Recently, I bought a vintage record player that can also play radio and contains an “aux” port. I added airplay to it so I can play music form my phone wirelessly.
As you might already know, I really enjoy adding wireless technology into devices that were not designed to have it (see How I added WiFi to my coffee machine). Last time I managed to get a great looking record player from the 70s, which can play either a vinyl, the FM radio or get sounds from an input source. This is the part that interests me (the aux source), I’m planning on putting a raspberry pi in the player that will allow me to use the player as an AirPlay source.
The first step is to open the player and see what we’re dealing with.
Find a power source for the Raspberry Pi
The most important part is to get a reliable 5V power source that I can plug into the Raspberry Pi – I do have some DC-DC converters that would allow me to use a power input from roughly 5V to 30V.
Look at that! isn’t it perfect? it’s labelled and everything – looks like it will be easier than expected. I tested the voltage and the 12V line sounds nice and flat. Sounds too good to be true.
Well, it was too good to be true. The line is only activated when the radio FM input source is selected in the player. So it’s kinda useless.
I started probing for DC voltage on different points on the mainboard, and found 24V on a shunt:
I soldered a wire and connected my Pi. Problem is that I was not able to draw enough current from it to get the pi working correctly.
At this point I was running out of options, so I decided to just get the power from the AC plug on the back.
Attempt 3: success!
Using my trusted AC-DC converters, I gave consistent 5V power input for the Pi. finally.
Re-route the aux line to the Raspberry Pi
Bring the raspberry pi!
Fixing up status lights
When I got the player, the two status lights were not working, so I thought I’d replace them with LEDs