> DVB2000 > Digital Audio Output 

On this page you will find a description on how to add digital output hardware to your dBox / Mediamaster. This article is based on the page of Manfred Boehmel (the original page went offline).

The "Kids, dont do this at home"-Message:
Warning ! Soldering around in your box might destroy your box. 
Unplug your box before opening it. You do this at your own risk ! 

1. What you need...

  • Optical transmitter:
    TOTX173(print) or TOTX178(print) or TOTX176(box)

    The TOTX176 has a plastic hole for panel mounting, the TOTX173 is the print version. Instead of the TOTX176 you can use the cheaper TOTX178, but the optic wire should not exceed 5m - the both other ones drive up to 10 meters. The connection is much easier, but don't forget the 100nF capacitor between GND and +5V at the TOTX178. By the way, the name TOTX derives from Toshiba/Toslink and Transmitter (there is also a TORX, the receiver).

  • 10F capacitor

  • 100nF capacitor (not needed for TOTX173)

  • 8k2 Ohms resistor

2. Build the Circuit board...









3. Connect your board to the Box digital output











Be careful not to damage the smd capacitor or the audio decoder due extreme heat or static electricity. Ensure that you did not short multiple pins of the crystal chip.

If everything is ok, you can reconnect your cables and power on the box. You should see a red light inside the TOTX now.

4. Reconfigure the Software 

Upload the latest DVB2000 firmware into your Box. In Menu-8-9 you have to Enable AC3. Then you have to set all your channels to AutoPid:ON.

Then.... go to Menu-9-4 and enter:
XMTCN: 0168

For a CS4922 and a Harman Kardon AVR35RDS these settings work fine. For other receivers you might need other XMTCS values.

Sometimes you have to reboot the Box or reset the DSP (Menu-9-0) to produce a correct audio signal. 

5. Troubleshooting

On of the most frequent problems is the message "CL sucks". This Message appears if you produced a short-circuit on the I2C bus of the box. In this case, please check the soldering points on the crystal chip. If you dont see a red light inside the TOTX, you either already burned the TOTX or the power supply cables are not connected correctly.


Copyright 2010 GkWare e.K.