Look at it shine!

Create a tech filled stereo out of a vintage 1940's radio

Just over 2 months ago, slightly on a whim, I bought a 1940's transistor radio from Brighton flea market with the idea of restoring it and incorporating new tech to bring it into the 21st century.

I’m very pleased to say that I have completed the project and I am very proud of what I’ve managed to create. I’ve learnt a lot along the way, and had a lot of help from friends but the end result is fantastic.

It’s got Spotify built in, Internet radio, Bluetooth, AirPlay, 2.1 amp and speakers and it still looks like it’s from the 1940's. Hope you enjoy the journey as much as I have!

Here is the finished project. Its blue LED is the only hint of what lies within…

How it started…

I had been playing around with a Raspberry Pi computer for a while and stumbled across a software setup call Volumio that allow you to create a great little audio player from your Pi. After playing around for a while I realised that the audio out on the Pi was pretty rubbish so I purchased a HifiBerry Dac+ which allows for great audio straight from the Pi. It’s easy to fit and in no time I was listening to Spotify or using Airplay to listen to music on my amp.

This was great and once I knew it was working well I decided it was time to find a use for it around my home. My bedroom has been lacking music for a long time so I decided I would try and build a stereo for the room. It needed to be small (ish) and I wanted it to look nice.

The flea market in Brighton is great for a stroll on a Saturday and it was there that I saw the radio and without really contemplating the amount of work it would involve I purchased it or £15 and excitedly headed home.

Planning

I spent a considerable amount of time googling to decide on the best approach for the project and came to the conclusion that purpose built PC speakers would be the easiest and best solution. I also wrote a list of stuff I would need and worked out a rough budget:

  • Raspberry Pi model B+ £30 (now much cheaper since the new Pi has come out!)
  • 8gb micro SD card £5
  • Micro USB power supply for Pi £12
  • Wifi dongle £4
  • Case for Pi £4
  • Hifi berry Dac+ £30
  • Creative PC speakers £25
  • The old radio £15
  • 4mm MDF board £6
  • Pine batton £4
  • Varnish £6
  • Glue and fixings £8
  • Laser cutting and acrylic £5
  • Wires and connectors £4
  • Brown fabric £5

Total cost — £163

I probably spent quite a bit more on this project due to trial and error but the above costs are an accurate estimate of what it should have cost!


Getting started

The radio was in pretty bad shape before I started. It looked like Rats had been at it and was quite water damaged.

The first job was to remove the old inards from the box, it was just a couple of bolts and out it came

Here’s the box. You can see the 3 holes in the front where the original knobs were. Early on in the project I decided it was important that the finished stereo still made use of the knobs in some way but at this stage I hadn’t quite worked out how

Once It was apart I soon realised that the box was in worse condition than I originally thought so I glued and clamped it to repair

Whilst the box was glueing I washed the Bakelite front panel and polished it using Brasso.

I also cleaned the glass panel and hot glued it back in place to avoid any rattles or vibrations.

The box was then sanded down and given a couple of coats of varnish which I carefully colour matched to the original colour before resembling the front


Here is the finished enclosure, all ready for some new tech!


Here are the speakers I bought

I smashed the speakers up and removed all the bits I needed and was then able to think about the wiring…

Although the Raspberry Pi would be the primary source I wanted to ensure the stereo could still be used without Internet so I decided to add a switch and a jack input to allow for any audio source to be plugged in and played. This also provided a use for the knobs, they would function as:

  • Audio source selector switch
  • Power and volume control switch
  • Jack input (with a fake knob to conceal it when not in use)

The tweeters were mounted in MDF using bolts and the pots were hot glued on to improve the sound quality.

I cut a rather messy hole in the side of the box and mounted the speakers in it using wood glue and screws. Luckily the side will be covered so I will never have to be reminded of the poor job i did of the hole!

I visted a local community workshop called Build Brighton with a friend who is a member (Mike Street) and used their laser cutter to make an acrylic speaker grill. Once wrapped with brown fabric it was hot glued over the messy hole.


I was now able to size up the sub box and work out how the rest of my electronics would fit in the box.


Next up, it was time to think about the switch. I was able to use a switch from the riginal radio as the input selector so I removed it and cleaned it up

I then made an aluminium bracket to mount it on and fixed it into the box

The volume and power switch from the creative speakers fitted really nicely into the middle hole of the facia so I fixed this in at the same time and also fixed in the jack input.

I made an ‘L’ shaped MDF “shelf” for all of the circuitry and after some serious head scratching decided that it would work best for the circuitry to be mounted on the back of the box so it could be easily accessed in the future.

here you can see the Pi and the 2 power supplies wired together and the amp.

Change of plan!

As I had already wired up a power supply for the Pi which had a spare usb socket and the audio source selector was a 3 way switch it seems far to easy at this point to incorporate a small bluetooth receiver. You can see it here fixed in place with its sync button pushable through the back of the enclosure. Brilliant!


I tried to keep all the wires as tidy as possible (cable ties are my best friend here!) and cut a hole in the back of the case for access to the usb and ethernet sockets of the Pi

It was never my intention for the stereo to have lights but when putting the box together I realised that many of the components had LED’s on and once assembled these were visible through the glass panel. They didn’t really look very good so I applies some greaseproof paper to the glass which helped to diffuse the light a bit. There are blue, green and red LED’s and the end result is rather psychedelic! All that was left to do was screw the back on and fire her up!

The finished stereo

nice!
I’m really pleased with how this feature turned out
Raspberry Pi and bluetooth from the back. 3 settings on the selector switch: Jack input, Raspberry Pi & bluetooth
The stereo still has its original Harrods badge. I also re-felted the feet in red (the original box had the remains of red felt feet so it seemed only right

I really enjoyed this project and the end result is better than I ever could have imagined. I’d love to hear what you think of it.

If you are thinking of trying a project like this then go for it! I’d love to hear how you get on

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