CTX-3301 Fiber Optic Decoder for Mercedes W211 CLS SLK CL

The CTX-3301 Optical Fiber Decoder makes it possible to connect an aftermarket Android car radio to the in a neat and hassle-free manner original Bose or Harman Kardon sound system in your Mercedes of year of construction 2003 to 2008. Thanks to this decoder, which uses the original fiber optic (optical) connection, you don't have to run cables through the car to the trunk.

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

This optical fiber decoder is suitable for:

Mercedes CLS-Class (W219) – 2005 to 2008
Mercedes E-Class (W211) – 2003 to 2008
Mercedes S-Class (W220) – 2004 to 2006
Mercedes SL-Class (W230) – 2005 to 2008
Mercedes SLK-Class (W171) – 2004 to 2008
Mercedes CL-Class (W215) – 2004 to 2006
Mercedes B-Class (W245) – 2005 to 2008

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

How does the car radio fiber optic decoder work?

The CTX-3301 converts the digital audio signal running via fiber optics from the amplifier to the speakers into a usable signal for an aftermarket radio. This allows the original speakers and amplifier to remain fully active, while the audio source is replaced by your new car radio.

This way, you can seamlessly switch to Android, CarPlay, or other modern systems without any modifications to the original wiring.

Connect & Installation

You can usually recognize the fiber optic connection by the orange cable behind the original factory radio. The CTX-3301 It is placed behind the aftermarket radio and connected directly to the car radio and the orange fiber cable. No cables need to be run to the amplifier in the trunk.

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

This product is only needed in combination with Bose or Harman Kardon. Don't have an original premium audio system? Then the CTX-3301 is not necessary.

Frequently Asked Questions (FAQ)

Do all original speakers work with the CTX-3301?
Yes, all original speakers continue to function fully via the fiber optic (optical) channel.

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

Will the original amplifier be kept?
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 connection.

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

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

Can I continue using the original radio antennas?
No, it is not possible to reconnect the original radio antennas to an aftermarket car radio. 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-3301 is compatible with all common aftermarket Android car radios with an RCA audio output.