CTX-3303 | Optical fiber decoder | Mercedes E-Class w211 | S/SL/SLK/CLK | from 2009

The CTX-3303 Fiber Optic Decoder makes it possible to connect an aftermarket Android head unit to the original Bose or Harman Kardon sound system in your Mercedes in a neat and hassle-free way. Thanks to this decoder, which uses the original fiber optic connection, you do not need to run any cables through the car to the trunk.

This allows you to keep the original amplifier and speakers while still enjoying the latest infotainment features of an aftermarket head unit.

This fiber optic decoder is suitable for:

• Mercedes-Benz CLS (w219) 2009 to 2012
• Mercedes-Benz E-Class (w211) 2009 to 2012
• Mercedes-Benz SL-Class (w230) 2009 to 2012
• Mercedes-Benz SLK-Class (w171) 2009 to 2012
• Mercedes-Benz CLK-Class (w209) 2005 to 2009
• Mercedes-Benz B-Class (w245) 2009 to 2011

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

How does the head unit Fiber Optic decoder work?

The CTX-3302 converts the digital audio signal that runs from the amplifier to the speakers via the fiber optic cable into a usable signal for an aftermarket radio. As a result, the original speakers and amplifier remain fully active, but the audio source is replaced by your new head unit.

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

Connection & Installation

The fiber optic connection can usually be identified by the orange cable behind the original factory radio. The CTX-3302 is placed behind the aftermarket radio and connected directly to the head unit and the orange fiber cable. There is no need to run cables to the amplifier in the trunk.

Installation is technically straightforward, but requires basic knowledge of car systems. The decoder comes with clear labels for the connections.

This product is only required in combination with Bose or Harman Kardon. Do you not have an original premium audio system? Then the CTX-3302 is not necessary.

Frequently Asked Questions (FAQ)

Do all original speakers work with the CTX-3302?
Yes, all original speakers remain fully functional via the fiber optic channel.

Can I control each speaker individually?
No. The system is controlled via a single 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 the 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 keep using the original radio antennas?
No, it is not possible to reconnect the original radio antennas to an aftermarket head unit. In that case, we recommend using digital radio via CarPlay or Android Auto.

Can I connect any aftermarket radio with this?
Yes, the CTX-3303 is suitable for all common aftermarket Android head units with an RCA audio output.