Stereo to Mono DIY cable to connect music player / iPhone to tube radio.
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- เผยแพร่เมื่อ 28 ส.ค. 2024
- Stereo to Mono DIY cable to connect music player / iPhone to tube radio.
A quick look at how to build a good stereo to mono converter cable, that is more than simply a Y-cable that is often suggested on the web.
In most tube radios you can use the Pickup (gramophone) input to play your music player or iPhone through. These old radios usually produce very good sound, with some having an impressive array of speakers in beefy wooden cabinets that will fill your room with bass. The PU input lets you use them as an amplifier and speaker system in one, for your favourite music source.
The challenge is that they normally have two sockets at the back for your input, one being the Signal (mono) and the other the Ground. Normal 4mm banana plugs usually fit so we need to doctor our cable a little.
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Why is nobody talking about the fact this guy rips Wire apart without using tools. Just digs in like a bear. You, sir, are legend.
Thank you for teaching an old dog a new trick! I had never seen anyone make connectors by wrapping wire like a spring! That was brilliant!
He is a tube guy... That is a neat trick used in point to point connections of tube circuits. :-)
I don’t love dealing wire wrapped terminals in components (receivers, etc.), but I love how you use the technique to join those wires. Brilliant and well done as always.
thanks
Just came across this video. Man, I love your short clear talk (unlike some tubers who talk on a on while holding something in front of the camera and wiggling and shaking it endlessly with their fingers ......you get dizzy just watching it) and the neat and meticulous way you do the wire connections....very pleasant and fun to watch
Glad you liked it.
Never too old to learn a new trick! I love how you create these 'wire wrap terminal connectors' to join two wires, excellent tip, never thought of that before. I landed on your channel because of the Graetz radio restoration. I remember we had this Graetz Melodia m618 when I was a kid. Unaware of the dangers of high voltage I played with it connecting other equipment to it. Fortunately there was never an accident... These old radios are gems of that era and it's great to see them being restored and even being used with our modern equipment!
I too remember playing with one of these tube sets as a kid, and was lucky as well 😊 no shocks that I can remember.
Enjoy the channel.
When I was a youngster we had an old valve radio rather like this and it inspired me with a great interest for all things to do with radio and electronics, which I still hold to this day. How nostalgic to see such a fine example of a typical radio set from that bygone era. I also appreciate your guide to making a "summing lead" of which I have made a few similar examples myself for my various musical electronic devices with stereo outputs to play into mono line inputs. I also recently developed a "summing input box" for connecting up to 5 stereo inputs from different instruments which are individually summed and then fed into a single summed output into a mono line input on a keyboard. The keyboard then acts as the DSP effects processor and amplifier for the audio input from the 5 devices as well as me playing the keyboard with its own sounds, all through the built in keyboard speakers. Many thanks for your "trip down memory lane" and your electronic expertise and elaborate explanation. Please keep up the good work.
Thank you for you kind words. I’m happy to know that my videos inform and inspire. Ultimately, that was my prime reason for the channel.
Great video Manuel, thank you! An idea to make the resistors make a little less of a bulge is to make the cable of one channel slightly longer than the other one so that when one resistor ends the other one starts so the total thickness is reduced to a resistor plus the lead instead of two resistors. Keep up the great work!
Thanks for the tip.
Thank you, thank you, thank you. At last !. Why was this so difficult to find. Wanted to do this for ages, but it was like trying to find The Holy Grail.
Glad to be of use to you. My pleasure.
Tks for your video. Here in Argentine, we call plug at the object you call " jack"
WOW I watched this video to see if you were going to do something different than 2 resistors. I'm going to add a Bluetooth board to a 1946 phono input. But your assembly technique is AWESOME how is it that I've been doing electronics stuff for 40 years (off and on) and have never seen this method of hard wiring it's sort of a half Western Union. You have nice skills truly professional results. Thank you for that simple technique.
My pleasure, Joe. Glad to be of some help.
@@electronicsoldandnew I'm just amazed I've never seen that technique... Thanks
pleasure
Did that work?
@@uscroger4690 yes th-cam.com/video/fyEbBoBcc8s/w-d-xo.html
So true! Twisting L and R together is not the way. Great video again!
Thanks
Nice project, I need to build one of these. A couple of comments: 1. If one has a hot air soldering station, they also make a great heat shrink tubing heat source for small jobs such as this - plus no open flame on the heat shrink material, a pet peeve of mine. 2. As you correctly pointed out, for a variety of reasons line voltage may be present on the chassis ground of a radio. Using "screw type wire retainer" banana jacks is something I would discourage as line voltage could be present on either of the plug's screws and there is a high chance that a person will place a finger or thumb directly on an exposed screw head when inserting or removing the plugs from the radio. Using solder type plugs with no exposed metal surfaces is a wise choice, IMHO.
Great ideas. Thanks 😊
Great idea, build one while watching your video, now my old Radio has is even better audio quality, i was using a FM to Am converter before this Bluetooth mod
Great.
What an informative video. Learned all sorts of tips and tricks. This was exactly what I’ve been searching for. Thank you.
Gavin Ivey : you’re welcome.
Very nice and simple tutorial demonstration how to connect a modern equipment like I.phone ecc. To an old tube amplifier radio connection by preparing the right cable to the radio. This type of cable doesn'exist yet. I think you could patent it. Thanks for the video.
Thanks so much! I intend to build a stereo 1/8" to RCA mono to use with a chromecast audio into a Knight integrated amp. I will certainly be sure to check for a hot chassis, but I am confident this is not the case.
I especially like the way you shielded the signal all the way to the splice and I learned a few tricks for soldering bare wire. I need to get some of that steel wire on a spool, for sure!!
William Smothers : always a good idea to check. Have fun.
Thank you Sir you probably saved me a repair from a damage amp!
👍
Its all about having the right tools and materials.....This would take me 3 days to do
Makes all the difference.
A cut down biro /Felt tip pen with heat shrink over it works well BTW
Coming back to this old video because of something I saw today. The claim is, this kind of stereo to mono conversion, although it keeps the source device perfectly safe, it rather creates a very wrong mono impression of a stereo source. The problem is defined as; this being a voltage divider, it works perfectly as long as the audio in both channels are almost identical. But when one sound is present in one channel and totally absent in the other (i.e. one instrument or voice is panned all the way to left or right) then the absent channel becomes a sink to the other and the panned sound is halved in the divider, thus creating a "wrong" mono mix. The claim is further extended that there may be situations where a signal on one channel can actually cancel another one on the other channel if by chance, they happen to be very similar but 180 degrees out of phase... This is splitting hairs, I know but there is a sound logic in it too.
There is logic, indeed. The only way to really “sum” the signals would be by using opamp adder, but even then some out of phase signals could cancel out. This is really a simple and “good enough” solution, but by no means perfect.
80% of all the sales made today through electronic radios and such are made on AM (and possibly FM) Radio! This may surprise some people, but that is what the statistics show.
That is surprising.
@@electronicsoldandnew It is amazing how many products (especially medical) are sold through various programs all on AM radio bands over the weekend and even during day and nighttime hours.
This includes all the radio talk shows which advertise discounts if you use their name on various products such as vitamins ect. and all these shows are on AM radio 24 hours a day, especially in California with radio shows having a National hook-up. It is astounding how many products are sold from advertisements on AM radio bands!
I have heard them use that 80% figure oftentimes when listening to the radio. The 80% figure may not actually be that high, but there is a lot of money made through these various advertisements.
Cool! Thanks for the clear explanation as well as demonstrating how to do it!!
Glad you liked it
Thank you so much! Brazilian cheers.
Glad you posted this because the information on the Internet today is indeed "FLAKEY"!
True.
This is a HUGE help on a couple of my old tube radios but a few others don't have that banana style plug, they have an early type 3 pin DIN plug.
Whilst I imagine the 3.5 jack end of the cable is the same I have no idea how the 3 wires in the DIN plug are orientated.
In some cases they are not standard, so you'll have to open it up and actually check on the back of the socket just to be absolutely sure.
Came here for exactly the same reason re the later 3 pin DIN plugs on slightly later valve radios.
Did you follow this up and work out how to wire the 3.5 jack plug into the 3 pin DIN connector using the resistors Manuel uses here??
You sound South African. 👍🏻😁 I have learned quite a few tricks. Thanks boet.
I grew up in SA, hence the accent. Grew up in Harrismith and then PMB. Studied in Durban Varsity. Where are you from?
@@electronicsoldandnew Small world. Grew up in Greytown in the 60s and 70s. Studied sound engineering at SABC in the 80s. Spent most of my life in Joburg. Now back in Kzn, Camperdown. Tinker with building hifi systems that sound amazing on small budget. 3D printing and basic electronics sometimes play a part.
Where are you living now?
In Madeira.
If I’m not mistaken, the de Jesus family still live in camperdown. They are also madeiran.
@@electronicsoldandnew I've only been here since May an Covid 19 has not allowed me to meet many people. I will keep an eye out for them. My sister is living in the Azores now. I'm hoping to visit there soon. To be honest I think it is time for me to start looking at my options abroad. Thanks for the response and the really good videos. The level of detail is perfect for someone like me with very limited knowledge. I'm currently attempting a project to make wireless active speakers with 2 x bluetooth modules. Hold thumbs.
Thanks for the video. I will try yhis Sir. May God Bless
👍
I do this the lazy way and wire one channel of the stereo 3.5mm cable to the output jack then set my iPod to mono. Good call on the hot chassis. Many US sets are hot and can be dangerous if someone is used to newer electronics.
Jim Kresky : Yes, that is a good method.
Hot chassis are a menace, and I’ve come across them in Portugal too. I guess they were a cheaper option, so sold well here. We use 240v mains, so a zap is even more memorable.
Thanks so much for your help love the way you make your connections meny thanks Mike in England 😁
My pleasure
Thanks, very usefull! Got 60 old radio's to play with, so.......
Wow. You're worse than me.
Nice video. Is there a safe way to do this with a hot chassis in Canada with a neutral outlet?. I changed the wall plug of my Philip's P143 to orient neutral to ground. Added a speaker out and added a microphone/guitar/bluetooth jack input to the volume pot where the RF was connected. Recapped. I added a cooling fan as it's overheating. Also the mic input maybe to strong relative to the Rf input . It sounds very good as a harmonica amp so I'm motivated to make it safe.
There is a way to do it safely using capacitors to isolate the input, but I cannot give details as it may hurt someone 😊
I would use an audio isolation transformer mounted inside the radio and connected to the input jacks. This would prevent the grounding problem you mentioned in the first part of the video. Added protection for your mp3 device. You can get 5 of them for less than a few dollars on ebay.
Joseph Nicholas : true. That would work well.
Good solution. Can you please give more details about the type of transformers you used or a typical ebay link? Thanks
esmail Just search eBay with the search term ' Audio Transformer 1:1', you'll find lots of them
(typically in red tape wrap). They are cheap, but effective. I've made hum destroyer boxes for laptop to amp
solution.
@@standishgeezer: Great. Thank you very much for letting me know.
On 2023. I have an opus telefunken. Will this work?
Thank you
pleasure
Nice...
Thanks
Very nice and simple tutorial way ;
Great info!!!
👍
Brilliant,thank you!!
John Kennedy : my pleasure.
thank you
you can explain very well
+Ilona Philipp : thank you. Hope it was helpful.
Well done !
MrFreakwent : thank you.
Excelente!!!!!! Gracias por la idea!!!!
mi placer
thank you for this awesome video
+mountainhawk : you're welcome.
nice one Manuel.................Berni
+berni ken : thank you
Hey I got a Sony mhc ec79i won't turn on and has a protection mode on it and a timer thing that's broken as well on the bord part
I have one other question if you don’t mind. It’s more specific to this video’s topic of going from stereo to mono. Instead of a headphone output the source I would like to use is stereo turntable with magnetic cartridge into a mono Blaupunkt radio. I plan on going from turntable to preamplifier to the radio’s inputs. My question is this: are the 1k resistors still the correct choice for mixing the signal?
If you’re going from stereo to mono, yes.
The inputs of this old tubecracker are for the turntables with cristall-systems. Isn't that a problem, because these have a high output-impedance?
Btw: On the market there are very little af-transformers. These can be used to get rid of the problem with the 'hot-chassis'. Cheerio.
Thanks for this!
Nick Trousers : you’re welcome.
I think you are making things here more complicated as they need to be:
a) set your sound source to mono output and use a single channel
b) solder a wire with 3,5 jack to the insides of a radio you intend to use for external sound sources
c) such jigs are not the only reason you have to take care so the chassis is not live (if you want to install an earthed connection it's a must) . For regular use it's probably not a bad idea to add an isolation transformer, either internal or external (and make a power plug in such a wa that it can only be plugged in it, eg. an aviator plug)
Great video! Could you do this same procedure but from a stereo 1/8 inch to two 1/4 inch guitar jacks as well? Like from the Spark 40 headphone output to two Headrush FRFR 108 powered cabinets? If so, would you use the tips of both the guitar 1/4 inch jacks or would you use one tip for the signal and the shield on the other for the ground?
A bit of a off-topic question... You live in Madeira (and I envy that) Your name suggests that you are in fact Portuguese, but your English is exceptionally flawless, accent and all, how come?
Bora Yurtoren : grew up in South Africa.
I am deaf in one ear and want to make this cable but with both ends being a 3.5mm jack, so that I can have downmixed mono output for my headphones. Would I just solder both wires from the "output" end onto the connected resistors?
Yes, each one through its own resistor and then they join as the Mono output.
Thanks for the video. I have a question. I’m trying to connect Braun Atelier to a bluetooth receiver. Do I use a mono cable or stereo cable (3pin DIN- double RCA)for Atelier?
The atelier has stereo external input, so use stereo.
After discussing the potential for a hot ground I thought you would add an isolation transformer.
Lewis Burmeister : going that route gets pretty expensive fast, especially if you want good sound quality out of the thing. If you have a hot chassis radio, you definitely can't use this option safely. There are alternatives which I'll probably cover in future videos.
Thanks for the great video!
if I have a stereo cable (4 wires: left, right and 2 ground) how can I connect it to this mono amplifier board that has ground , + and - wires?
thanks 🙏🏻
The two grounds are wired together as one.
@@electronicsoldandnew yes this is understood, but how I connect this 2 ground and left+right wires to mono amplifier that has only 3 wires: +,-,g ?
Thanks I came looking how to take the stereo headphone output from my mums TV to a speaker on the shelf next to her. Can this lead go into a small speaker (I expect some loss as its a 3 meter run)?
I may have to put the speaker to one side and buy a small beatbox that has a stereo jack input.
Not much loss at that distance.
High from England I did enjoy this video I will be doing something similar but I need to put the signal into a stereo valve amp on my jukebox I will beusing a 2 channel passive di box as the only input is where a ceramic cartridge plugs in but not sure if I can join both channels on the input to the stereo amp
take care in this worrieng time barry
So what kind of a resistor would you recommend for a low impedance load like a pair of antique mono headphones? I have a friend who wants to connect his iPhone to his antique headphones. I have all of the proper connectors and I know about the resistors but I’m just not sure what the value should be.
Not sure, actually. With low impedance headphones you’d lose most of the signal with the resistors I’ve used. I’d try 100 Ohms and see how it sounds
Nice, thanks! // Muito bom, obrigado!
Prazer
On some articles I found, there's a resistor between the gnd and the summed output - on some cases, 1K up to 10K. Also, in theses articles, a 220 or 470Ohms resistors are used for the summing circuit. Could you elaborate on these observations? BTW, I'm making a cable to connect a electronic drum (Roland TD1) to a cheap bass amp. Thanks!
Really nice trick wrapping the wires like a spring!
The resistor to ground forces a ground reference when the summed output is not connected to a ground referenced input. It can avoid spurious dc levels on the output when not connected. Does no harm, as long as it is relatively high - I’d go with a 22k or higher.
The summing resistors can be lower than the 1k I suggest and should make no difference as long as the ground ref resistor is high as suggested, because it actually creates a potential divider which drops the signal level accordingly. Too low and you can get interference between the two output devices.
I realize that this is an older video but wanted to ask a question. You pointed out the "hot chassis" issue to be conserned about but did not provide a way to protect against this. Just wondered if you had a design for this or not. I have my own idea of what would work but wondered what your thinking might be.
I’ve done a few, but this one is my favourite:
Hot Chassis Plug - with LED indicator for hot chassis tube gear.
Hi, Thank you for this video. I am using the principle for making a bluetooth active speaker from an old passive speaker. The bluetooth stereo signal will be passed to a mono amplifier to feed the music to the speaker. Maybe I am having a blond moment but I have a question where to look for the iron/copper(?) wire you use to make the 'spring connector' (at 19min30s in the video) when you solder 2 wires. I try to find that type of un-isolated wire but can't seem to find it. What should I search for? What diameter is it and what material? I can find iron binding wire but that is way too stiff and probably too thick. Thanks for enlightening me... :)
it’s 0.8mm wire. get it at any electronics store.
I've come back to this with a question.
In the video you state that mono is usually the upper orifice on the rear phono input of the radio and Ground the lower. Obviously this is a vertical input.
On most of my German sets have a horizontal input on the back but also a smaller hole in the centre of the two (banana) orifices for what I assumed was the ground.
I have recently used a makeshift 3.5 jack stereo cable and can get music through the phono facility with the ground or signal in either "banana" hole of the phono input and nothing in the smaller centre hole. I'm just wondering if it makes any discernable difference as I cannot tell a difference in the audio quality.
Thank you also for this video and the (as usual) crystal clear explanation for the two 1k resistors. I shall be doing that myself now.
The ground socket/signal socket orientation can vary from set to set, so you need to check the marking on the back cover. If there are three sockets, the my guess is that it’s for stereo input.
@@electronicsoldandnew
I think he is talking about that thin orifice that you almost appear to be putting the signal banana plug in at 23m50s on your video.
I also have a few radios with the thin orific between the banana plugs.some vertical some horizontal.
Epic. Can I easily adapt the ohms for amped signal going straight to a speaker? Many units will have two amps (L+R) to take advantage of.
No. If I understand your question correctly, you’re talking about the amplifier output signals. This will not work there. It’s purely to join line level signals - small signals - not high power ones.
@@electronicsoldandnew ty
👍
Great information, thanks for posting. I have a question about a vintage single speaker device (not powered at all) that I want to use with an iPod or similar input. My thought is to mount a 3.5mm stereo jack to the device so that you can simply connect from any stereo source with a common stereo cable, then following your connection diagram from there so that everything is enclosed within the device. Basically, what you did but from the connector forward to the speaker. Do you think this will work or am I missing something?
8alonzo8 : yes, you’re missing an amplifier. The output from your iphone is too weak to drive a speaker. Only headphones. You can add one of those small power amp modules, and then you’re ok.
Manuel
I am attempting to fit a Blue Tooth board like the one you use to some of my radios.
With the Beomasters I have, I can easily plug in a commercial 5 pin plug with its 2 shielded wires one for left and one for right channels. (The left and right hand signals come out of different sides of the 5 pin din connector). There may be 2 sockets on the Beomaster with one for receiving turntable signals and one for tape connection and corresponding switches to select these sockets. I have used this with Logitech blue tooth adaptor and it is simple to use and works well.
I thought that connecting the mono radios I have (Beolit 600 and Grundig Party Boy and Grundig Satellite 2100) would be as simple. However I am struggling. I have made up the lead you suggested with the 2 resistors and just to get it working I used a bench power supply to power the board (3.7 to 14.3v) and I used 9.5v. Now the Grundig and the B &O have similar connections on the 5 pin connector. The B&O just soldered 2 pins on each side of the plug together. The Grundig appears to have a ground on 2 of the pins 3 and 5 with a resistor on one side and on the other side of the plug the 2 pins 1 and 4 are joined with a resistor. This is marked for turntable on the schematics. This leads via a switch to the preamp and amplifier stages when the push switch is depressed. I cannot get any signal from the board, all I get is a hum. It is much the same with the B&O
I was wondering if you had fitted blue tooth to your Grundig 2100's and if so was there something that I have done wrong?
Help would be much appreciated.
John
I have not fitted BY to my Grundig. however, the 2100 input DIN socket has input from an external source and also an output to a tape system for recording, in the same DIN. You need to connect the two outputs from the BT (L and R) through two 1k resistors to get mono, then connect this mono signal to the input pin on the DIN connector, and obviously Ground as well. I’m not sure which side is input and output, but try both and you’ll see the result.
@@electronicsoldandnew Manuel Sorry for the delay. I have it working, I have tried both sides of the din plug and have it working on either side. The sound from the iPad is a bit disappointing. The sound comes over to the radio as a quiet signal and lacking in bass. With the bass turned up max and sound much higher than I usually set it at the result is listenable with no obvious noise. However it is disappointing. The fantastic quality sound of the Satellite 2100 is just so good on FM anything worse is soon noticed. I did try playing with the iPad settings and note that there are Apps that correct the problem. I may well try another bluetooth board to see if it is any better. John
If you connect to the tape out of the din socket, all the bass will go away, so you may have it in the wrong side. There is a high value resistor in that line that acts as a high pass filter. Try the other side.
@@electronicsoldandnew Thanks for the reply, I did try both sides of the din and there was a difference as you say. The signal is just too low and lacking in Bass. John
Manuel
Finally found the issue and fixed it. Both sides of the din socket have 1 150K resistor fitted on the IM AF board (R571 and R573. ) R 571 was the easiest to get at without having to take the chassis out and I desoldered the resistor and fitted a wire link across it. This cured the problem. I now get reasonable volume with the iPad and radio volumes at 50% volume. The bass is now strong.
Thanks for persevering with me. A happy John
Thanks for the video. I am wondering if you have any updates for isolating hot chassis apart for the isloated transformer idea given by Joseph Nicolas.. Thanks
esmaeil nam : his idea is still the best as any other solution can put your equipment and yourself at risk.
Very clear explanation. Thank you. I need a stereo to mono lead for my stereo guitar to mono amp. Presumably this would work. Can you recommend what resistors I need?
williamshywel : yes, will work. Use two 1kohm resistors.
Can i use 1.8k ohms ¼w, 5% resistor as an alternative?
that will work too
Excellent video from one old fart to another. All I get are eye-rolls from the kids when it comes to this hobby.
My daughter used to do the same thing, until i added bluetooth to one, and then she wanted it for her room. Dad suddenly became cool.
RCA Jacks will not work on all radios.
Excellent I want to do the reverse,I want to mix L - R to mono I’m deft in left ear and want sound for helmet R channel!
If you’re mixing two stereo channels, they produce the same result.
I have the Grundig 4006u with the 5 pin din port. Can you please tell me the resistor arrangement if I wanted to make such a cable? Thank you.
Resistor arrangement is the same if you want Mono. Then you need to see which pins are the input, which is different for every radio, so i can’t help you there.
@@electronicsoldandnew Thanks so much for your time. Love your channel!
Pleasure
Hello from Michigan! Thank you for your very detailed videos. I am finding them extremely helpful. I have 2 quick questions regarding stereo inputs for you. I have a Blaupunkt Arkansas de luxe 40323 which is a stereo unit. It has a 5 pin din for the tape input. I am currently using a 5 pin din/RCA adapter to connect my Bluetooth device to this input. Do you see any problem with that?
The unit also has a 3 pin din as the phonograph input. What is the most appropriate way to adapt 3 pin din to RCA? Thank you!
I don’t believe there is a standard way to adapt these sockets as in some instances the convention may not have been followed. I’d suggest actually looking at the socket on the inside and see where the wires are soldered to. That way you’re sure to get it correct.
@@electronicsoldandnew Ok got it and thank you for the reply!
@@electronicsoldandnew I checked and they are wired exactly as expected. 5 pin: 1/4=R/L out, 2 ground, 5/3=R/L in. So since I’m going from stereo to stereo my RCA to DIN adapter should be safe to use, yes? I’ve been using this already and the sound is great with no known issues.
The 3 pin is 1=R in, 2=ground, 3=L in. This one more my concern. Again since going stereo to stereo am I safe to make an adapter by taking the individual RCA grounds and wire them in common to the DIN ground? The turntable itself is already self grounded FYI.
Yea, that’s the way to do it.
@@electronicsoldandnew Thanks again!
does this work for downmixing two mono channels into one mono channel? for example, combining audio from one MP3 source and another from a lavalier mic?
Those two are completely different levels, so that won’t work.
do the coils have any inductance
which coils?
Why do resistors work here since they (only?) cause a voltage drop? I would have assumed that diodes would have been put instead of resistors so as to prevent reverse current flow.
The idea is not to prevent “back flow” of current, because we’re dealing with AC signals anyway and don’t want to rectify them, which would happen if you use a diode. The purpose is to add the two signals together, which happens with the two resistors as connected here. This makes the two signals sunk to one, and prevents the two driving sources from fighting each other.
So ... resistors lower the max. combined votage ... which lowers reduces/prevents distortion caused by too high vptage peaks?
Do you have a similar video for connecting to a 1/4" mono male in lieu of banana plugs?
Sorry, I don’t.
Will this work on my telefunken opus??
It should
Great tutorial
one Question. If you're not sure you're dealing with a 'hot-chassis' ... how do you test it?
Just look for a lower transformer. If it’s not there, it’s a hot chassis set.
@@electronicsoldandnew ok, I see a big transformer, so I shoul be allright.
It should have two transformers. A power transformer and an output transformer.
@@electronicsoldandnew IS this aa good way to measure a hot chassis?
th-cam.com/video/tlLMHjWDJfc/w-d-xo.html
So 1 to groud, the other to the chassis?
First of all, thanks for the video. I have a question. What happens if we played Bohemian rapsody? Especially "...little high, little low..." part - as sound goes different channels completely?
barış Tatar :in mono it becomes one channel, the sum of the two stereo signals.
Can you please check this video for me? th-cam.com/video/p1xNbFQ9zRE/w-d-xo.html
Never solder a multistrand wire that you are going to clamp. The solder creeps and the connection will become loose in time. Ask me how I know.
😊
Excellent. Thank you. I have a question. I am currently restoring a Grundig 2420 U. It has a 5 pin DIN for the PU switch. It has a 2.2 meg resistor in series with a .0033 cap goin to pin 1 to the off switch. Pin 3 and 5 go directly to the PU switch. The question is, is 1 K a high enough value to put in series with the output of my iPhone or IPad?
Raul Montesdeoca : the signal has to go into 3 or 5 as a mono signal, with the other connection needed being ground. The resistor and cap to pin 1 is a tape out signal, so don’t connect anything to that.
Electronics Old and New by M Caldeira thank you very much.
Great video ! do you not put a capacitor after the resistors for added protection, decouple it from the radio. I was advised this is GD idea ? Cheers
+Kye Robinson : you can and it does add some protection against DC, but generally I don't use one. I guess it probably is a good idea though.
@@electronicsoldandnew if you add a capacitor where would that be connected in the diagram and what value would that be. thanks
crfmusician : between the signal in and the input socket at the back of the radio.
Dear Sir, I have the Philips B6CA37A Bi-Amply radio with 800 Ohms speaker. (output transformer less radio) . Is this radio with hot chassis? Can I use this stereo to mono cable with 1k resistor? Kindly let me know. Thanks and best regards.
Check the schematic. I don't have that radio.
@@electronicsoldandnew Ok will check. Also please clarify for: are these 1K 1/4watt resistors of Metal Film Resistors or Carbon Film Resistors or Wire Wound Resistors? Which one should I buy? Kindly let me know. Thank you.
Sir, If you don't mind, again I would like to ask you for one more: This cable you made for mobile phone or iPod with 1K ohms resistor. If I have to use a CD player, then the cable should be made with the higher ohms resistor like 4.7kOhms? When I use the higher impedance resistor, any sound quality will be less? Your advice is highly appreciated. Thank you.
The resistors are the same regardless of the source used. The resistor types I used are metal film.
@@electronicsoldandnew Ok Thank you.
Thanks for the video! I'll try to make the same adapter but with a RCA connector instead of the banana connectors since I've got two old tube radios that the previous owner installed a RCA connectors as line-in on them.
By the way can I know what's the brand/model or simply what's the name of this kind of stripping tool that you use? It looks really effective!
Well, I've should have done a little Google search first! They're called "Automatic Wire Stripper", but now I need to find where to buy one!
I think you’ll probably find them any any electrical store or pound store
Thanks! But I'm still curious to know the brand/model of yours, if you remember it, since it seems to work well with small gauge wire. It seems to be a problem with cheaper ones.
It has no brand, and ... it one of the cheaper ones. I think I paid about €3 for it
Hi Caldeira, First of all, thank you for the video. I'm an idiot when it comes to electronics, but I'm wondering how You would do it when you have 2 output signals (like R+ & R- and also L+ & L-)? I have a bluetooth device with 2 stereo outputs and would like to couple it with a comparable radio.
Twan : usually, the R- and L- are common and we call this the ground. You need to check if they are in fact a common ground. If so, then the rest is as explained in the video. Good luck.
M Caldeira thank you for responding. How can I check if they are a common ground? And what if this is not the case? Lastly, another question, do I need shielded cables?
Twan : Measure with multimeter. You will find that two of the output connectors will measure as a short, meaning it’s connected to the same point, meaning ground.
What happens if you short the right channel (ring) to ground?
You’ll possibly stress the source’s output and can do damage.
Great video. I made one and works terrifically with my Heathkit ea 2 mono amp. What resistor would you use for a normal turntable, (no preamp). Thanks!
Probably a little higher, but you need to try out a few values and see which works best with the particular turntable.
@@electronicsoldandnew Thanks for the response. I thought it would be smaller since the phono signal is weaker. I'm a novice of course. Cheers from Iowa.
@@brianbeers3123 The Pickups provide a voltage output with very low current capabilities. If you use very low resistors, the pickup will have problems supplying the load and drop signal.
@@electronicsoldandnew That makes sense. You've inspired me. I've got an old GE tube radio that does not work. I think I'll dig into it next. Thanks again!
Hi I'm a little unsure as to the need to do this as your ipod iPhone and even my cheap Samsung galaxy (bottom of the range)already has a mono output option in the accessibility section of settings?
Am I missing something?
Cheers dave
Incidentally the mono option also works via Bluetooth so should work without moding the cable with resistors ...shouldn't it?
I agree that using the mono function would do away with the need for this adaptation, but it is much easier to simply connect any music source to a tube radio without having to adjust your phone or other music source. In fact, you don't even need to know that it is mono. You can simply connect it.
@@electronicsoldandnew thanks for reply, at least I now know I'm not doing anything wrong overall, I've started repairing old bush srp31 record players and adding Bluetooth modules to sell on the bay with a mono shorting jack input and didn't want to ruin someone else's equipment in the process, I let them know they need to switch to mono on device. Hopefully nobody plugs a device which isn't mono switchable in!😱
Stay safe
I have a Fisher mono receiver with only a RCA input and not separate ground connection. What would I do with the ground connection from the stereo 3.5 connector? is the outer connector on the rca the ground?
LeBauer Physical Therapy, LLC : yes, the outer is the ground.
@@electronicsoldandnew awesome thanks! just got it all soldered up (not as neat as you) and it sounds great! :-D
Wow, I think you can help me! (Sorry for my bad english btw) I have an old reel recorder, an el 3536 Philips. The speakers are in the lit. I like to play guitar on this thing. The extra speaker output, rightside from the input you are showing on your old radio looks similar as mine, three holes. Does it Works the same the other way around? Can I use 2 bananaplugs (or 3, because 3 holes) and connect these together to a female 1/4 plug? So I can connect a guitar speaker box to it? Thanks for help! Greetings
I don’t think so. The two sockets are for an external speaker by itself, of in parallel with the internal one. Each radio will be different, so following this example will not necessarily work with another radio.
@@electronicsoldandnew , thanks for helping me out...but it could maybe work? I am totally not technical...so. If I want to connect a guitar speaker with a 1/4 plug, I have to open the old tape recorder and change something inside? (By a pro 😉)
Broek Hoest : I suggest you get someone to look at it and advise you, or you could do some serious damage.
@@electronicsoldandnew thanks for the advice!
I went onto Amazon to order 1k resistors and saw that there are 1/4 watt, 1/2 watt, and 1 watt options. Which should I choose?
In this application the ¼ W are fine.
Thanks... super quick response too! 🏎💨
would a diode work on each channel to stop it from traveling back into the amplifier?
No, a diode would rectify the signal. Not good.
M Caldeira thank you rectifying my question!!! Nice video, thx for the quick responce! !!
Can this process be used to convert a microphone with a 3.5 mm stereo tip to mono 3.5mm or 1/4 inch tip? Or what would be the best way to do that? (I need to use a stereo mic in a mono port.)
rdoss1. Yes
But NOT simply combining left and right together like you mentioned early in the video?
No, don’t do that. The two elements just end up “fighting” each other instead of adding together as they should.
I want to take 2 quarter inch Jack signal ( Left and Right ) line level from a mixing desk to 1 mono sum Jack or male xlr into a powered stage monitor will the system on this video this work, cheers Mick
It should work fine. You’re effectively just adding two line level signals.
Electronics Old and New by M Caldeira Do I still need to put 2 1k resistors as you did in the video. I’ve just bought a new small mixing desk and want to take a mono sum from the overall mix into a powered stage monitor, I was thinking of using maybe the phones output on the desk or the control room stereo outs thanks again Mick
Micky Malibu : yes, use the two resistors.
I am kind of having a Question with the opposite Problem.. How to get, via Cable, Sound out of an old Radio with 5 Pin DIN Socket?
I have a Radio with a 5 Pin DIN Socket and I want to record from this Radio. So I want to use the Tape Out of this Radio. But when I connect Pin 1 directly to a normal RCA Input, the Signal was very weak. I heard, that the Output Signal of a DIN Connector on a Radio with DIN Socket can be low and tends to be (more or less) high Z. Because of this I connected the Signal from Pin 1 at the DIN Socket to the Input of a DI-Box and the Output of the DI-Box to the Mic Input on a Mic Preamp. That seems to work. Would that be a possible Solution or is there a better Way to do it? The Radio is mono.
If you’re sure that pin 1 is in fact the tape output, then that would be the way to do it. I’m not sure that all the radios I’ve done follows that rule. You could also use the speaker output through some attenuation into the DI. That may produce good results too.
@@electronicsoldandnew - Thank You for Your fast Answer! I will try that too! At least for my Radio the Tape Out is Pin 1. I tested that. Maybe it is standarized this Way. Because that is what DIN stands for. It is the German Organiation for Standarization.. But it could be possible, it is only this Way for Radios. For Tape Recorders with DIN Socket it could be wired "differently". Because the Tape Output has to go to an Input and normal DIN Cables do not seem to be "crossed".
@@electronicsoldandnew - I "experimented" now a bit with the DIN Tape Recorder Output at the Radio and found, that I had to add a Resistor after the DIN Output to Ground to "simulate" the typical Input Impedance of an old German Tape Recorder. And now it works and the Sound is more or less stable and has a "wide" Bandwide and it sounds (more or less) the Same, regardless if I use the Mic Preamp or the DI-Box (the two Device have _very_ different Input Impedances.. ). Before I did that, the Sound changed _a lot_ with the different Input Impedances of the different Devices.
The Speaker Out worked also, but not as good as the DIN Tape Recorder Output at the Radio. (In my Opinion). The Sound at the DIN Tape Record Out is "wider" maybe and it is also not affected by the Tone Control of the Radio.
DE2017 : glad you got it working. The DIN output is in fact before the tone controls and you also don’t get the power stage effects like distortion.
Hello Sir ! please help ! I see current flow on the pickup input, i tested it with tester (dont have a multi-meter)! should i connect my phone to it, with the cable which i made with the help of this video ?
ManuLeisure : what do you mean? Your pickup input should not have any voltage at it, so I don’t understand how and what you are measuring if you don’t have a multimeter.
@@electronicsoldandnew i mean is it normal to have any voltage on pickup input ? i checked with a simple pen tester there is voltage, i dont know how much it is, so what to do ?
ManuLeisure : you can’t connect up your music source until you have tested the input properly. You need a multimeter to do that.
@@electronicsoldandnew i will get one soon. Thank you!
Hi, thanks for the info! I would like to use my Guitar Amp as a speaker and my smartphone as source. Is it possible? Should I make a custom cable or there is something in the marketplace to buy?
Fender FM 210R - 65 W output
Luxor TheFirst : not really a good idea because the input level of a guitar amp is supposed to be quite low compared to the output from your smartphone. The cable would basically be the same, except that it would go into a mono jack to connect to your amp. The result would probably have quite a bit of distortion due to the signal level, and the inherent distortion that your guitar amp would introduce, but it will work.
Electronics Old and New by M Caldeira:
Thank you for you hint. I just managed the thing this way:
1) setting Windows (or iPhone as well) to Mono sound (see “Ease of access” options)
2) using a cable with a standard jack 3.5 (stereo) and at the other end a standard guitar jack (mono)
3) plugging in the guitar jack in the amp, specifically into its secondary input (the one “less sensitive” studied for guitar with higher output)
4) lowering Windows master sound to 1%
5) adjusting/balancing sound between both Windows and Amplifier
6) setting/testing Equalizer through Windows audio settings - Speaker Properties - Enhancements
Get an iRig from IK multimedia website, not a cheap option but works well with smartphone
Hi, I have a Question, can I use 2 Diodes o a transitor instead of resistors?
Nope.
I would like to know why, Its been a while since I'm looking for a solution to connect a stereo R L output to my single Mono MIC input.
I think the video explains it all. You are summing the left and right signals.
It should not, because diode wont let the signal go back. Diode has only one direction.
So then in series 1 K on each lead from iPhone should be ok then?
Raul Montesdeoca : yes it should.
Electronics Old and New by M Caldeira Thank You.
hello sir ! i have a Phillips b6ca 97a tube radio with pickup input ! i dont know weather this model is 'hot-chassis' one! i want to play music from my phone please help!
ManuLeisure : it’s not a hot chassis radio. The service manual is at:
nvhrbiblio.nl/schema/Philips_B6CA86A.pdf
@@electronicsoldandnew it means i can plug music as you described in this video ! sorry i am no expert!
ManuLeisure : yes.
@@electronicsoldandnew Thank you sir ! highly appreciated !
Would this work for a Bluetooth adapter?
jenine yost : if you mean to connect a stereo by receiver to the radio, then yes.