunable white/CCT led strip lights?

How to wire RGB color changing led strip lights?

How to wire RGBW led strips?

How to wire RGBCCT led strip lights?

How to wire addressable led strips?

 


Controller for led strip lights

How to choose led strip light controllers?

1. WIFI controller

2. RF controller

3. IR controller

4. Bluetooth controller

5. Remote control and panel control

6. Single color controller and multi-color controller

7. DMX512 controller

8. SPI controller

9. DALI controller

10. 0/1-10V dimmer

11. Triac series

12. Sonsor series

 


Led power supply

How to calculate power for led strip lights?

4 steps to calculate the power you need

Performance And Reasons Of LED Voltage Drop

How to choose led strip light power supply?

1. Alternating current power supply VS Direct current power supply

2. Constant current power supply VS Constant voltage power supply

3. How to choose the best led power supply for your led strip light?

 


Led strip light installlation

How to install led strip lights? What accessories will be needed?

1. Adhesive installation for IP20 and IP65 led strip lights

2. How to choose the right led tape?

3. Can IP20 and IP65 led strip lights use aluminum profiles?

4. How to use aluminum profiles?

5. Mounted clip installation for IP67 and IP68 light strips

How to install LED sensor stair lights?

Lighting Up Your Stairs With LED Strip Lights Ideas

How to install led strip lights on TV?

How to install led strip lights outdoor?

 


Accessories

How to choose led strip light connectors?

1. Are all LED light strip connectors the same?

2. How do LED strip lights connectors work?

3. What connectors do you need for LED strip lights?

4.  What are the different kinds of LED connectors?

5. How to choose the right connector for your led strip lights?

Ultimate Guide on Aluminum Profile for LED Strip Lighting

1. What are aluminium profiles used for?

2. Why choose aluminum profiles?

3. Different types of LED aluminum profiles

4. LED aluminum profile VS COB LED strips

5. How to install LED aluminum channels?

6. How To Get Ideal Light Diffuser For Your LED Strip?

7. Add Black Aluminum LED Light Diffusers For Your Home Lighting

8. How To Find The Right Aluminum LED Light Strip Diffuser Channel?

 

Customers who bought this product also purchased...

Scroll for more →