Philips AD906WT Wireless transmitter

Date: 2025-11-17

Tags: elec teardown audio

Overview

This AD906WT/01 wireless transmitter came with a LX3950W/01 home theater system and was paired to an AD906WA/01 receiver1.

Such wireless transmitters were offered for home theater systems, as a way to connect the rear speakers without long cables going across a room2.

The wireless transmitter was connected to a specific output on the audio player or amplifier, and it was paired to a matching wireless receiver + amplifier that could power two speakers.

Philips LX3950 setup

The sticker specifies that the transmitter operates at 864MHz.

Inside view

This looks like analog RF, pre-dating digital protocols. There are chances this could be re-used.

Philips AD906WT

There are 2 PCBs, a complex one connected to the antenna, and a simpler one that seems to be here for interconnection with the RJ45 cable.

Interface board

This is a 95mm*35mm, dual layer PCB that has 4 JST connectors, and only a few analog components around an dual opamp. Many components are unpopulated.

Interface board

BOM Identification

Item Type Manufacturer, PN
7115 Dual opamp JRC 45603
1100 Connector JST, 2-pin
1130 Connector JST, 4-pin
1120 Connector JST, 8-pin
1121 Connector JST, 2-pin

Connectors pinouts

1100 pinout

  1. +12V input
  2. GND

1110 pinout

  1. ACH1
  2. AGND1
  3. ACH2
  4. AGND2

1120 pinout

  1. ACH1
  2. GND
  3. ACH2
  4. +12V output
  5. GND
  6. GND
  7. SCL
  8. SDA

1121 pinout

  1. SCL
  2. SDA

Testpoints

TP Signal Connection
F001 +12V 1100.1
F002 GND 1100.2
F003 AGND2 1130.4
F004 ACH2 1130.3
F005 AGND1 1130.2
F006 ACH1 1130.1
F007 ? Unpopulated
F008 ? Unpopulated
F009 ACH2 7115.7 -> Opamp output
F010 ACH1 7115.1 -> Opamp output
F011 ACH1 1120.1 -> inductors output
F012 ACH2 1120.3 -> inductors output
F013 GND 1120.2
F014 +12V 1120.4
F015 NC Unpopulated area
F016 NC 1130, unpopulated
F017 NC 1130, unpopulated
F018 NC Unpopulated area
F019 NC Unpopulated area
F020 NC Unpopulated area
F021 NC Unpopulated area
F021 NC Unpopulated area

Board overview

All other signals are directly connected from the RJ45 to the 1120 connector. It looks like this board was intended to be used in similar standalone products, looking at the unpopulated components that include footprints for a power jack, a switch and RCA inputs.

PCB markings

Bottom side: - 3104 133 3001.2 - 3104 137 3003.1 - 3104 137 3004.1 - 3104 137 3010.1 - 2104 (datecode) - 1 94V-0 UL (PCB substrate flammability rating)

Transmitter board

This is a 80mm*65mm, 4-layer PCB that has one JST connector, one antenna, one RF ASIC in a metal shield, 2 opamps, one analog ASIC, one analog multiplexer and one clock generator.

All components seem to be populated.

Transmitter board
Transmitter board

BOM Identification

Item Type Manufacturer, PN
7101 I²C-programmable PLL NXP TSA5060ATS4 4MHz crystal
7110 Oscillator and divider NXP 74HC4060D5 12MHz crystal
7111 8-channel analog switch NXP 74HC4053D6
7112 Audio compressor, AGC Onsemi SA572D7
7113 Dual opamp JRC 40658
7116 Dual opamp JRC 40659
7117 LDO voltage regulator ST L1117

1101 connector pinout

  1. ACH1
  2. GND
  3. ACH2
  4. +12V input
  5. GND
  6. GND
  7. SCL
  8. SDA

PCB markings

RJ45 Cable

  1. ACH2
  2. AGND
  3. ACH1
  4. +12V
  5. GND
  6. GND-shield
  7. SCL
  8. SDA

Conclusion

This doesn’t seem to be usable without its original equipment or without deeper reverse-engineering, due to the fact the PLL needs I²C data to operate.

References

  1. Philips LX3950W/01 specsheet↩︎

  2. Philips LX3950W/01 manual↩︎

  3. JRC 4565 datasheet↩︎

  4. NXP TSA5060ATS datasheet↩︎

  5. Generic CMOS 4060 datasheet↩︎

  6. Generic CMOS 4053 datasheet↩︎

  7. NXP SA572D datasheet↩︎

  8. JRC 4565 datasheet↩︎

  9. JRC 4565 datasheet↩︎

Electronics Électronique puissance semiconducteur semiconductors power Hardware CPE INSA Xavier Bourgeois

Xavier

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