Bluetooth Boombox: Retrofitting an old radio

If you fancy making one yourself, there are a couple of links to the important parts below:
Bluetooth receiver - ebay.us/RI0o06
Pam8403 - ebay.us/TaUzg2
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[@tectalabyss]

I am happy you didn't destroy the vintage part's of the set. Great job on the mod. All the best. Bobby

[@ahah1785]

Im listening to this on a retrofitted 1956 radio with Bt

[@ruantengyi]

Wow! Nice job! It really proves that something vintage can get a second life!

[@Moonwalker917]

I love the fact that you didn't destroy the radio circuitry unlike some people. You rock!

[@MkmeOrg]

Great job David! Love seeing old tech reborn. Cool project. Cheers

[@stephenjeffreys4219]

Great video thanks - gives me the insights to convert my old radio without trashing the internals.

[@Geeksmithing]

Very cool video David. Thanks!

[@LeeBinder]

Great Piece. I have been thinking about the same kind of project so your discussion was helpfull

[@BanazirGalpsi1968]

assuming yo also incorperate the old valves in the new works it will really rock. cause valve/tubes sound awsome.

[@ohioman3704]

I did that same exact thing except the radios tube amplifier circuit was still functional but the radio circuit was completely not worth fixing so installed a stereo input jack and some resistors pretty much like if you were installing a switch and jack in back of any other tube radio minus the radio to mp3 switch since the radio would never play radio again.. works really well with bluetooth connected.

[@iandavidharwin]

Anyway to better explain how you wired everything? Where does the 3.5 wire go after you plug into the Bluetooth?

[@magidfathalla1717]

amazing work thank you

[@TheSpotify95]

Nice modification - but you need a ground isolator because there is noise on the output (common with those Bluetooth chips) a 5V DC-DC converter will do it.

[@Cobwobbler]

Could you use a similar set up in an old car radio? Can you get more powerful amp kits and from where? Cheers for the Video David, good work.

[@practicalguy973]

That's a really cool use of an old radio. I hear some ground loop noise over your talking when the Bluetooth is connecting and when your pausing the music, you know that phone signal/old school modem signal sound. In a quiet room that would be really bad but its easy to solve. You can get a different Bluetooth receiver that has a built in battery or you can invest in a ground loop isolator. What it comes down to is that the amplifier can not be on the same power supply as the bluetooth module. One with a battery/charging system is automatically isolated and many can be found with batteries built in. If you make that change it will be silent! The ground loop isolator will degrade the sound a little. I suppose another option is you could get another 4 AA batteries in a separate battery holder and power the BT module on its own 4 AA batteries.

[@DavidWatts]

Thanks dude, I tried a ground loop isolator but it didn't really help too much. The power supply route works the best in my experience. Thanks for the comment, I am sure people will find it really useful. My ears might not be good enough to hear all the issues to be honest.

[@practicalguy973]

The ground loop isolator works in most cases but not perfectly in my experience either. I tried some on a BT speaker that I was having loud ground loop distortion and it fixed the issue but the sound quality was strange. I read that the ground loop isolator boosts the signal and can cause input distortion of its own depending on the tolerances of the devices you are using them with. I then invested in a USB power-bank to power the BT module and that fixed everything. Now I know better when I'm designing my next DIY BT speakers! Cheers and good luck with your future projects.

[@papobado9793]

@@practicalguy973 Could you tell me how you connected the USB Powerbank with the BT module? How do you charge the Speakers then? I'm new to this sorry.

[@practicalguy973]

@@papobado9793 There are a couple of different setups I've done. 1 all USB powered using a USB power bank, a USB amplifier and USB BT module. I use the ADUM4160 USB Isolator between the USB power bank and the USB BT module. That isolator breaks the ground loop at the power input of the BT module. That is the best way to not have ground loop noise. The other way is an audio ground loop isolator and that reduces the issue but does not solve it entirely in some cases, audio ground isolators plug into the audio signal usually through 3.5mm stereo or RCA audio jacks. All you do is plug the USB amplifier into the other USB port of the power bank and its done power wise! USB amplifiers are very low power so this is only good for a small speaker. Look for something that has connectors for power, audio and a volume and then its just plug and play. Something like this www.ebay.com/itm/Mini-Audio-Power-Amplifier-Board-5W-Dual-Channel-DC-3V-6V-5V-USB-Adjustable-Knob/192279855021?hash=item2cc4c5bfad:g:Mx8AAOSwighZlAUG

[@practicalguy973]

@@papobado9793 If you intend to make something large then you need to go higher in power. 12v amplifiers and 12v batteries can get you hundreds of watts. I made a bigger speaker with 12v setup with a AGM battery and a car amplifier and I retro fit a couple 12v accessory sockets and 1 of them i put a 12v USB car charger. I put the ADUM4160 USB Isolator between the USB car charger and the USB BT module and that breaks the ground loop in that system. The hole thing with ground loop is you can not have power of the amplifier and BT module on the same wire. Break that and clean sound! ADUM4160 USB Isolator is worth it but remember this, it is very low power. You only use it on low power BT modules. If you try to put too much other power hungry devices on it it will burn it out.

[@MrHbpatel]

Good for retrofit solution.

[@evanmcswegan4889]

You look like respectable Colin furze, I'm really confused. Great video dude.

[@ernstgrunbauer7724]

Hi, great job ! Do you know how to change the Name from your Bluetooth Modul into some Name of your own ?

[@Educ8s]

This is great. Well done! I have similar plans for my old radio as well. I plan to to use it as a standalone mp3 player. I love old stuff. I think you do too, no?

[@DavidWatts]

+Educ8s.com I do indeed, it would have been nice to have as a radio and bluetooth boombox but alas it may be too late for the poor thing.

[@JS7457]

+David Watts You can buy a cheap radio on ebay and make a hole for the pot and the antenna. It will be great ! Some old knob will be good.

[@MrHbpatel]

can you include add small sbc may be orange pi pc15$. and create multiroom audio streaming system. eager to see future episode base on this. !

[@returnofthemac100]

hi, this is great. I'm about to do the same to an old Roberts radio. Please can you tell me how long the batteries last? I'm wondering if I should put in a power adapter as an optional extra. any advice will be gratefully received.

[@JethroBoDean]

Yes if you are going to leave it on a shelf or desk etc.. I think he used the battery to make it portable but if your not going to mobe it around then the DC converter plug would,be a better option

[@papobado9793]

Did you do any soldering?

[@RealationGames]

Would've been neat to add Little Bear P5 or similiar cheapish tube amplifier to achieve that vintage sound.

[@GoldTopSlinger]

I didn't know that existed! Thanks for mentioning it. I'm going to do this same project with a 1941 Zenith, streaming my OTR (Old Time Radio) music, newscasts, sportscasts, etc, and it had crossed my mind that it wouldn't sound as warm as it did back in the day because there'd be no tubes involved. Saw your message and picked up a Little Bear P5 from Amazon for $49. Well worth it.

[@dvideos1849]

there is a ground loop !

[@nor4277]

Thats the kind of radio a lot of us try to save,maybe you can do both ,save a nice tube radio and add your blue tooth .it value would go jp as a blue tooth only I wouldnt buy it but as booth,I tbink its more sellable,maybe someday you want to get rid of it,you would have more choices,doesnt look like it would take much to do both ,but its your project.have fun

[@JethroBoDean]

A lot of those radios have field,wound speakers in them not the same,as that aa battery would not be able to push it

[@jonl9801]

I’m building a similar project out of a 1948 Philco. Mine’s gutted and going to be a complete rebuild with updated parts.

[@neptuneflare4994]

Nice One...

[@keithd3964]

Hey, great video. I have a retro all in one wooden music box. It has all types of music modes vinyl cd tape radio, I want to add an aux or Bluetooth. Could I use the wires from the tapedeck to hook up ither Bluetooth or aux? I don't know how to soulder or am I electric savy. But I'm sure it would cost a bomb to get someone to do. So I'd like to do it myself. Any help much appreciated.

[@DavidWatts]

If you don't fancy soldering then I would pick up a car cassette MP3 adapter.

[@DavidWatts]

+Sas Quatch Sorry mate, I too would have loved to repair it. I did a fair bit of research but with two Valves missing (unknown part numbers and no schemtaic) and a crusty old transformer I didn't feel it would be worth the time or actually all that safe to try. I chose not to damage the internals in the hope that one day I will see a similar radio and figure out what parts are required. That said, had I been able to fix it, I would still have modded it to take another input as well as it usual radio frequencies.

[@evelinedeun7240]

+David Watts hey, man! i have been looking for a tutorial for a long time and yours is the best i found so far. I got a Tesla radio from the late 40's a year ago and the only thing it does when i turn it on (by just plugging it) it is a deep buzz so i don't think it is possible to fix it and if it is, it is gonna cost me a lot, so i would like to follow your steps. My idea is to empty most of it and only leave the speakers, wich i hope still work. Do i only need the components that you describe on your video? I hope you can help me out, i have no idea at all. thank you.

[@DavidWatts]

+eveline deun Hi, thanks for the comment. You only need the components I mentioned, essentially I just used the radio as a speaker cabinet. If the insides look cool though, especially with valves, I would leave them.

[@evelinedeun7240]

+David Watts i don't think i can build up that circuit myself to be honest. i don't even know the name of all those components. my question is, how do you turn it off? with the battery case swith? because that would be inside of the radio. Unless you leave the back side always open. Sorry for the questions but it is almost chinese to me.

[@evelinedeun7240]

+David Watts i also forgot to mention this old radio has 4 speakers.

[@DavidWatts]

eveline deun The radio already had an on/off switch built it. Mine was the volume control so I tested it with a multimeter. I talked about the switch here - kzbin.info/www/bejne/i3XOo3hqqNx9nsUm12s You can only connect 2 speakers to the PAM8403 amp but you coud add another amplifier if you wanted to use all of the speakers.

[@spaceadventurer100b8]

Thanks for another good video. Could you help me please. Firstly, how would I connect the dial to be able to choose different mp3 tunes on a usb stick as you would use the dial to choose a different radio station? Secondly, how would I be able to connect to a KZbin video? Many thanks in advance

[@Nebby_99]

For this I think you would need a Raspberry Pi or similar, and some custom code.

[@francescamoore1607]

How do I find out what wattage my speakers are?

[@arthurdanielles4784]

Valve radios had a 3 OHM or 15 OHM speaker. The mods that I have done to convert for bluetooth USB to amp to speaker 🔊 I've swapped the loudspeaker for an 8 ohm mid range. You can sometimes use a car speaker 4 ohm which delivers reasonable sound but it is wise to check outputs re rating for the speaker from the amp.. Using a 3 ohm on a 4 ohm out won't cause too many issues but if it were an 8 ohm output into a 3 ohm speaker NOT advisable. Also the radio you have there has a LIVE chassis re the original radio and thankfully you are NOT continuing with restoring that. For those not understanding what a LIVE chassis is, it means the mains power YES all 240volts of it go through the metal and if you were to put your fingers on it when power is connected it would certainly come a SHOCK to the senses. I've used the volume control / power switch no probs to switch my units on / off and adjust the volume.👍

[@casposa]

Hey, in your breadboard I see a capacitor. What is it there for and what is it connected to? I am trying to repurpose an old radio myself :)

[@DavidWatts]

Just a 10uf decoupling capacitor.

[@casposa]

got it, thanks! 8)

[@supercheekykiwi]

would have loved it if the other knob could have been working as a volume.

[@dozza202]

You should of made the other knob the volume if you could

[@prufrok]

I do a lot of these and have zero interest in restoring the old electronics. I keep the chassis and tubes for looks and use the switches when i can but the number of people wanting to pay hundreds of dollars for AM and even FM radio is near zero. The only people who complain about this are the cranky old nostalgics with one foot in the grave. When buyers have to try to get therm fixed when tubes, caps eventually go, its much less romantic

[@JS7457]

I already tried this with a similar bluetooth receiver key but if i power it with the same power supply of the pam8403 it make sound distorsion and don't work. I use a 18650 with a 5v step up converter. GreatScott! have thid problem too : Make your own Low Budget Bluetooth Music System And i saw that you pay too much for the items you buy, if you want better price how can i contact you ?

[@DavidWatts]

+JS7457 Thanks for the comment. I assume there wasn't enough decoupling on the power supply especially if it was an already noisy switching supply. I didn't hear anything using battery supplied DC. Do I pay too much, I thought they were pretty cheap especially delivered in the UK. You can find my email address on the about section of my KZbin channel page.

[@JS7457]

+David Watts Thanks, maybe it's a receiver problem. If is delivred the UK it will be more expensive than if you buy in china. I pay the receiver for $2.89 (1.88£) on aliexpress. On french ebay they are at 12€(9£) send from france. But what i don't like is to wait to receive it from china.

[@practicalguy973]

+JS7457 Some BT receivers/amp combinations can be worse than others but this is a ground loop feedback issue. You need to use a ground loop isolator on the signal path or use a Bluetooth receiver with a built in battery. You cant have an amplifier and a Bluetooth receiver on the same power supply or feedback will happen.

[@JS7457]

True, then how an ordinary bluetooth speaker doesn't need a gound loop isolator ?

[@practicalguy973]

You can also simply use a second power supply and that will eliminate the ground loop completely. For example have one set of batteries to run the audio amp and another set to run the BT module. In my case I used a small USB power-bank to power the 5v BT module. This is cool because it can act as a phone charger also!

[@rogertyler3237]

You dont need anything in there except the switch & the speaker. But install A good sounding speaker

[@AReitmeyer25]

would it be possible for you to send me a list of parts via e-mail, Along with just slightly clearer connectivity instructions?

[@judekershaw6143]

Could you please do an even older radio? Say 1930s?

[@DavidWatts]

You know if I could afford a nice looking but broken art deco number I would.

[@rogertyler3237]

I'd just use an all in one 50 watt per channel Bluetooth amplifire

[@EngineeringNS]

You should get into lithium (18650 cells or lithium polymer from old phones and tablets). they have good capacities and are pretty simple once you learn how to use them. It pains me when I see you using AA batteries in your projects.

[@DavidWatts]

+Kris S Hi Kris, I use LiPo batteries all the time but for this project AA batteries are simply the easiest solution. In this scenario the amp will stop working before the batteries are discharged to a dangerous level but if I were to use a LiPo and a boost chip (L6920db or MAX1797) I would also have to create some circuitry to prevent them from over discharge (A TC54 perhaps). I am making a couple of portable projects at the moment with LiPo batteries so hooefully the next couple of videos will ease the pain :-)

[@JS7457]

+David Watts You could use a tp4056 to charge the lithium battery

[@DavidWatts]

JS7457 I tend to use the MAX1811 or the MCP73831T when charging LiPos, I guess I am just used to them.

[@EngineeringNS]

+David Watts awesome! I look forward to it.

[@JS7457]

David Watts You can too but with tp4056 modules you can charge at 1A, you can find tp4056 modules with circuit protection include too.

[@jeffpolaras9273]

Valves? You must mean Tubes?

[@onioncasserole9498]

links are no good anymore

[@DavidWatts]

Thanks, fixed it.