Here you can see how I modified an old Pioneer Stereo Receiver. I mounted a Rasperry Pi to have the MusicBox functionality. The Pi is powered by the build in power supply. The original AUX input is used to transfer the sound. Additionally I added a Startup / Shutdown button and the GPIO status LED.

• Raspberry Pi Model 1 B+ with USB power and Audio out soldered
  • PP1 ... +5V
  • PP3 ... GND
  • PP6 ... Audio GND
  • PP26 ... Audio R
  • PP25 ... Audio L

• Raspberry Pi mounted

• Audio out soldered to AUX input

• Amplifier back side

With this configuration and the MusicBox software installed, the old Amplifier should have modern features to play sound. Unfortunately first tests showed, that it is no good idea to put a WiFi dongle into a metal case. The wireless connection was stable only about 1 to 2 meters in front of the access point. What surprised me was the fact that Bluetooth was working fine.

Therefore I desided to use an external WiFi antenna. I used an USB WLAN stick with antenna, extracted the board, mounted the antenna to the amplifier case and soldered the board to the USB pins of the Raspberry.

Now the Box was ready to rock