Fiber optic decoder | Mercedes E/CLS/S/SL/SLK/CL | 2000 to 2004

The CTX-3306 Fiber Optic Decoder makes it possible to neatly and effortlessly connect an aftermarket Android car radio to the original Bose or Harman Kardon sound system in your Mercedes from model years 2000 to 2005. Thanks to this decoder, which uses the original fiber optic connection, you do not need to run cables through the car to the trunk.

This allows you to retain the original amplifier and speakers while still being able to enjoy the latest infotainment features of an aftermarket car radio.

This fiber optic decoder is suitable for:

Mercedes E-Class (W210) – 2000 to 2002
Mercedes S-Class (W220) – 2000 to 2003
Mercedes SL-Class (R230) – 2003 to 2004
Mercedes SLK-Class (R171) – 2000 to 2004 (transition year)
Mercedes C-Class (W203) – 2001 to 2004
Mercedes CL-Class (C215) – 2000 to 2003
Mercedes CLK-Class (C208 / C209) – 2001 to 2004

✅ Only suitable for vehicles with Bose or Harman Kardon audio via fiber optics (MOST system)

How does the car radio Fiber Optic Decoder work?

The CTX-3306 converts the digital audio signal running from the amplifier to the speakers via the fiber optic cable into a usable signal for an aftermarket radio. This keeps the original speakers and amplifier fully active, but replaces the audio source with your new car radio.

This allows you to seamlessly switch to Android, CarPlay, or other modern systems without making any changes to the original wiring.

Connection & Installation

You can usually recognize the fiber optic connection by the orange cable behind the original factory radio. The CTX-3306 is placed behind the aftermarket radio and connected directly to the car radio and the orange fiber cable.

The installation is technically simple but requires basic knowledge of automotive systems. The decoder comes with an installation manual so you can perform the mounting correctly.

This product is only required in combination with Bose or Harman Kardon. Do you not have an original premium audio system? Then the CTX-3306 is not necessary.

Frequently Asked Questions (FAQ)

Do all original speakers work with the CTX-3306?
Yes, all original speakers remain fully functional via the fiber optic channel.

Can I control each speaker individually?
No. Control is routed via one shared fiber optic channel. Individual speaker control per channel is not possible.

Is the original amplifier retained?
Yes, the original Bose or Harman Kardon amplifier remains fully active.

Do I need to run cables to the trunk?
No, that is not necessary. The connection is made entirely behind the radio via the fiber optic link.

Is the decoder suitable for every Mercedes?
No, only for the listed models with Bose or Harman Kardon and a MOST fiber optic system.

Will my original CD changer still work after replacing the radio?
No. If you have an original CD changer supplied by Mercedes from the factory, it will no longer function after replacing the original radio.

Can I continue to use the original radio antennas?
No, it is not possible to reconnect the original radio antennas. In that case, we recommend using free digital radio via CarPlay or Android Auto.

Can I connect any aftermarket car radio with this?
Yes, the CTX-3306 is suitable for all common aftermarket Android car radios with an RCA audio output.

Important to know

This item is only necessary if your Mercedes is equipped with an original Bose or Harman Kardon audio system with fiber optics (MOST). Without this system, the decoder is not needed and a standard connection works via speaker wires.