Introduction: Old Radio Transformation

Picture of Old Radio Transformation

I've been reading about Bluetooth radio's for a while, and decided to build something big. My girlfriend wanted a nice radio for her room. I ended up buying an old radio from a thrift shop, a Fridor 521. The radio had a few defects (volume stuck at 80% and bad signal). Since I wanted to buid in a new amplifier from a computer 5.1 speakerset, I did not need the inside electronics. I tried my best to keep as much of the old elements in tact. This Instructable is not a simple "get it out and throw new stuff in" tutorial. I hope you enjoy reading this article.

Check the pictures for notes, some have them. They help making things more clear

Step 1: What Are We Dealing With?

Picture of What Are We Dealing With?

Since I never worked on a old radio, and had not decided what to use and not use, I first took a look at the inside. As I wanted to use as much parts as possible, I considered my possibilities.

- Reuse of the buttons

- Redo paint/wood

- Use same speaker, with new amplifier

- Stream music over Bluetooth

Step 2: Cleaning the Easy Parts

Picture of Cleaning the Easy Parts

I stripped down the radio until I separated all the components from it's wooden housing. I ended up with the electronics, front cover + glass, a decorative plate and the knobs.

All the electronics are stored in a metal compartment as you can find in the pictures above. In this step I didn't do anything with it, I will get into that in a later chapter.

Front cover and glass
I was surprised about the state of the glass and fabric. It was a bit dusty, but no big scratches or other kind of damage. I used water and soap to get it clean and store it for later assembly.

Decorative plate
As you can see in the pictures the color of the metal was not how it supposed to be. I cleaned it using scouring cream. After a while it came out pretty good so i did a last clean with soap and dried it.

I noticed that 2 of the knobs miss their "gold" cover, but since the knobs are divided 2 by 2 on each side, I was ok with that. If you take a good look at the first picture showing the knob, you can see a lot of dirt on it.

I used my ultrasonic cleaner with a simple solution of water, vinegar and dish soap. A first run did clean a lot (compare picture), but I decided to put them in 2x 10min. The plastic residue on the last picture was removed later.

Step 3: Make Room for New Electronics

Picture of Make Room for New Electronics

As I said before, before people argue about the fact I "destroy" the inner working, there were too much defectives for me to take care of i decided to put a new amplifier in. This is the reason i didn't buy a full optional tube radio.

One of the potentiometers was broken, so I had a good chance of taking a look inside. The first problem I encountered was the difference between mono and stereo potentiometers. The old radio only used a 3 wire potentiometer, but I wanted to use the 6 wire potentiometers from my old amplifier.

I came up with the idea I might be able to use the broken potentiometer as a housing for my 6 pin potentiometer. The picture shows lockbond at the tip of my potentiometer, but I ended up using hot glue instead.

Frequency chooser
One of the old buttons was used for selecting the radio frequency. This came out to be a great solution for an on/off switch. The picture shows the 2 dials used in this radio. The one in the left is still as is. On the right one I took out all pins, except three of them (I needed 2 for my buttons, but without the 3th one, the middle ring fell out his housing). I think we don't see electronic solutions like that any more, so more reason to keep it like this!

I've added a breadboard to so I was able to connect all the wires (3x6 for potentiometers and 2 for the power switch) to their individual terminal block. Doing it like this I am more flexible placing the amplifier PCB later on.

Step 4: Adding the Buttons

Picture of Adding the Buttons

Remember those potentiometers from the previous step? After i finished them like that, I found out I was not able to place them back just like that because they would turn around freely. I needed to mount the potentiometers stuck in place. I went to the hardware store and got myself some threaded wire (M3). And carved a wooden body using my dremel. Wearing protective gloves could prevent you from cutting yourself, like I did...

Custom potentiometer
After I did all my preparations on the first potentiometers it was time for a new challenge. The old radio only used 2 potentiometers, so I had to find a new solution for my last potentiometer (I need one for volume, bass and treble).

The axis previous function was to change the frequency for choosing channels. I used a table grinder to get a nice V-shape to fit my potentiometers notch.

On/Off Switch
As described in the previous step I wanted to use this one as it is. After putting it back I had plenty of place to solder the wires in place. I used my multi meter to check for resistance to make sure the 2 wires make contact in "on" position.

Step 5: Wires, Wires an More Wires

Picture of Wires, Wires an More Wires

Pretty straight forward step. The only thing important is to get the order of the wires correct, thats why I marked my breadboard with a 1 and a 6.

Step 6: Preparing the Amplifier and Hook It Up

Picture of Preparing the Amplifier and Hook It Up

Desoldering components
The potentiometers in the previous steps are the original potentiometers from the amplfier I am using. I desoldered them using my soldering iron and desolder pump. To clean the connections I used a desolder wire to make sure all tin residue is gone.

I did the same thing for the on/off button, line-in socket and power socket (will use that for a small portable bluetooth speaker I will build after this project).

Power supply
In the next picture you find the power supply for the amplifier. I placed the parts on the old electronic body. I needed to drill a few extra holes.

Soldering wires again
All the places that contained a component, now contains a few wires. I had to make sure the order of the potentiometers was correct. The rest was not that hard. I now ended up with a working amplifier with "new old knobs"!

Step 7: Adding Bluetooth Functionality

Picture of Adding Bluetooth Functionality

Before i get into this i want to thank user Barry_L for his help, explanation and advice regarding Bluetooth chips and how to use them. Check his Instructables if you are looking for places to buy a KRC-96B for example.

For this project I used a KRC-86B. This module operates between 3V and 5V, only problem that my power supply provided 14V. I used a simple USB cigarette lighter as a step down converter to bring the 14V back to 5V. The picture of the cigarette lighter is an indication of the part needed, it is not the actual part I used.

Hook it up
Since it was a bit of a struggle for me to find good examples of how to hook this module up, I drew a schematic to make it more clear.

You can also add some buttons if you want (for next/prev song etc.) check the KRC-96B datasheet for more information. Wires I used are VCC, GND, AGND, OUTL and OUTR, so you need to solder 5 cables.

I found out I had to put a jack plug in the aux out to make it work. I used a cut plug from some old headphones, maybe this note helps some people in trouble.

Step 8: Fixing the Wood and Painting It

Picture of Fixing the Wood and Painting It

My plan was to sand the whole body and oil it. Unfortunately it had some nasty damage on it's upper left corner and had to glue one joint again.

Sanding and filling
In the process of sanding some of the veneer came loose or was so thin at some places, so we decided to give it a paint job. We still wanted to retain it's old look, but some reparations had to be done. I used some filling primer to reconstruct the wood.

My girlfriend wanted to apply the first layer of paint. After that we went into a process of adding paint, sand it lightly, clean it, paint it again. After continuing this process 3 times we are done painting, finally! Curious about the result?

Step 9: Puting It Back Together

Picture of Puting It Back Together

While I was enjoying the last steps in the process I totally forgot about documentary. At the end of it all, this one picture tells enough of the process right? I also added 2 tweeters for high tones. For now they are not mounted next to the big woofer, because I don't have the right drill.

Step 10: Final Result!

Picture of Final Result!

I am pretty proud on making this project. I ended up with a fully functional Bluetooth radio for my girlfriend. I want one too!

Any feedback, questions or other remarks? Feel free to drop them in the comments!


TomEdmondson (author)2017-10-27

FINALLLLLLLLY - Someone that gives the (very detailed) step-by-step process of doing this AND 'exactly as I needed' for my radioReSOUNDing project. Thanks

EmillyBint (author)2015-08-28

Wow, this has vintage written all over it. Amazing idea! My mother has an old soviet tv somewhere in the garage. Maybe I'll manage to make something out of it?

lgotje (author)EmillyBint2015-09-07

Good luck! Would love to see it

FlorinJ (author)2015-08-24

Did I correctly recognize a tube-based amplifier in there? If yes, you should have kept the original amplifier. I have an old radio myself (, wouldn't change its amplifier for anything in the world.

SQ2KTN (author)FlorinJ2015-08-27

I also thought this - could you reuse the tube amplifier?

lgotje (author)FlorinJ2015-08-25

I will surely buy a new tube radio and just add Bluetooth to it. Probably make an instructable of it.

spark master (author)2015-08-25

Honestly, it is hard to fix an old tube set. I learned to limpingly do it back in 1974. Fixing it was how to pass the final exam.....if you cheated by doing some reversible sabotage, hmmm. You had to hand in the dead radio 2 weeks b4 the final. Bro Peter would fix that for you, and say nothing..... chuckle...

A long Time friend of mine bought a reproduction of a "cathedral" radio. You just add your electronics, new or old.

juicer62 (author)2015-08-25

That chassis is in GREAT shape from the pictures. The better art would have been to save and use the tube chassis, and incorporate modern use of it. I have 14 antique radios, from the 1920's to WWII. They lose nearly all value when you gut them just for the cabinet.

spark master (author)juicer622015-08-25

99 % of the value

lgotje (author)juicer622015-08-25

I bought it for less then €20, so it had "no value" before the beginning of the project :)

MariL1 (author)2015-08-25

so, anyone try to run such a beaut on a solar collector? Would I need the collector panel wired to a "converter" or inverter? I forget which, and what is the difference between them? Why don't we have solar and converters in every room of every house and office? Would you be able to convert//subvert any such old parts to make a micro-hydrogenerator? I believe every moving body of water should be put to work passively turning crank-style generators, like bicycle wheels or barn-size fans to generate electricity, wired into battery arrays and direct-feed outlets to nearest electric usage in neighborhoods, malls, shops, schools. We have all these streams, creeks, rivers, shorelines all over and around us being polluted for the last 100 years while we create electricity with foul coal, dangerous nuclearadiation, or wood-fired steam of old days....why not go directly to the water's dance and be fed cleanly, naturally, and cut the cords that bankrupt every household and business every month....think of it... $75 - 2500 a month winter and summer, urban or rural, every house, apartment and business paying for electricity that should hav been free (mor or less) for the price of a community project for a few years, plus plenty of jobs and money for the gathering of resources to construct and wire with....what's wrong with us? When someone drooled over money to be made off the public, they mobilized every city and town and wired us up for electricity in a few decades...why can't we do the same to cut us free of Waged Slavery to the utilities and corporations needless, polluted electricity technology and institute free electric- community management & development for jobs?

life hack_ DIY (author)2015-08-25

It made a lot of work. But the result is not very definite. You should not have to spoil the old electronics. It is so beautiful and the old! Thank you for the golden hands, but I like the vintage original !!

Pa1963 (author)2015-08-24

Another option would have been to get a sheet of wood veneer and lay it over the old wood.

gargrag1 (author)2015-08-24

Hi, Good project!

Which amplifier did you used?

lgotje (author)gargrag12015-08-24

It was an old I got from a few years ago

IDMASON60 (author)2015-08-24

I first kind of grumbled,however the end product was a great surprise.You used enough of the old components to allow you to make the cabinet more functionally in a modern way.

Great job..

kschmidt2 (author)2015-08-24

So this'll sound like an odd request, but any chance, if you still have the old internals, you could sell them to me? I'll pay shipping if the prices all come out right.

Nice build by the way, but you could've added an input to the original radio.

lgotje (author)kschmidt22015-08-24

The tubes I salvaged will be used in an other build when i find myself some other old tube radio. Sorry

kschmidt2 (author)lgotje2015-08-24

all good man, I was hoping you wouldn't scrap them. I love the old tech and I would've been heart broken if you were going to chuck them, but, they're being used so I'm happy.

Donc2 (author)2015-08-24

I'm just flat out impressed....& maybe a little envious...I wish I had the know how..

jeanniel1 (author)2015-08-23

Really good job converting the insides, updating them. I have a full size cabinet / record player / radio I'd love to convert. Just that the transistor tubes still fascinate me. Maybe I'll put a glass panel on the front and show them off, and hide the modern stuff in back of another panel. Your 'ible gives me some ideas!

mv2rn (author)2015-08-23

What a great idea! I have my mother's old radio, and I would love to keep it as intact as possible. Sadly, I haven't the first clue about the 'internal organs' and I'm afraid to turn it over to a stranger that claims to know what they are doing.

lgotje (author)mv2rn 2015-08-23

From what I have seen, there are a lot of old radio lovers who like to keep the internals intact. Maybe they can show you any examples, before they start off.

Phil_S (author)2015-08-23


Can't help a little nostalgia for the old radios. The warm smell of valves heating up, the Home Service, the Light Programme etc. The radios were furniture rather than electrical goods. The telling thing is just how many DAB manufacturers resort to wood/vinyl finishes to make their goods more attractive. Unfortunately, the reality of valve radios also meant Sunday night washes in the tin bath. DAB is fine, but too clinical - nothing to beat fine tuning the wavelength knob to get Radio Luxembourg, a good earth rod and 200-feet of aerial.

What actually caught my eye was the fine display of Rudbeckia flowers (Black-eyed Susan etc.). You can see the sunflower/Jerusalem archichoke origins in the leaves.

humphrey.lees (author)2015-08-23

I restore the original to working and use the gram input for Bluetooth whatever for input. I usually have BBC radio 3 running. As an amplifier would be needed anyway, I think this works beautifully. I can also play my cd's on the computer and listen to the 1940's radio.

Something else I tried was a little transmitter that was picked up by the old radio from the computer


SoakedinVancouver (author)2015-08-23

Good re-use of a nice case and speaker! Did you give away the leftover old parts of the radio to a local "tubehead"? :)
get a bit of the old tube radio sound, an old trick was to simply put a wirewound, 1
ohm/20Watts power resistor in series with each output wire of your
modern amplifier. That is a total of 4 resistors, one in line with each
"+", and one each with each "-". this trick does work pretty good with
conventional transistor amplifier, A, and B type. I do not know how
well it works with type D, and its variation. Cheap to try!

watahyahknow (author)2015-08-23

wat you can do to make a somewat flexible connection between the shaft of the old potmeters and the newer potmers is slide a small piece of rubber fuelhose over the two , its about the right size for that stuff

you can clean up the wiring by twisting it intoo two stings , prolly will help with some of the interference too

if you can find some older style external speakers like for a jukebox or a PA system you could add a 2 channel amp in there with a filter and use the mainspeaker for the low tones and send everything else to the outside speakers

might even use the inner gubbins of a computer set for that

lgotje (author)watahyahknow2015-08-23

thanks for your advice. I will surely check that. I already included a amp with 3 channels. One for left and right and one for low tones (subwoofer).

bobby.dunn.92102 (author)2015-08-23

You Did great. Though I do hate to see these wonderful old sets get destroyed. I repair and restore radios here in the States. Again you did a great job of modding an old set. You can also build or buy an AM /FM transmitter and get the warm sound from a tube set. Thank you for sharing your project.

lgotje (author)bobby.dunn.921022015-08-23

next time I will buy one,I will try to restore it and add bluetooth to it.. Thanks for your reply!

robinbrichardson (author)2015-08-23

Well done!


GennadiyG made it! (author)2015-08-23

I've made kind of the same from Russian old radio.

Without much wiring, but quite the same. Good job!

arex (author)2015-08-23

Nice job.

heibert (author)2015-08-22

Good job, but... actually you got multimedia active speaker instead of warm tube sound antique thing. May be you have some chance to recover original amplifier? It could sounds more consistent to exterior. Sorry, i'm crazy soundman ;-)

smandal13 (author)2015-08-21

great job

kailash.mehendale.7 (author)2015-08-21

Great job man! Quite inspiring, Best wishes.

Good to hear I achieved my goal :)

Barry_L (author)2015-08-21

Cool tutorial Leon, great to see it written up! Sounds pretty good too. Also, did you do the drawings in step 7 yourself? They're very good!

lgotje (author)Barry_L2015-08-21

Thanks Barry! I did the drawings myself. Hope I made it more clear like that :)

DIY Hacks and How Tos (author)2015-08-21

Very cool.


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