Hey, Terry from D-lab. I recently finished my first Radio. A 1941 Silvertone 7037. In the process I met Mark from Antique audio who lives right down the street from me in Plymouth, MI. He spoke of you, and I will hopefully be seeing and meeting more of you guys. I am interested in adding a jack to my Radio. So, here I go!
I just did this to a fully restored 1937 Westinghouse 12 tube console radio. It works GREAT!! I plugged a USB rechargeable bluetooth receiver to the jack and now have both options. Brought new life back to this radio! Thank you D-Lab Electronics!
Thanks so much for posting! This is perfect for listening to my Old Time Radio shows (on an old-time radio, of course). As I type, Fibber McGee & Molly are visiting.
Thank you Terry at D-LAB! I just did this MOD on my 1939 WARDS Airline and now I'm listening to "40s Junction" on Sirius XM Radio streamed from my phone. Sounds amazing. Your videos have truly changed my life with my guitar amp & radio hobbies. I've built many guitar amps now and restored amps+radios thanks to your helpful videos. I'm enjoying this so much. Thank you again!
That is a beautiful radio... My family had one very much like. The main difference I see was that our radio had the old FM broadcast band which was 42 to 50 MHz. We spent many an hour listening to favorite shows on AM until television came on strong in the mid 1950's. Wish I still had that old trooper! 😊
Terry, I greatly enjoy your videos. Very few channels that I watch on youtube or that are worth watching. Yours is certainly one worth watching. Hopefully will be able to someday do this with a few radio's that I haven't gotten yet but plan to and give as gifts to my kids. They enjoy classic older radio's like I do. Guess they got that from their dad. Keep up the good work. Brian
Now that was a nice simple conversion to get your old tube radio to play MP3's Might try this on some old tube radios I am restoring thanks for the information.
I have a 1937 Stewart-Warner console that I inherited from a great-aunt who bought it new. The thing is branded "True Value Hardware," but made by Stewart-Warner!
Awesome mod, but yet keeping it orignal. One tip too is you can buy bluetooth to aux adapters that are basically plug n play. Can add more descretion to the radio than having a aux cord hanging from it. Will be trying this, thanks for the awesome video.
Cool, I have a Motorola 10T28B tube radio AM-FM with a phono input. I use an adapter that has two RCA jacks for MP3, CD, Bluetooth receiver or a turntable. I had to have it serviced a few years ago, but it is good to go and sounds even better. I can't wait to get an old RCA Victor 45 record player with a RCA phono output which is what the radio was designed to also play. Nice video!
A friend won a Discman back in the 1990s and I converted her old transistor radio to take a signal from it. The hardest part was getting a jack, the local stores had completely run out of them.
Thanks, Terry. I just repaired and recapped my first tube project. It is a GE 226 AM radio (~1950). The problem is, all the AM stations around here are talk radio! 🤨 I have the parts, so that's not gonna hold up this project.
The extra holes were there because the manufacturer used the same chassis for radio-phono combinations . Zenith radios were often better than RCA but RCA almost always included a switched phono input which would preclude the mods shown here. Experimentation with resistor and capacitor values can improve the sound quality of this arrangement if one has the time. The output of the I-pod is probably around 600 ohms while the audio line in the radio is in the 200-500 k ohm range. But it still works and those radios had a good tone control circuit which should help..
I was suprised that why a capicitor, somthing like 4.7 mfd was not used before 10k resistace to couple mp3 signals so that it may protect mp3 player from any AC current leakage from the radio .? Please comment
Thank you very much for this! I have the exact same radio and have been toying with the idea of adding an aux jack to the back for years. This makes it super easy since you have the exact example that I need to do this! Great video!
Wow, I can imagine playing some of my old time radio theatre of the mind MP3's over a set like that. Sure wish I had the old set we had back on the farm in the early 60's when we first got electricity in the old farm house, man that would be so kool. I will keep an eye out for such a set in the yard sales of the future. Of course not a lot of space for such a unit in our Motor Home, but right now we are stranded in our Sticks and Bricks home because of illness and several recent deaths in the family. Getting old sucks!
Jerry Ericsson That’s what I did with my old 50’s console radio. It’s hard to describe the sound of the old shows on period correct systems. It’s a whole other experience with the flat booming sound yet with tube softness. Worth it.
I have a 1940 Emerson DS-436 I'm in the process of restoring. I never tried this before, but as this radio has a 'push-pull' 20 watt output amp, I thought I'd give it a try. It has a photo plug (not a jack), so easy to connect. I did it exactly the way you showed, but the volume is extremely low, as compared to the radio volume. I'm going to try another cord from my mp3, maybe that's the problem. Just seems like it needs far less resistance from the jack.
Found a couple of your videos really helpful. Thanks for making these. You should probably have a disclaimer on this type, there are line level voltages on some switches, and most don’t know what a hot chassis is.
I noticed your warning at the beginning...The key word is transformer. many don't realize the dangers involved in doing this mod on a series heater string AA5 :) Cool video :)
A hot chassis in the series strung AA5's can have a hot chassis where AC voltage can be present on the chassis. One side of the AC line is connected to the chassis. it can get dangerous and affect the MP3 player...
I have seen this done on an AA5. You just need to add an isolation transformer. Plus, some devices do have isolated power supplies too and these may work fine on an AA5
Isolation transformers will do the trick, however, some radios have limited interior space and there's no room to install one. you would have to have it externally.
Hi, didn't work for me. The radio bled through to both sides of the swutch. When you say to "build up" the high side point, do we add a piece of metal to that point to GET AWAY from the high side solder point to prevent bleed through? I'm confused...
Excuse me guys but I am new to this, after digging around on the interscreen for info on a Zenith X334 and also looking inside the radio I did note that the ac power cord has one side soldered to the chassis, so in my assumption this is a hot chassis radio. Right? So my question is if I install a isolation Transformer can I do this mod to the radio using the same resistors. thanks any help would be appreciated.
This is what people used to do to turn radios into guitar amps back in the day, I reckon. You could also add a Bluetooth device that outputs audio into a stereo jack, connect it in this new input, this way turning your Radio into a Bluetooth speaker!
Hi form cold England I have a old rockola juke box with a stereo valve amp that uses a ceramic cartridge with a high output is it possible to get something that would allow me to play a mp3 player through the ceramic cartridge input plug I have tried it but there is no sound even with the mp3 volume turned right up barry
I have question and correct me if I'm wrong. The volume control (pot) has 3 lugs. The left pot lug is connected to the middle lug of the switch. The top pot lug is connected to the top lug switch.
just wandering if its easy to use an fm/am with bluetooth trasmitter just like the adapter for a car stereo to play mp3 on the radio without modifying the radio or if you just dont have the necesarry tools for the job?
Jack Graham back when I was a kid in the late 1960s -early 1970s I drove a 1962 Dodge that included one of those "hybrid" radios with the " space charge" tubes that only ran 12v plate voltage and a transistor audio power amp. I moded that radio for an FM tuner ( those old FM to BCB RF converters sounded poor) and later for a cassette player. The fun part with the 1948 Olds radio is if it had one of those Delco synchronous vibrators. Those vibrators were problematic and not readily available today. But I hope you can get that set working. Those Olds radios were usually upgraded with push -pull audio output, a tone control that really made a difference and a better speaker. Good luc
Wonderful mod, grateful thanks d-lab for the presentation and schematic too! I did a 1933 Majestic 461 and next will do a '37 Philco 37-630T and a '34 Zenith S-871. Makes these old gals sing beautifully. One question though. The volume is a little weak (I use a small pre-amp to boost the iphone signal to obtain an audible level through the radio). Could I use two .5K ohm resisters on the plug to get better volume?
i have done that on a few old transister receivers and installed Blue tooth devices,one is a crosly I-Juke and my girlfriends Thomas radio and cassette took out the cassette and i can slide the smart phone in it for storage...Its alittle muddy and I see what I did wrong for got the 1 k and the 10 k's ...the jukebox is clear as a bell. .thanks..
@@holmespianotuning I just did a few with an actual line input jack. I ended up using an audio transformer to create the isolation and impedance matching between the radio and the device I would be plugging in, that way there is no connection to the chassis. That is probably the only way I would trust it.
Hello and thaks for your video!! I have a question. You put a mensage on video: "Caution: Do not perform this mod if your radio does not have a power transformer!". Could you please explain why?..is dangerous for the voltage?. And if I have a radio without transformer.How is the rigth way to procede with the aux input? Thanks!!!!
The mod is working on the Zenith 10S669 that i am working on but i need to turn the volume up all the way on the Zenith and quite high on the input source otherwise i hear a lot of static. The radio was gone through by someone else and it looks like all the parts were replaced. Maybe it is normal that it requires a high level input. The radio does not require the volume being up so high.
This is true, the voltage output of many modern devices is really not quite enough to drive the audio amp on old radios like this, at least if you don't turn the source device up all the way. Part of the reason for this is that the radio is a high input impedance device, but the modern source has a low impedance output, which means high current capability but low voltage. Putting a little transformer in between that can step up the voltage can help. A better solution could be to add a little transistor (or tube) gain stage between the audio source and the radio volume control, although this can be beyond the scope of some people who might be doing this mod. One interesting solution (believe it or not), which I have done, is get a nice cheap AC powered phono preamp, and put this in line between the modern signal source and the jack on the radio as described in this video. It will give it a bit of punch with extra bass as well, which may almost be too much, you could probably adjust the tone control on the radio to compensate for this.
Among a hundred comments .. no one has given the specs and circuit to include a capacitor of transformer to protect the MP3 player ? Can someone please do that ?
Early in the video he shows that connection, it's where the radio signal is fed to the pot. You disconnect that wire from the pot, attach it to the new switch, then run the wire connected to the center wire of the switch to where the wire was removed from the pot.
Nice, how about a video on converting the radio to Bluetooth. I've seen small Bluetooth receivers on circuit boards, about 1" square powered from small power supplies, wired into amps. Would it be much harder to wire it into a radio ?
Would it be possible to build a FM receiver inside this AM radio and search for stations with the radio's own dial? I have an antique AM radio but I don't want to use a stand alone FM to AM converter.
How can we know if the radio has a transformer or not? I have an RCA 4-C-544 radio but I can't find any schematics for it. Is there a way of testing for the presence of a transformer?
AM was not the only thing it could play. I got short wave on mine, but late at night, of course. had an antenna going out my window to the nearest tree. Next, I connected a 2nd speaker to the speaker...got half-cooked while doing it...those wires carry a heavy load, but eventually I got my 2nd speaker hung up over the window. Not a stereo by any means, but it was good enough for me at 13 or 14. Being located in NNY, +/- 100 miles S of Canada, 20 miles E of easternmost part of Lake Ontario and 71 miles N of Syracuse, NY, I got AM stations in NYC, Syracuse and Chicago. Don't remember other AN stations. Got a few short wave stations, but should have logged them down, trying to see if I could pull them in again, but it never occurred to me. Also got one station on the SW band that was a clock. Recorded voice (?) would tell the time every minute, but I can't remember what he said, but I tend to think this was Greenwich mean time.
Let us know if you managed to do this! Doing it to this model could be a bit tricky, because the volume control is in the RF circuits, not the audio as in most later models. You could probably put the input from the jack and resistors to the grid of the driver tube (the stage just before the push pull outputs), but the signal might not be strong enough. The tube before that is the detector, which does amplify audio, but might not sound good because it is non-linear. If you do not care for the AM radio to function, you could probably re-bias this tube for more linear operation, then the grid of this tube would be a good place to inject the MP3 signal. You could perhaps even put a switch in the detector circuit that changes the bias on the tube to work as a detector or an audio amplifier, so you could switch the functionality of it for either standard radio operation or MP3/Bluetooth/CD player input. The cathode resistor value is what you probably could switch to accomplish this- use a lower value resistor for linear audio amp operation (mp3 mode).
Yes but you would have to make sure you change the radio's switch to switch on and off the HOT side of the AC line, not the ground side. Usually it is wired in the ground side to prevent hum. Also, if you did this, you or the user would be using it at your own risk because it id dependent that the AC outlet being used is wired correctly so that the neutral polarized side is actually neutral.
Hello Terry - I am looking to "stream" music via a google Chromecast audio to my 12S267. The 1204 chassis is restored, and I THINK you did it! I've ordered 1K and 10K resistors, and 1/8 audio input and a toggle switch (to make an MP3 - Aux Input as you did - I've slowed down this video!), but I have soldered but only a cursory knowledge of what to do. After staring at old 1204 chassis schematics I came across you because... I really don't want to blow this thing up. Can you help?? Thank you in advance - Paul
Terry - I've been converting tube radios to BT using the existing audio amplification circuitry (and disconnecting the AM antenna altogether). QUESTION - Which paper capacitors should I concentrate on replacing since I'm not utilizing the RF circuitry and yet it appears that all stages/tubes are connected to each other one way or another (besides power)?
Is there any safe way to do this with a hot chassis without using an isolation transformer? I have an old hot chassis zenith and I wired up a 1/4 inch input for a guitar to it, but with the cord plugged in one way, it will be 120v on the guitar, and the other way its zero at the guitar but ONLY with the amp turned on. Once I turn the amp off it switches back to line potential.
You would have to add a polarized plug and wire the switch of the radio between the hot side of the line cord and the normal hot side of the radio circuitry. The neutral side must always be connected to the chassis ground (normally the switch is here, but replace this with a short). Make sure the outlet you are using is wired correctly by putting a meter between the chassis and earth ground when it is plugged in after modifying it for the polarized cord and making sure there is no AC voltage there.
Yes. Use a 1/4" jack instead of the 1/8". Its still an analog audio signal, so it would be handled just like the audio signal from the 1/8" jack. Its not going to be killer vintage guitar tone. Would more be just neat for novelty sake. "That guy plugged his guitar into a vintage radio!"
What's the advantage of this approach over an am transmitter/modulator? I like this better. I have an zenith 6s229 I just finished up with a fresh recap. My Volume pot is also the power switch. Is this ok? Any help would be much appreciated. Ty.
that's a nice radio. I want to add USB MP3 support to my Sony 2006/7 home amp unit. there is a module (on Amazon) that supports USB, SD card, bluetooth, but I'm not sure how to do it. the module connects to a 12v power supply and a line in.
My son and I made a radio with one of those kits. What I'd do is use the mod shown in the video, but instead of the 3.5mm jack you'll use the L and R from the amazon kit. As far as powering it. You could pick up a 12v 2 amp power supply for 6 bucks and tie it in before the transformer. Just make sure the tubes are discharged before you work on it. You don't want to get bit.
@@tlaim You might be able to use the 6.3v filament winding of the radio's transformer and add a rectifier and filer to provide DC to power the modern audio device. Perhaps adding a voltage doubler could work to get it closer to 12V if that much is needed. Although, the filament winding might have to be not grounded at one end or center tapped as it is in many cases, especially for a voltage doubler circuit.
If the phono used an additional preamp stage ahead of the normal audio amp stages for the radio function, it is possible that the guitar might work in this case. This would apply mostly if the phono had a magnetic cartridge. A few old 40s phonos did use magnetic cartridges, but very few, many used crystal ones. I had a Westinghouse that did use a magentic and had a separate little chassis with an additional preamp tube This would be great for guitar but otherwise you would have to add or build a preamp to drive the phono input of the radio.
Hello Terry, I did this modification on a "Interstate" model 68f phonograph/radio. I am pretty sure that I performed the task correctly, but I am getting radio at a very low volume when the switch is set to auxiliary. I also checked the switch with a meter to make sure the continuity was correct. Is there something else I may have done wrong since there is a sliding switch that switches from radio to phonograph? By the way I really like your videos they are very concise and informative.
If you watch the tail end of the video, Terry has this same problem too. After he sets the switch to aux input on the back of the chassis, you'll notice there is still radio bleeding through. He then adjusts the band switch on the front from shortwave to preset AM which is the "pop" you hear. This reduces the amount of radio coming through. I have a Zenith 8S563 with same mod, same problem.
Hi Edmund. I just added an AUX jack to my tube radio and am having the same issue you did -- when the switch is on for the MP3 player and the volume is turned on high, I can hear the radio coming through. I'm wondering if you ever found a solution to this problem. Please let me know. Thanks. -Mark
I can't watch it properly at the minute, but will this increase volume via mp3? We've got an old 39 radiola which we tried to add a mini jack input to (hardwired in rather than socket), but the volume on it was so low it was pointless, it was quieter than the phone. Would your circuitry here improve that? Thanks, bel
this reminds me - I've been wanting to add audio from the radio (including what I transmit). With the vintage radios, we are talking high impedance for input and output, correct?
Yes, an old tube radio volume control has a high impedance input. The output driving the speaker is low impedance due to the output transformer, but this does not matter to what is driving the input to the volume control with this mod (such as MP3 or Bluetooth receiver)
Hello, You will need to make an adapter to convert stereo to mono. You can apply the same circuit I posted, just in a pigtail cable going to a RCA plug. Using that, no internal mods would be necessary on the Hallicrafters radio.
well the radio is mono anyway..so I could just plug in the stereo coming from my music or whatever and it will work for which ever side it is hooked to right??
You need to tie the stereo 2 channel from your ipod to make a mono circuit. Due to the stereo split, If you use just the R or L signal, it will sound terrible.
Ok thanks alot...this question is off topic...but if you can look at my schematic for the SX-71 and see if you can tell me what it means on the first part of the alignment under the IF section..it is #2 to the far right..something about setting the crystal to the 455khz..could you do that please??? Thanks..
Hey, Terry from D-lab. I recently finished my first Radio. A 1941 Silvertone 7037. In the process I met Mark from Antique audio who lives right down the street from me in Plymouth, MI. He spoke of you, and I will hopefully be seeing and meeting more of you guys. I am interested in adding a jack to my Radio. So, here I go!
That is pretty sweet. I love the creativity of folks who have the ability and skills to apply that creativity.
The reason why I want to add MP3 to my vintage radio is to play old radio brodcastings through it and enjoy it with some 'Vino" like you say! :)
Thanks for the easy to understand video. I am working on adding guitar to an old tube radio. This should work easy.
I just did this to a fully restored
1937 Westinghouse 12 tube console radio. It works GREAT!! I plugged a USB rechargeable bluetooth receiver to the jack and now have both options. Brought new life back to this radio! Thank you D-Lab Electronics!
Thanks so much for posting! This is perfect for listening to my Old Time Radio shows (on an old-time radio, of course). As I type, Fibber McGee & Molly are visiting.
Thank you Terry at D-LAB! I just did this MOD on my 1939 WARDS Airline and now I'm listening to "40s Junction" on Sirius XM Radio streamed from my phone. Sounds amazing. Your videos have truly changed my life with my guitar amp & radio hobbies. I've built many guitar amps now and restored amps+radios thanks to your helpful videos. I'm enjoying this so much. Thank you again!
That is a beautiful radio... My family had one very much like. The main difference I see was that our radio had the old FM broadcast band which was 42 to 50 MHz. We spent many an hour listening to favorite shows on AM until television came on strong in the mid 1950's. Wish I still had that old trooper! 😊
D Lab! I followed your video, watched a few times over and got a stereo Jack in my 50's radio. Thank you so much for sharing your knowledge!!!
Terry,
I greatly enjoy your videos. Very few channels that I watch on youtube or that are worth watching. Yours is certainly one worth watching. Hopefully will be able to someday do this with a few radio's that I haven't gotten yet but plan to and give as gifts to my kids. They enjoy classic older radio's like I do. Guess they got that from their dad.
Keep up the good work.
Brian
This is he only video I've ever given a "like" to ever...and it's because he demonstrated with the Space Jam soundtrack.
Now that was a nice simple conversion to get your old tube radio to play MP3's Might try this on some old tube radios I am restoring thanks for the information.
Have been wondering how to do this to my late 40s Stewart-Warner floor model and here’s the answer. Thank you!
I have a 1937 Stewart-Warner console that I inherited from a great-aunt who bought it new. The thing is branded "True Value Hardware," but made by Stewart-Warner!
Awesome mod, but yet keeping it orignal. One tip too is you can buy bluetooth to aux adapters that are basically plug n play. Can add more descretion to the radio than having a aux cord hanging from it. Will be trying this, thanks for the awesome video.
You sir are what makes America great.
Cool, I have a Motorola 10T28B tube radio AM-FM with a phono input. I use an adapter that has two RCA jacks for MP3, CD, Bluetooth receiver or a turntable. I had to have it serviced a few years ago, but it is good to go and sounds even better. I can't wait to get an old RCA Victor 45 record player with a RCA phono output which is what the radio was designed to also play. Nice video!
A friend won a Discman back in the 1990s and I converted her old transistor radio to take a signal from it. The hardest part was getting a jack, the local stores had completely run out of them.
Thanks, Terry. I just repaired and recapped my first tube project. It is a GE 226 AM radio (~1950). The problem is, all the AM stations around here are talk radio! 🤨
I have the parts, so that's not gonna hold up this project.
The extra holes were there because the manufacturer used the same chassis for radio-phono combinations . Zenith radios were often better than RCA but RCA almost always included a switched phono input which would preclude the mods shown here. Experimentation with resistor and capacitor values can improve the sound quality of this arrangement if one has the time. The output of the I-pod is probably around 600 ohms while the audio line in the radio is in the 200-500 k ohm range. But it still works and those radios had a good tone control circuit which should help..
I think the early rca 45 changers had a few resistors in them for that reason
Can you show more pictures of the yellow wires going to the switch?
I was suprised that why a capicitor, somthing like 4.7 mfd was not used before 10k resistace to couple mp3 signals so that it may protect mp3 player from any AC current leakage from the radio .? Please comment
Thank you very much for this! I have the exact same radio and have been toying with the idea of adding an aux jack to the back for years. This makes it super easy since you have the exact example that I need to do this! Great video!
not to diminish at all..this mod , which is outstandingly awesome!!!!
Built this tonight and it works great!
Wow, I can imagine playing some of my old time radio theatre of the mind MP3's over a set like that. Sure wish I had the old set we had back on the farm in the early 60's when we first got electricity in the old farm house, man that would be so kool. I will keep an eye out for such a set in the yard sales of the future. Of course not a lot of space for such a unit in our Motor Home, but right now we are stranded in our Sticks and Bricks home because of illness and several recent deaths in the family. Getting old sucks!
Jerry Ericsson That’s what I did with my old 50’s console radio. It’s hard to describe the sound of the old shows on period correct systems. It’s a whole other experience with the flat booming sound yet with tube softness. Worth it.
I´m restoring a 1950s Grundig 8014 radiogram. I´ll definitely use this technique. Cheers!
I have a 1940 Emerson DS-436 I'm in the process of restoring. I never tried this before, but as this radio has a 'push-pull' 20 watt output amp, I thought I'd give it a try. It has a photo plug (not a jack), so easy to connect. I did it exactly the way you showed, but the volume is extremely low, as compared to the radio volume. I'm going to try another cord from my mp3, maybe that's the problem. Just seems like it needs far less resistance from the jack.
Found a couple of your videos really helpful. Thanks for making these. You should probably have a disclaimer on this type, there are line level voltages on some switches, and most don’t know what a hot chassis is.
Hey let's go, I have a live chassis, can I do this mod? Thanks!
I noticed your warning at the beginning...The key word is transformer. many don't realize the dangers involved in doing this mod on a series heater string AA5 :) Cool video :)
would it put high voltage on the input jack or something?
A hot chassis in the series strung AA5's can have a hot chassis where AC voltage can be present on the chassis. One side of the AC line is connected to the chassis. it can get dangerous and affect the MP3 player...
I have seen this done on an AA5. You just need to add an isolation transformer. Plus, some devices do have isolated power supplies too and these may work fine on an AA5
Isolation transformers will do the trick, however, some radios have limited interior space and there's no room to install one. you would have to have it externally.
thanks so much i just got restored 1960 ge tube radio, and wow, its so crazy to listen to cyberpunk on a 1960 radio....
loved the video and with great idea to one up a tube radio with no phono function
Great video. Just bought a nice Philco 38-15 chair side and I might do this. I transmit oldies to my radios but this is a nice option.
that clock face radio looks sweet
Hi, didn't work for me. The radio bled through to both sides of the swutch. When you say to "build up" the high side point, do we add a piece of metal to that point to GET AWAY from the high side solder point to prevent bleed through? I'm confused...
Is it chassis ground??? I see I wire going down from the jack & 10k resistor. What is that down there??
Excuse me guys but I am new to this, after digging around on the interscreen for info on a Zenith X334 and also looking inside the radio I did note that the ac power cord has one side soldered to the chassis, so in my assumption this is a hot chassis radio. Right? So my question is if I install a isolation Transformer can I do this mod to the radio using the same resistors. thanks any help would be appreciated.
Up next? Guitar amp with play along tunes? Or repurposed guitar amp. Great project with the vintage radio.
This is what people used to do to turn radios into guitar amps back in the day, I reckon.
You could also add a Bluetooth device that outputs audio into a stereo jack, connect it in this new input, this way turning your Radio into a Bluetooth speaker!
Hi form cold England I have a old rockola juke box with a stereo valve amp that uses a ceramic cartridge with a high output is it possible to get something that would allow me to play a mp3 player through the ceramic cartridge input plug I have tried it but there is no sound even with the mp3 volume turned right up barry
Thanks so much for this easy solution...works like a charm!
I have question and correct me if I'm wrong. The volume control (pot) has 3 lugs. The left pot lug is connected to the middle lug of the switch. The top pot lug is connected to the top lug switch.
My Zenith 1940 10S464 radio console has 2 pin holes and a TV/Radio switch that I use for my MP3. I have this connected to my computer and works well.
Hi I have a vox vt15 amp would it be easy to add a aux input for cd etc , can’t find help anywhere . Help please
just wandering if its easy to use an fm/am with bluetooth trasmitter just like the adapter for a car stereo to play mp3 on the radio without modifying the radio or if you just dont have the necesarry tools for the job?
Fantastic !
This is a solution I've been looking for my Zenith H503 ,provided I can find the high side on the volume potentiometer .THANKS!
Too cool. I like it! Ever work on any silvertone AM/FM radios? Got a loud hum regardless of volume can id which cap it is.
Does this work for converting to a guitar amp? But, with a 1/4 jack obviously...
Thank you i was planning to do this with my radio from my 1948 oldsmobile after i recap it and replace out of tolerance resistors
Jack Graham back when I was a kid in the late 1960s -early 1970s I drove a 1962 Dodge that included one of those "hybrid" radios with the " space charge" tubes that only ran 12v plate voltage and a transistor audio power amp. I moded that radio for an FM tuner ( those old FM to BCB RF converters sounded poor) and later for a cassette player. The fun part with the 1948 Olds radio is if it had one of those Delco synchronous vibrators. Those vibrators were problematic and not readily available today. But I hope you can get that set working. Those Olds radios were usually upgraded with push -pull audio output, a tone control that really made a difference and a better speaker. Good luc
Could I play from a rechargeable bluetooth receiver?
What "wattage" are the resistors??? 1/2 watt? 1 watt? I bought both cuz' you didn't say....
Hi there, do you by chance have a link where to order the pieces from? Thank you so much.
Wonderful mod, grateful thanks d-lab for the presentation and schematic too! I did a 1933 Majestic 461 and next will do a '37 Philco 37-630T and a '34 Zenith S-871. Makes these old gals sing beautifully.
One question though. The volume is a little weak (I use a small pre-amp to boost the iphone signal to obtain an audible level through the radio). Could I use two .5K ohm resisters on the plug to get better volume?
Can this work with 50s widow makers without a power transformer?
i have done that on a few old transister receivers and installed Blue tooth devices,one is a crosly I-Juke and my girlfriends Thomas radio and cassette took out the cassette and i can slide the smart phone in it for storage...Its alittle muddy and I see what I did wrong for got the 1 k and the 10 k's ...the jukebox is clear as a bell. .thanks..
what is the safest way to do this with a AA5 radio. these radios have a hot chassis and most of the ones I have switch the neutral wire not the hot.
Bluetooth receiver instead. That way you aren’t making physical contact with the hot chassis.
@@holmespianotuning I just did a few with an actual line input jack. I ended up using an audio transformer to create the isolation and impedance matching between the radio and the device I would be plugging in, that way there is no connection to the chassis. That is probably the only way I would trust it.
How do you add a Bluetooth to a 1930 radio with tubes
would this work for a guitar input too?
Could you give a beginner some advice on how to determine which is the high side on the volume pot?
Just test the 2 end lugs and the one not grounded is the high side.
Hello and thaks for your video!!
I have a question. You put a mensage on video:
"Caution: Do not perform this mod if your radio
does not have a power transformer!". Could you please explain why?..is dangerous for the voltage?. And if I have a radio without transformer.How is the rigth way to procede with the aux input?
Thanks!!!!
The mod is working on the Zenith 10S669 that i am working on but i need to turn the volume up all the way on the Zenith and quite high on the input source otherwise i hear a lot of static. The radio was gone through by someone else and it looks like all the parts were replaced. Maybe it is normal that it requires a high level input. The radio does not require the volume being up so high.
This is true, the voltage output of many modern devices is really not quite enough to drive the audio amp on old radios like this, at least if you don't turn the source device up all the way. Part of the reason for this is that the radio is a high input impedance device, but the modern source has a low impedance output, which means high current capability but low voltage. Putting a little transformer in between that can step up the voltage can help. A better solution could be to add a little transistor (or tube) gain stage between the audio source and the radio volume control, although this can be beyond the scope of some people who might be doing this mod. One interesting solution (believe it or not), which I have done, is get a nice cheap AC powered phono preamp, and put this in line between the modern signal source and the jack on the radio as described in this video. It will give it a bit of punch with extra bass as well, which may almost be too much, you could probably adjust the tone control on the radio to compensate for this.
Among a hundred comments .. no one has given the specs and circuit to include a capacitor of transformer to protect the MP3 player ? Can someone please do that ?
Where exactly does the center wire on the switch go to? You mentioned it goes to the volume pot but where exactly? Please help.
Early in the video he shows that connection, it's where the radio signal is fed to the pot. You disconnect that wire from the pot, attach it to the new switch, then run the wire connected to the center wire of the switch to where the wire was removed from the pot.
Thanks Jeff makes total sense now!
Nice mod...and nice MP3 player, too. I have a couple of those ZuneHD devices: a 16 gig and a 32 gig .... I love those things. :-)
Terry McKean with super woman? 😂
LOL! :-D
Nice, how about a video on converting the radio to Bluetooth. I've seen small Bluetooth receivers on circuit boards, about 1" square powered from small power supplies, wired into amps. Would it be much harder to wire it into a radio ?
Would it be possible to build a FM receiver inside this AM radio and search for stations with the radio's own dial?
I have an antique AM radio but I don't want to use a stand alone FM to AM converter.
Would you be able to post a video on how to adapt a stand-alone antique radio horn for MP3 or Bluetooth playing? Thanks!
how do you adjust the push button "auto-tune " stations?..turn the coils up and down?
How can we know if the radio has a transformer or not? I have an RCA 4-C-544 radio but I can't find any schematics for it. Is there a way of testing for the presence of a transformer?
Benjamin Engleman look for a transformer connected to the mains input on the chasis.
AM was not the only thing it could play. I got short wave on mine, but late at night, of course. had an antenna going out my window to the nearest tree. Next, I connected a 2nd speaker to the speaker...got half-cooked while
doing it...those wires carry a heavy load, but eventually I got my 2nd speaker hung up over the window. Not a stereo by any means, but it was good enough for me at 13 or 14.
Being located in NNY, +/- 100 miles S of Canada, 20 miles E of easternmost part of Lake Ontario and 71 miles N
of Syracuse, NY, I got AM stations in NYC, Syracuse and Chicago. Don't remember other AN stations. Got a few short wave stations, but should have logged them down, trying to see if I could pull them in again, but it never
occurred to me. Also got one station on the SW band that was a clock. Recorded voice (?) would tell the time
every minute, but I can't remember what he said, but I tend to think this was Greenwich mean time.
This same principle should work in a Leslie Organ amp also, right?
Can you do the same type of mod to an AA5 radio?
Awesome video, would this method also work on newer radios? I have a late 80's G.E. portable radio I would love to do this on.
Very cool!! I will have to convert my old Atwater Kent 55C radio.
Let us know if you managed to do this! Doing it to this model could be a bit tricky, because the volume control is in the RF circuits, not the audio as in most later models. You could probably put the input from the jack and resistors to the grid of the driver tube (the stage just before the push pull outputs), but the signal might not be strong enough. The tube before that is the detector, which does amplify audio, but might not sound good because it is non-linear. If you do not care for the AM radio to function, you could probably re-bias this tube for more linear operation, then the grid of this tube would be a good place to inject the MP3 signal. You could perhaps even put a switch in the detector circuit that changes the bias on the tube to work as a detector or an audio amplifier, so you could switch the functionality of it for either standard radio operation or MP3/Bluetooth/CD player input. The cathode resistor value is what you probably could switch to accomplish this- use a lower value resistor for linear audio amp operation (mp3 mode).
Could you do this to a hot-chassis radio IF you also installed a polarized AC plug, so that the chassis was never connected to the hot side?
Yes but you would have to make sure you change the radio's switch to switch on and off the HOT side of the AC line, not the ground side. Usually it is wired in the ground side to prevent hum. Also, if you did this, you or the user would be using it at your own risk because it id dependent that the AC outlet being used is wired correctly so that the neutral polarized side is actually neutral.
Getting parts now. What is the wattage rating of the resistors?
1/2 watt
Hello Terry - I am looking to "stream" music via a google Chromecast audio to my 12S267. The 1204 chassis is restored, and I THINK you did it! I've ordered 1K and 10K resistors, and 1/8 audio input and a toggle switch (to make an MP3 - Aux Input as you did - I've slowed down this video!), but I have soldered but only a cursory knowledge of what to do. After staring at old 1204 chassis schematics I came across you because... I really don't want to blow this thing up. Can you help?? Thank you in advance - Paul
super cool! thank you for all the vids!
Terry - I've been converting tube radios to BT using the existing audio amplification circuitry (and disconnecting the AM antenna altogether). QUESTION - Which paper capacitors should I concentrate on replacing since I'm not utilizing the RF circuitry and yet it appears that all stages/tubes are connected to each other one way or another (besides power)?
Awesome vid, thanks for sharing.
can this be done to an old 5 tube transformerless radio? like the plastic admirals etc?
I would not recommend it, since the chassis is hot.
It would be safer to get an AM transmitter and just broadcast the mp3 player on some unused frequency.
Nice job Sir 👍
Great Video! Any advice or chance of a video on installing a switched Mp3/Aux and Guitar port for a tube radio? 😊
Is there any safe way to do this with a hot chassis without using an isolation transformer?
I have an old hot chassis zenith and I wired up a 1/4 inch input for a guitar to it, but with the cord plugged in one way, it will be 120v on the guitar, and the other way its zero at the guitar but ONLY with the amp turned on. Once I turn the amp off it switches back to line potential.
You would have to add a polarized plug and wire the switch of the radio between the hot side of the line cord and the normal hot side of the radio circuitry. The neutral side must always be connected to the chassis ground (normally the switch is here, but replace this with a short). Make sure the outlet you are using is wired correctly by putting a meter between the chassis and earth ground when it is plugged in after modifying it for the polarized cord and making sure there is no AC voltage there.
Thank you for this mod, now I can play Russian Number Stations late at night to freak out my sister.
Like the way you think...9..7..4..8..2..2..2..2..3..4.2.. Short wave radio is just fun, fun, fun.
I'm am looking to take a tube radio and convert it strictly as a guitar amp. There is not very many in dept videos could I use this mod to do so?
Yes. Use a 1/4" jack instead of the 1/8". Its still an analog audio signal, so it would be handled just like the audio signal from the 1/8" jack. Its not going to be killer vintage guitar tone. Would more be just neat for novelty sake. "That guy plugged his guitar into a vintage radio!"
What's the advantage of this approach over an am transmitter/modulator? I like this better. I have an zenith 6s229 I just finished up with a fresh recap. My Volume pot is also the power switch. Is this ok? Any help would be much appreciated. Ty.
Well, an AM transmitter will run about $170-$200. This runs about $5-$10. Also with this, you could plug in a Bluetooth receiver.
that's a nice radio. I want to add USB MP3 support to my Sony 2006/7 home amp unit. there is a module (on Amazon) that supports USB, SD card, bluetooth, but I'm not sure how to do it. the module connects to a 12v power supply and a line in.
My son and I made a radio with one of those kits. What I'd do is use the mod shown in the video, but instead of the 3.5mm jack you'll use the L and R from the amazon kit. As far as powering it. You could pick up a 12v 2 amp power supply for 6 bucks and tie it in before the transformer. Just make sure the tubes are discharged before you work on it. You don't want to get bit.
@@tlaim You might be able to use the 6.3v filament winding of the radio's transformer and add a rectifier and filer to provide DC to power the modern audio device. Perhaps adding a voltage doubler could work to get it closer to 12V if that much is needed. Although, the filament winding might have to be not grounded at one end or center tapped as it is in many cases, especially for a voltage doubler circuit.
Hi, i have 46-1209. I took the 78 player out. Can i repurpose that input for a guitar? I beleive it goes right to a preamp tube. Thanks
If the phono used an additional preamp stage ahead of the normal audio amp stages for the radio function, it is possible that the guitar might work in this case. This would apply mostly if the phono had a magnetic cartridge. A few old 40s phonos did use magnetic cartridges, but very few, many used crystal ones. I had a Westinghouse that did use a magentic and had a separate little chassis with an additional preamp tube This would be great for guitar but otherwise you would have to add or build a preamp to drive the phono input of the radio.
outstanding. this was a perfect video
Hello Terry, I did this modification on a "Interstate" model 68f phonograph/radio. I am pretty sure that I performed the task correctly, but I am getting radio at a very low volume when the switch is set to auxiliary. I also checked the switch with a meter to make sure the continuity was correct. Is there something else I may have done wrong since there is a sliding switch that switches from radio to phonograph? By the way I really like your videos they are very concise and informative.
If you watch the tail end of the video, Terry has this same problem too. After he sets the switch to aux input on the back of the chassis, you'll notice there is still radio bleeding through. He then adjusts the band switch on the front from shortwave to preset AM which is the "pop" you hear. This reduces the amount of radio coming through. I have a Zenith 8S563 with same mod, same problem.
Hi Edmund. I just added an AUX jack to my tube radio and am having the same issue you did -- when the switch is on for the MP3 player and the volume is turned on high, I can hear the radio coming through. I'm wondering if you ever found a solution to this problem. Please let me know. Thanks. -Mark
I know this has been out a while but I am curious if you ha e done anything like this to use a Bluetooth receiver???
Yes...just added a TaoTronic USB rechargeable bluetooth receiver plugged into the jack. Works great $15 on Amazon.
I can't watch it properly at the minute, but will this increase volume via mp3? We've got an old 39 radiola which we tried to add a mini jack input to (hardwired in rather than socket), but the volume on it was so low it was pointless, it was quieter than the phone. Would your circuitry here improve that? Thanks, bel
If you do this on a transformer less AA5, could you damage your MP3 player?
I would not do this mod on a hot chassis radio. Good call. Thanks for bringing that up. TD
+D-lab Electronics You could always throw in a small isolation transformer. BTW more dynatones pls
Roger that man, I added a caution note to the video
Hey Terry what wattage are the resistors you are using, and does it matter ?
Why you never clean the radios
this reminds me - I've been wanting to add audio from the radio (including what I transmit). With the vintage radios, we are talking high impedance for input and output, correct?
Yes, an old tube radio volume control has a high impedance input. The output driving the speaker is low impedance due to the output transformer, but this does not matter to what is driving the input to the volume control with this mod (such as MP3 or Bluetooth receiver)
How about a hi-fi record player?
CAN YOU INSTALL THIS IF I SEND YOU MY CHASSIE...
I have a Hallicrafters SX-71 and it has a phono setting, and the rca jack on the rear...can i connect it straight, or do I need the resistors...
Hello, You will need to make an adapter to convert stereo to mono. You can apply the same circuit I posted, just in a pigtail cable going to a RCA plug. Using that, no internal mods would be necessary on the Hallicrafters radio.
well the radio is mono anyway..so I could just plug in the stereo coming from my music or whatever and it will work for which ever side it is hooked to right??
You need to tie the stereo 2 channel from your ipod to make a mono circuit. Due to the stereo split, If you use just the R or L signal, it will sound terrible.
Ok thanks alot...this question is off topic...but if you can look at my schematic for the SX-71 and see if you can tell me what it means on the first part of the alignment under the IF section..it is #2 to the far right..something about setting the crystal to the 455khz..could you do that please??? Thanks..
Would this work for guitar 1/4" input as well??