Wood, it's my thought that the old time radios and train transformers (40-50's era) didn't include a ground. The issue comes if wires come loose inside the cabinet and touch the cabinet, electricity CAN/WILL flow through your guitar cable (through the ground) and can shock the crap out of you. Just buy an AC cord with 3 wires and connect the ground to the chassis and the black and white wires to their respective places inside the cabinet.
Why use a ground? You know how many products don’t use a ground today ? I always keep everything factory you add a ground you are asking for bugs or hums or buzzing
I do think there is not a single old radio with a grounded wall plug. The essesional question is wether there is a transformer in it. Only then you can do this savely. The very old radio's do not use a transformer but are direct in galvanic contact with the house power net! that can be deadly.
Cool, I did the same with a similar radio and removing the destroyed oval speaker and replacing it with and old TV speaker. Not loud but a beautiful tone. As you say its not hard , just by using common sense you can use the "phono" in as an instrument in. Your set up sounds better than many 50's combos do...well done! The main thing is "Dont touch any other object while you have the guitar in your hands, just play" I was playing through a radio and like a madman decided to reach out and turn a TV on....thats when I learned a big lesson. A giant hand came down and threw me against my bedroom wall. I was 14 at the time and that shock made me go to college and learn how to do it right.
See, YOU did more than just learn from that mistake, you got back up, brushed yourself off and said, "Is THAT how it is? Okay, I'm going to conquer you, electricity!" I had the same thing happen to me when I was 5. Earliest memory that I have. Dad was working on a 30's Floorstanding tube radio on the front porch when I came out, saw a light bulb and just HAD to touch it. I got an abject lesson in the power of current that day and it has stuck with me ever since.
@giulioluzzardi7632 haha, always. Though it still shows me who's boss every now and then. Last project (and still trying to fix it) was a B-52 AT-100. I should listen to everyone on the message boards and gear forums and just save my money to invest in something reliable, but I Love the sound of my AT-112 and to have what amounts to a Mesa Triple Rectifier for 1/10th the price is just too appealing. One of the power tubes clearly burned part of the board at one point, but after replacing all the bad resistors, fuses, and recapping, it still doesn't turn on. Probably one of the 4 transformers, but that's still a little advanced for me.
The phrase "I just want this to be easy" is a little frightening when you're talking about DIY with vintage tube gear. Try measuring the voltage difference between your guitar strings and a grounded source (sink, etc) when it's plugged in and turned on. That's a great quick and dirty way to avoid potential shocks.
I used to use an d Phillips reel to reel tape recorder with the PA button engaged to drive my little zenta amp. Sounded like Brian may. This was in 1973. Decades before I heard about Deacey, his little amp.
When I was high school I got my first electric guitar but didn't have an amp or money for one but what I did have was an old Learjet stereo with 1/4" input on the back. Worked just fine. :) nice to see some one doing something like that. Brings back good memories.
35 years ago, I used to plug my dad's 1966 Teisco Del Ray into his Teac reel-to-reel as a preamp and then use the power from his Sansui receiver to get serious fuzz and sustain for days through the Sansui 4-ways. Damn it was loud! Our neighbors would get so pissed, lol. I remember that the receiver had like a dozen tubes in it because I fried them all one day and he about killed me when they told him what was wrong with it. He still has it all packed away. I may have to see what a good guitar (my Strat) sounds like through all that...with some stereo chorus.
I like to see those old radios restored to their origional form. Now I’ve seen where an aux jack has been added to connect a guitar but the radio is disconnected when a guitar is plugged in and the radio comes back on when guitar is disconnected.
Hahaha, I'm sitting on the shitter watching CZcams videos like I'm sure everyone does.. I'm watching your video and just ask you plugged in the 1/4" jack into your guitar someone dropped something upstairs which made a huge banging noise and scared the shit outta me... literally! Good thing I'm sitting where I am! 😂👍🏽 Cheers from a fellow Canadian 🇨🇦
When I was a kid (about 10) I saved up and bought a second hand Kay 'strat' copy(with Dimarzio pick ups :-) ) but I had no way of affording an amp. I got a really old valve radiogram. It had no inputs so I wired it in by twisting the bared jack cable wires with bared ones from the record arm and I taped them.. It worked great. I built one from a Revox reel to reel tape player later at school . I bet loads of people have tried similar things. There was a time when you bought a guitar and you DIDN'T get a little free amp and digital tuner. You had pitch pipes haha.
Yes, I remember when I first started playing in the early 60s. People were throwing pre war radios out to get later models. They had large speakers and a pick up socket in the chassis (To run a record deck). Eventually, the speaker used to fail and sounded distorted (although it was an exciting sound!) We would then just get another radio.
I could never afford a proper amp for years. I enjoyed making amps out of pre-existing things. It's funny as now you can't move in pawn shops for them. I think doing things like that were fun.
You are on the right track. All you need to signal both channels is a RCA Y to 1/4 in. mono plug. The hum could be just from the P90 pup or the filter cap in the power supply is dry(needs to be replaced). I know you are trying to do this on your own, but it will take a person who knows what they are doing to make even the simplest repairs on this project. Man you were right, it does kick booty! Thankz
If you’re not going to use it as a HiFi or radio I’d just install a grounded power cord. What you’ve done isn’t inherently unsafe, if you’re careful and it doesn’t use series string heater tubes. I’d avoid pigtail input wires eventually. I’d eventually isolate the circuit you’re using by disconnecting the unused functions at the switch or pulling the unused tubes. Make sure you don’t have leaking caps at the tubes in your used circuit. It sounded surprisingly good. I’m 70 now and I modded my first amp in high school using an old Grundig tape recorder.
Here is the reason why you're at very high risk of getting electrocuted using that old tube radio as a guitar amp. The thing stopping you from getting electrocuted are some over 50 year old capacitors which have been nicknamed death caps. Once they go bad (they will soon if they have not already) you will have a hot chassis. When you plug your guitar into the radio your guitar is grounded to it which also when you plug your guitar into the radio your guitar is grounded to it which also makes your guitar hot. When you touch your guitar strings you become grounded to it also. At this point all you have to do is touch something grounded like a microphone and the electricity will exit your body leaving burn marks and possibly stopping your heart. There are two ways to prevent this from happening if you want to use it as a guitar amp. 1. Replace the capacitors 2. Ditch the capacitors and install a grounded cord to it. Also it's always good to check the chassi with a multimeter to see if it is hot
OK - I work with alot of tube radios. It will not kill you if you are a smart person. Yes tubes have lethal voltages but they are in DC and the audio path of 99.9999999% of the time has capacitors of .2 or .5 or .02 or .05 mfd as the blocking component to ONLY ALLOW the audio signal AC to pass. Yes, basic safety upgrades are wonderful if you can do them but remember this. It was designed that way! 'and when it was made (pre 1965) we didn't have a plague of radios killing people. So yes, today we don't consider it up to par with safety standards but it it's day... it was. I would recommend pulling the schematic for ANY old radio or amp and identify if it has a "HOT CHASSIS" (or you can also just turn the radio off, leave it plugged in, and with a voltmeter 1 probe on metal radio chassis and 1probe on ground. If while off, it shows line 120 volt AC voltage but then drops to ZERO once turned on... that is a HOT CHASSIS!!! 'And you can still use it as an amp BUT, VARY IMPORTANT (DO NOT EVER just turn the radio off while your guitar or device is plugged in. Either unplug the guitar from the radio THEN turn off the radio OR better yet, just unplug the radio TO turn it off. 'Or, use a power strip with a switch.) IF your radio doesn't have a hot chassis design..... then no need to worry about any of that. THAT IS THE MAIN CONCERN WITH OLD TUBE STUFF: if while OFF it charges the ground/chassis because of its design. 'And yes it was designed to do that so it is operating as it should despite the dangers to human health. LOL NEXT - in your schematic see if the phono/input channel has a capacitor before the grid of the first tube. It should, 89% of the time they always do, BUT if it doesn't... No big deal... When you make your guitar cable to adapt to the radio just solder in a capacitor and shrink wrap over it so it's part of the cable. All done!!! Now if you end up with an old tube with a leaky grid.... The DC voltage won't back feed to the guitar. As far as what value capacitor to use? Depends on the sound you prefer. I recommend a .02 or .05 mfd 630v to keep the sound being as true as possible. So know your equipment, be wise and you will always be safe. Old tube devices are awesome! love them personally! I love the way they sound! Even an old radio makes a fabulous amp for a guitar or an MP3 player. No one has to know exactly how everything works, but you just have to know enough to make sure you can operate it safely 'for you.'
I've got a Emud Rekord 60 senior I'm trying to see how it will sound as a guitar amp. It has a phono input jack so I think I could slice a guitar cable onto a plug that will fit it hopefully it will work.
That’s a really good radio, it’s got a power transformer this isn’t an ac dc set! So you in pretty good shape, I’d personally recap it! Your at least check too see if it’s been! Some of the caps you may want to keep for a specific tone though!
its unsafe because the radio can be either live or neutral depending on what way you plug the radio in (plug can be plugged either way). yes. if you touch the strings that's not going to fry you. you touch the pickups or a knob that is routed through live and that will show you a good time. the outside of the audio jack can be the live end too. (i see its an older video, but i thought it might be nice for those unaware and thinking of doing this). dont fucking do this unless you know what you are doing.
Which are the positive and negative and pins you would reccomend to use? Seems like most people connect them to the volume potentiometer and since i have tò do It im trying to understand how ti do It without problems
Some of us are risk averse and some are risk takers. Trying to convince someone whose outlook on life is diametrically opposed to your own is a waste of time. Those of us that took stupid risks as kids and didn't die in the process have grown up feel the risk is worthwhile and possibly learnt enough to survive most stupid acts. For example the back of the hand test... Bravo for keeping the spirit of adventure alive. Two thumbs up ;-)
What types of tubes does tat old radio use? 12ax7 preamp, el84 PA? anyway, you could rebuild the face of that radio to make it look very nice, essentially turn it into a small wattage guitar head. make it match a nice 2x12 cab and you have your very own brand of amp :P I've seen your videos and know you are handy with a saw, there's alot of potential in that one.
That's not just you're P90, it sounds like you have a ground fault somewhere. As far as getting shocked there is high voltage anytime you're dealing with tubes and transformers. However, I don't personally see a lot of risk in what you've done. Speaking of being shocked though a LOT of the older amp equipment that I've dealt with has dealt some pretty wicked shocks. I had a 50's tweed Fender Tremolux years ago in my youth that my bandmates and I dubbed the shocker due to the fact it shocked people on a fairly regular basis. Kept practices quite interesting. Boy do I wish I had that amp today though...
nothing wrong with that set-up , it does sound CRAZY GOOD ! you've stumbled on a magic combo there ! whats the speaker ? when we used to plug into ANY amp back when , always just lightly touch the strings to see if theres a shock . try just reversing the 2 prong plug to reduce hum . DO NOT change to 3 prong w/out adding polarity switch and caps . was sceptical when this came up but really enjoyed seeing AND HEARING THAT GREAT SOUND ! 50+ years ZAPtronics & music experience , wanto talk further , whats you contact info you know you don't need to keep your mouth sounding like a sewer .
Does the amp list how many watts it is? And are those old amps typically for 8 ohm speakers? Thinking about doing one of these. Tusskmusic or Woodeso, I'd like to find out what Tusskmusic had to say off the record as he mentioned. Please PM me with that if you can. Thanks.
Gotta give you a hand for the honesty. Humorous honesty gets you bonus 👏 👏 👏. "I don't really want to know how all this shit works." I wish I had that sense of brevity. I just finished my second electrical engineering textbook in an attempt to understand how to build effects pedals. Now, could I have just bought a kit from Stewmac complete with all parts, instructions, schematics, and built it? Sure. Except my damn brain then has to say "Cool pedal bro, but how does it work?" Gets me every time. Worst part of that caveat: I'm also incredibly fickle in my choice of hobbies and a terrible long term memory, so I would venture a guess that I have learned and eventually forgotten Fundamentals of: Blacksmithing, Knifemaking, Horology, Luthiers, Neumismatism, Machining, and Automotive Technology. This will be just one more stack of knowledge to leave me in 6 months after I watch a CZcams video on Ornamental Horticulture or some damn thing. Although I did come across this video because I have a 40's tube radio, and was interested to find out if I can turn it into a guitar amp, so maybe I can apply some of this electrical knowledge to that pursuit.
Unsafe coz of the mess, LOL! Thx for sharing, it sounds awesome. Like you, I leave the techie stuff to brainy ppl - I just want to get on with playing n recording music!
Once you go onto phono mode or accessory mode you cut out the radio stuff and are just using the front end of the amp to make the guitar live. It will not bite you if you put a 3 wire plug and cord and ground the steel chassis. You have lots of screw holes on the back. the rest sounds good. The hum will take sum work so forget it.
Brian Snyder That was my thought. I thought I'd just cut the end of the existing cord off it, grab a 3 pronger, ground it to the chassis and start there. I also had an idea of getting an AB/Y pedal and using it to send signal to both channels on the amp, since it's in stereo. I had 2 - 12's hooked up to it about an hour ago... and holy crap it's loud. But I worked out, it's only sending signal to one side... DOH! So I'd like to make use of both sides so I don't over extend just one end of the amp. Kinda where I'm at with it at the moment:-) Thanks for the advice! And yes, I know there's an internal ground issue somewhere to deal with;-)
Woodeso's Guitar Mods You are probably getting the hum because the phono cartridges are very low impedance more or less around 30 ohms to 150 ohms. If you have much higher impedance like a guitars, you will get hum. There are input resistors that can be modified in the phono input stage to improve the match, but that is where you need a schematic and know what you are doing.
OK so the one thing you must do is have a speaker hooked to both channels! If you don't, at some point you run the risk of failure of the whole amp! It could even shock you or catch on fire. I guess in your case yo could or not put a handle on it and use it as is. The radio was meant to be plugged in and used with no cord coming out of it to a person. Converting it to a 3 pronged plug is a good idea. Surely you know someone that has what it takes to do that. Thanks
In the day it was almost common knowledge, what you want to do with out any real understanding. In some ways taking a radio like this (valve) is easier than taking a transistor equivalent to do the same thing. Being Schooled in the way of the transistor when I did my trade Transistors are easier for me, But I am taking my time to work out how valve (tube) amplifiers work. The cool thing about that amp is you could run a stereo effects!
The reason they are unsafe is the same reason that tube amps of the same vintage are unsafe. You have two wires going into the back of the radio/amp. One is 'hot' and one is 'neutral'. The hot one has 110~125v @ up to 15 amps on it, the other one is a return line for the a/c signal to complete the circuit. Modern plugs are polarized, that is the hot ALWAYS goes to the wire intended to be 'hot' and the neutral ALWAYS goes to neutral. With a non-polarized plug (both pins being the same) you can accidentally connect them backwards making the steel chassis (the part of the radio/amp that everything is mounted on) 'hot' this includes the negative wire on the signal connection to the guitar. Here's where it gets scary. IF you are on a carpet in a basement and it's damp that 110~125v @ up to 15 amps we talked about earlier can go right through your arm, down your leg, and into the wet/damp concrete and ground. This renders you dead. Do not pass go, do not pass $200. You are DEAD. Plain and simple. This doesn't matter if it's transformerless or not, they all did it this way. The BEST thing to do it to get a schematic for the amp/radio and find out which line is supposed to be 'hot' and which is neutral and put a polarized line cord on it, some will say use a grounded cord, but that requires a LOT more work. With a polarized cord you can prevent it being plugged in the wrong way.
Walter Weimer connect an input jack to the volume pod,its easy i convert radios and transistors for my cigarboxguitars for 20 years now and never had a problem
One thing to do to make the whole thing much less dangerous. Fit a mains lead with an earth connection, fix that to the chassis. If the amp fails you won't find the mains voltage going through your strings, the fuse will blow. Dead simple.
The non grounded old school non polarized tube radios, phonographs, amps, etc. Can when something fails send current through the chassis, output, etc. Keep in mind these things convert 115 volt AC into up to over 400 volt DC. This is the danger, DC can kill you or seriously injure you faster and easier than AC. The tubes need different voltages rectified to them to work as intended. Some of the circuits are low voltage (around 5 or 6 volts) others can be in the 250 to over 400 volts range. And, again this will be DC volts.... far more a risk than AC.
The phono input is what you needed. If you had to go in and do surgery you would have need to drain all the capacitors first, then read the schematics to find your way to the preamp circuit, but that's what the phono input is. Have fun!
I have a 1960 Carvin #28-212-B. It's a guitar amp, and I'm terrified to turn it on. It's got burnt out tubes, missing 3 speakers, and the worst part, the output transformer is powering 1x12 Jensen P12r. The wires for the other speakers out of the transformer has been cut. it's a $2g amp that I refuse to turn on longer than 1 minute.
+theassassin757 because I don't have any of the equipment needed for repair besides a soldering pen/gun. Also after reading forums, I don't want to die at 23 lol. It would cost more than a grand to have the guy I use to maintain my gigging/touring amps to fix after finding the matching/original parts.
Sir, you are exploring the original Blues :D in the beginning there were no home amplifiers or PA setups, no mixing desks and life was dangerous ;-) I am an old radio ham so my gut feeling is that if this radio has had phono connectors retrofitted for say a record player to use it as an amplifier then it should be diode protected and hopefully you are safe. However in my experience old gear has a habit of biting back as you have no idea what previous owners have done to it. A simple test is to check if you are getting an A/C ripple through the phono sockets. Old transformers break down like old guitar pickups do so be careful my friend :-)
that piece of gear by itself is probably not going to be dangerous to you. The problem occurs because on vintage tube gear the grounding scheme was not particularly well thought out with respect to the AC mains "hot" and "neutral". If you have seen the comedy routine where someone touches a microphone while playing guitar and gets zapped then you have the correct picture in your mind. Plugging into your radio/amp can put your body at an electrical potential above ground. How far above ground depends on a number of factors. If you create a path to ground through your body by touching another piece of gear or something else metallic, then you will most likely experience a shock. The severity of the shock could be small, as in most cases, but the potential is there to create a life threatening condition. The fix is a "three prong" AC mains cord set. Its a pretty common modification to vintage gear. Its cheap and easy to do.
well you need to know what youre doing if youre making a tube amp for guitars , there are still voltage in the amp even if you pull the cord , thats why there is no movie just do it like this out there , but if you want to make a amp read books about the subject , look at schematics how things work ,
PLEASE watch 13 minutes of Uncle Doug here. czcams.com/video/xS_5K5YEYv8/video.html Then switch the power cord with a 3 prong grounded one! Then cut out the death cap if it has one.
Your American mains is not anywhere like our 230 volts in GB. Less likely to be lethal, but still needs to be treated with respect. The best thing isto keep one hand in your pocket as an old tech told me. The theory is if you take the full force of a charged B+ filter capacitor or worst case the raw mains the charge will not cross your heart. Then the worst that happens is you drop a few F bombs & your daughter still has a daddy. To turn the radio into a substitute guitar amplifier the radio should have a 'cold' chassis. That means the filament supplies and the source of the B+ should come from a transformer. There should be no electrical connection between the mains plug & the chassis apart from a ground pin in a 3-pin plug. You need the circuit diagram for the radio to get this information. If you are not skilled in valve amp work and high-voltage work I would not advise attempting the project.
I used to play my guitar through an old tube radio back in the 70s. I did the same thing you are doing here, plugged it in through the record player jacks. It also sounded bad ass. I have no idea why it is supposed to be dangerous. I never got shocked.
Dont worry about electrocution,and if you dont have a phono input just solder a input jack to the volume pod,i been doing radio and transistor conversions for my cigarboxguitars for 20 years now and never had a problem
you might not want to let your daughter touch the guitar and an earth ground. Even if it is turned off when plugged in you may have the same odds to letting her play with an electrical outlet.
Wood, it's my thought that the old time radios and train transformers (40-50's era) didn't include a ground. The issue comes if wires come loose inside the cabinet and touch the cabinet, electricity CAN/WILL flow through your guitar cable (through the ground) and can shock the crap out of you. Just buy an AC cord with 3 wires and connect the ground to the chassis and the black and white wires to their respective places inside the cabinet.
Why use a ground? You know how many products don’t use a ground today ? I always keep everything factory you add a ground you are asking for bugs or hums or buzzing
Good to know, thanks!
any old amp with a non grounded plug is a widow maker!!!
I do think there is not a single old radio with a grounded wall plug. The essesional question is wether there is a transformer in it. Only then you can do this savely. The very old radio's do not use a transformer but are direct in galvanic contact with the house power net! that can be deadly.
Cool, I did the same with a similar radio and removing the destroyed oval speaker and replacing it with and old TV speaker. Not loud but a beautiful tone. As you say its not hard , just by using common sense you can use the "phono" in as an instrument in. Your set up sounds better than many 50's combos do...well done! The main thing is "Dont touch any other object while you have the guitar in your hands, just play" I was playing through a radio and like a madman decided to reach out and turn a TV on....thats when I learned a big lesson. A giant hand came down and threw me against my bedroom wall. I was 14 at the time and that shock made me go to college and learn how to do it right.
See, YOU did more than just learn from that mistake, you got back up, brushed yourself off and said, "Is THAT how it is? Okay, I'm going to conquer you, electricity!" I had the same thing happen to me when I was 5. Earliest memory that I have. Dad was working on a 30's Floorstanding tube radio on the front porch when I came out, saw a light bulb and just HAD to touch it. I got an abject lesson in the power of current that day and it has stuck with me ever since.
@@Ten80pete Hi, still experimenting with "Lecky"?
@giulioluzzardi7632 haha, always. Though it still shows me who's boss every now and then. Last project (and still trying to fix it) was a B-52 AT-100. I should listen to everyone on the message boards and gear forums and just save my money to invest in something reliable, but I Love the sound of my AT-112 and to have what amounts to a Mesa Triple Rectifier for 1/10th the price is just too appealing. One of the power tubes clearly burned part of the board at one point, but after replacing all the bad resistors, fuses, and recapping, it still doesn't turn on. Probably one of the 4 transformers, but that's still a little advanced for me.
The phrase "I just want this to be easy" is a little frightening when you're talking about DIY with vintage tube gear. Try measuring the voltage difference between your guitar strings and a grounded source (sink, etc) when it's plugged in and turned on. That's a great quick and dirty way to avoid potential shocks.
I used to use an d Phillips reel to reel tape recorder with the PA button engaged to drive my little zenta amp. Sounded like Brian may. This was in 1973. Decades before I heard about Deacey, his little amp.
When I was high school I got my first electric guitar but didn't have an amp or money for one but what I did have was an old Learjet stereo with 1/4" input on the back. Worked just fine. :) nice to see some one doing something like that. Brings back good memories.
35 years ago, I used to plug my dad's 1966 Teisco Del Ray into his Teac reel-to-reel as a preamp and then use the power from his Sansui receiver to get serious fuzz and sustain for days through the Sansui 4-ways. Damn it was loud! Our neighbors would get so pissed, lol. I remember that the receiver had like a dozen tubes in it because I fried them all one day and he about killed me when they told him what was wrong with it. He still has it all packed away. I may have to see what a good guitar (my Strat) sounds like through all that...with some stereo chorus.
I recently bought a teisco del ray- I love it!
I like to see those old radios restored to their origional form. Now I’ve seen where an aux jack has been added to connect a guitar but the radio is disconnected when a guitar is plugged in and the radio comes back on when guitar is disconnected.
I love uncle dougs videos.... I'm so envious of his vintage amps.
I've been playing for over 50 years, and that's some mean sound, I love it.
Hahaha, I'm sitting on the shitter watching CZcams videos like I'm sure everyone does.. I'm watching your video and just ask you plugged in the 1/4" jack into your guitar someone dropped something upstairs which made a huge banging noise and scared the shit outta me... literally! Good thing I'm sitting where I am! 😂👍🏽 Cheers from a fellow Canadian 🇨🇦
🤣🤣🤣
When I was a kid (about 10) I saved up and bought a second hand Kay 'strat' copy(with Dimarzio pick ups :-) ) but I had no way of affording an amp. I got a really old valve radiogram. It had no inputs so I wired it in by twisting the bared jack cable wires with bared ones from the record arm and I taped them.. It worked great. I built one from a Revox reel to reel tape player later at school . I bet loads of people have tried similar things. There was a time when you bought a guitar and you DIDN'T get a little free amp and digital tuner. You had pitch pipes haha.
Yes, I remember when I first started playing in the early 60s. People were throwing pre war radios out to get later models. They had large speakers and a pick up socket in the chassis (To run a record deck). Eventually, the speaker used to fail and sounded distorted (although it was an exciting sound!) We would then just get another radio.
I could never afford a proper amp for years. I enjoyed making amps out of pre-existing things. It's funny as now you can't move in pawn shops for them. I think doing things like that were fun.
Dude that sounded great. I know this is an old video but I had to comment. Really sounded great! ✌🏻🔥
You are on the right track. All you need to signal both channels is a RCA Y to 1/4 in. mono plug. The hum could be just from the P90 pup or the filter cap in the power supply is dry(needs to be replaced). I know you are trying to do this on your own, but it will take a person who knows what they are doing to make even the simplest repairs on this project. Man you were right, it does kick booty! Thankz
sounds awesome! and its a brilliant Idea
If you’re not going to use it as a HiFi or radio I’d just install a grounded power cord. What you’ve done isn’t inherently unsafe, if you’re careful and it doesn’t use series string heater tubes. I’d avoid pigtail input wires eventually. I’d eventually isolate the circuit you’re using by disconnecting the unused functions at the switch or pulling the unused tubes. Make sure you don’t have leaking caps at the tubes in your used circuit. It sounded surprisingly good. I’m 70 now and I modded my first amp in high school using an old Grundig tape recorder.
1961 voice of music,reel to reel recorder w a tweed grill on the front ,its the best amp I've EVER heard,yes,its my secret weapon, lol..
Hey man thanks for the video, used to follow you on an older account but you got lost in the transfer, glad to be back !
hahahaha your child convinced me to subscribe. great stuff man. greetings from MEXICO!!!
Here is the reason why you're at very high risk of getting electrocuted using that old tube radio as a guitar amp.
The thing stopping you from getting electrocuted are some over 50 year old capacitors which have been nicknamed death caps. Once they go bad (they will soon if they have not already) you will have a hot chassis.
When you plug your guitar into the radio your guitar is grounded to it which also when you plug your guitar into the radio your guitar is grounded to it which also makes your guitar hot. When you touch your guitar strings you become grounded to it also. At this point all you have to do is touch something grounded like a microphone and the electricity will exit your body leaving burn marks and possibly stopping your heart.
There are two ways to prevent this from happening if you want to use it as a guitar amp.
1. Replace the capacitors
2. Ditch the capacitors and install a grounded cord to it.
Also it's always good to check the chassi with a multimeter to see if it is hot
OK - I work with alot of tube radios. It will not kill you if you are a smart person. Yes tubes have lethal voltages but they are in DC and the audio path of 99.9999999% of the time has capacitors of .2 or .5 or .02 or .05 mfd as the blocking component to ONLY ALLOW the audio signal AC to pass.
Yes, basic safety upgrades are wonderful if you can do them but remember this. It was designed that way! 'and when it was made (pre 1965) we didn't have a plague of radios killing people. So yes, today we don't consider it up to par with safety standards but it it's day... it was.
I would recommend pulling the schematic for ANY old radio or amp and identify if it has a "HOT CHASSIS" (or you can also just turn the radio off, leave it plugged in, and with a voltmeter 1 probe on metal radio chassis and 1probe on ground. If while off, it shows line 120 volt AC voltage but then drops to ZERO once turned on... that is a HOT CHASSIS!!! 'And you can still use it as an amp BUT, VARY IMPORTANT (DO NOT EVER just turn the radio off while your guitar or device is plugged in. Either unplug the guitar from the radio THEN turn off the radio OR better yet, just unplug the radio TO turn it off. 'Or, use a power strip with a switch.) IF your radio doesn't have a hot chassis design..... then no need to worry about any of that. THAT IS THE MAIN CONCERN WITH OLD TUBE STUFF: if while OFF it charges the ground/chassis because of its design. 'And yes it was designed to do that so it is operating as it should despite the dangers to human health. LOL
NEXT - in your schematic see if the phono/input channel has a capacitor before the grid of the first tube. It should, 89% of the time they always do, BUT if it doesn't... No big deal... When you make your guitar cable to adapt to the radio just solder in a capacitor and shrink wrap over it so it's part of the cable. All done!!! Now if you end up with an old tube with a leaky grid.... The DC voltage won't back feed to the guitar. As far as what value capacitor to use? Depends on the sound you prefer. I recommend a .02 or .05 mfd 630v to keep the sound being as true as possible. So know your equipment, be wise and you will always be safe. Old tube devices are awesome! love them personally! I love the way they sound! Even an old radio makes a fabulous amp for a guitar or an MP3 player. No one has to know exactly how everything works, but you just have to know enough to make sure you can operate it safely 'for you.'
yet... oh man that's got sweet drive just the right amount of compression. daughter is hilarious. you are blessed :)
Are you using a standard phonograph plug that goes from one jack to two to be able to plug into the back of the radio speaker?
LOL, i love your honesty!!!!
good job man,... dont know why you would want to do it but congrats on it working.
Sounds damn good. I'm not much of a clean guy myself, but man do I wish I had that sound. Just beautiful.
I've got a Emud Rekord 60 senior I'm trying to see how it will sound as a guitar amp. It has a phono input jack so I think I could slice a guitar cable onto a plug that will fit it hopefully it will work.
That’s a really good radio, it’s got a power transformer this isn’t an ac dc set! So you in pretty good shape, I’d personally recap it! Your at least check too see if it’s been! Some of the caps you may want to keep for a specific tone though!
Couldn't you use a line/di box with ground life to match the impedance and stay safe as it contains a transformer?
Love that T.V. Yellow!!
its unsafe because the radio can be either live or neutral depending on what way you plug the radio in (plug can be plugged either way). yes. if you touch the strings that's not going to fry you. you touch the pickups or a knob that is routed through live and that will show you a good time. the outside of the audio jack can be the live end too. (i see its an older video, but i thought it might be nice for those unaware and thinking of doing this).
dont fucking do this unless you know what you are doing.
Again, this depends on the type of radio used, this comment only goes for the U-types of radio. See comment above
Could you ground an old tube radio?
You can actually still do this with radios that don't have an aux input (phone, etc) but it gets a bit more involved.
Which are the positive and negative and pins you would reccomend to use? Seems like most people connect them to the volume potentiometer and since i have tò do It im trying to understand how ti do It without problems
Some of us are risk averse and some are risk takers. Trying to convince someone whose outlook on life is diametrically opposed to your own is a waste of time. Those of us that took stupid risks as kids and didn't die in the process have grown up feel the risk is worthwhile and possibly learnt enough to survive most stupid acts. For example the back of the hand test...
Bravo for keeping the spirit of adventure alive. Two thumbs up ;-)
sounds way better than i thought. Would be lush backed off even cleaner?
What types of tubes does tat old radio use? 12ax7 preamp, el84 PA? anyway, you could rebuild the face of that radio to make it look very nice, essentially turn it into a small wattage guitar head. make it match a nice 2x12 cab and you have your very own brand of amp :P I've seen your videos and know you are handy with a saw, there's alot of potential in that one.
That's not just you're P90, it sounds like you have a ground fault somewhere. As far as getting shocked there is high voltage anytime you're dealing with tubes and transformers. However, I don't personally see a lot of risk in what you've done. Speaking of being shocked though a LOT of the older amp equipment that I've dealt with has dealt some pretty wicked shocks. I had a 50's tweed Fender Tremolux years ago in my youth that my bandmates and I dubbed the shocker due to the fact it shocked people on a fairly regular basis. Kept practices quite interesting. Boy do I wish I had that amp today though...
it is the p 90 the signal would be weaker if this was a ground issue
nice playing
nothing wrong with that set-up , it does sound CRAZY GOOD ! you've stumbled on a magic combo there ! whats the speaker ? when we used to plug into ANY amp back when , always just lightly touch the strings to see if theres a shock . try just reversing the 2 prong plug to reduce hum . DO NOT change to 3 prong w/out adding polarity switch and caps .
was sceptical when this came up but really enjoyed seeing AND HEARING THAT GREAT SOUND !
50+ years ZAPtronics & music experience , wanto talk further , whats you contact info you know you don't need to keep your mouth sounding like a sewer .
Does the amp list how many watts it is? And are those old amps typically for 8 ohm speakers? Thinking about doing one of these. Tusskmusic or Woodeso, I'd like to find out what Tusskmusic had to say off the record as he mentioned. Please PM me with that if you can. Thanks.
was that a bit of stevie's blues by tommy emmanuel at the 5:20 mark ??
***** yes indeed.. been trying to learn to play it properly for a year.. still shit at it;-) But I'm trying..
I thought you are fluff. You got his voice
That was seriously fucking cool.
Gotta give you a hand for the honesty. Humorous honesty gets you bonus 👏 👏 👏. "I don't really want to know how all this shit works." I wish I had that sense of brevity. I just finished my second electrical engineering textbook in an attempt to understand how to build effects pedals. Now, could I have just bought a kit from Stewmac complete with all parts, instructions, schematics, and built it? Sure. Except my damn brain then has to say "Cool pedal bro, but how does it work?" Gets me every time. Worst part of that caveat: I'm also incredibly fickle in my choice of hobbies and a terrible long term memory, so I would venture a guess that I have learned and eventually forgotten Fundamentals of: Blacksmithing, Knifemaking, Horology, Luthiers, Neumismatism, Machining, and Automotive Technology. This will be just one more stack of knowledge to leave me in 6 months after I watch a CZcams video on Ornamental Horticulture or some damn thing. Although I did come across this video because I have a 40's tube radio, and was interested to find out if I can turn it into a guitar amp, so maybe I can apply some of this electrical knowledge to that pursuit.
What make n model radio?
Unsafe coz of the mess, LOL!
Thx for sharing, it sounds awesome.
Like you, I leave the techie stuff to brainy ppl - I just want to get on with playing n recording music!
yes you may trip in the wires ,
I want a double cut junior so bad
im pretty sure it's a single cut
I dig it. My kinda mod.
I’m not sure if you noticed the guitar amp you were leaning you guitar on?
usually those types of radios have an auxiliary or phonological each jack and it might have a selector switch... in my limited experience
Once you go onto phono mode or accessory mode you cut out the radio stuff and are just using the front end of the amp to make the guitar live. It will not bite you if you put a 3 wire plug and cord and ground the steel chassis. You have lots of screw holes on the back. the rest sounds good. The hum will take sum work so forget it.
Brian Snyder That was my thought. I thought I'd just cut the end of the existing cord off it, grab a 3 pronger, ground it to the chassis and start there. I also had an idea of getting an AB/Y pedal and using it to send signal to both channels on the amp, since it's in stereo. I had 2 - 12's hooked up to it about an hour ago... and holy crap it's loud. But I worked out, it's only sending signal to one side... DOH! So I'd like to make use of both sides so I don't over extend just one end of the amp. Kinda where I'm at with it at the moment:-) Thanks for the advice! And yes, I know there's an internal ground issue somewhere to deal with;-)
Woodeso's Guitar Mods You are probably getting the hum because the phono cartridges are very low impedance more or less around 30 ohms to 150 ohms. If you have much higher impedance like a guitars, you will get hum. There are input resistors that can be modified in the phono input stage to improve the match, but that is where you need a schematic and know what you are doing.
Can you tell me more about modifying those input resistors in the phono stage which would make it more suitable for guitar use? Thanks for any help!
i love your batcave
OK so the one thing you must do is have a speaker hooked to both channels! If you don't, at some point you run the risk of failure of the whole amp! It could even shock you or catch on fire. I guess in your case yo could or not put a handle on it and use it as is. The radio was meant to be plugged in and used with no cord coming out of it to a person. Converting it to a 3 pronged plug is a good idea. Surely you know someone that has what it takes to do that. Thanks
In the day it was almost common knowledge, what you want to do with out any real understanding. In some ways taking a radio like this (valve) is easier than taking a transistor equivalent to do the same thing. Being Schooled in the way of the transistor when I did my trade Transistors are easier for me, But I am taking my time to work out how valve (tube) amplifiers work. The cool thing about that amp is you could run a stereo effects!
The reason they are unsafe is the same reason that tube amps of the same vintage are unsafe. You have two wires going into the back of the radio/amp. One is 'hot' and one is 'neutral'. The hot one has 110~125v @ up to 15 amps on it, the other one is a return line for the a/c signal to complete the circuit. Modern plugs are polarized, that is the hot ALWAYS goes to the wire intended to be 'hot' and the neutral ALWAYS goes to neutral. With a non-polarized plug (both pins being the same) you can accidentally connect them backwards making the steel chassis (the part of the radio/amp that everything is mounted on) 'hot' this includes the negative wire on the signal connection to the guitar. Here's where it gets scary. IF you are on a carpet in a basement and it's damp that 110~125v @ up to 15 amps we talked about earlier can go right through your arm, down your leg, and into the wet/damp concrete and ground. This renders you dead. Do not pass go, do not pass $200. You are DEAD. Plain and simple. This doesn't matter if it's transformerless or not, they all did it this way. The BEST thing to do it to get a schematic for the amp/radio and find out which line is supposed to be 'hot' and which is neutral and put a polarized line cord on it, some will say use a grounded cord, but that requires a LOT more work. With a polarized cord you can prevent it being plugged in the wrong way.
did this with a modern radio, no danger as long as your earthed, all goes down, you'll be fine man
Nice, but what if the radio has no phono out?
Walter Weimer connect an input jack to the volume pod,its easy i convert radios and transistors for my cigarboxguitars for 20 years now and never had a problem
thanks a lot !
One thing to do to make the whole thing much less dangerous. Fit a mains lead with an earth connection, fix that to the chassis. If the amp fails you won't find the mains voltage going through your strings, the fuse will blow. Dead simple.
Whats the song at 1:37?
That's cool. I want to try that now... It sounded so good.
If you are worried it's going to shock you poke the dials with a plastic handle and don't touch anything unless it's turned off
Dumb ass.
WOW!
super!+++
The non grounded old school non polarized tube radios, phonographs, amps, etc. Can when something fails send current through the chassis, output, etc. Keep in mind these things convert 115 volt AC into up to over 400 volt DC. This is the danger, DC can kill you or seriously injure you faster and easier than AC. The tubes need different voltages rectified to them to work as intended. Some of the circuits are low voltage (around 5 or 6 volts) others can be in the 250 to over 400 volts range. And, again this will be DC volts.... far more a risk than AC.
The phono input is what you needed. If you had to go in and do surgery you would have need to drain all the capacitors first, then read the schematics to find your way to the preamp circuit, but that's what the phono input is. Have fun!
I have a 1960 Carvin #28-212-B. It's a guitar amp, and I'm terrified to turn it on. It's got burnt out tubes, missing 3 speakers, and the worst part, the output transformer is powering 1x12 Jensen P12r. The wires for the other speakers out of the transformer has been cut. it's a $2g amp that I refuse to turn on longer than 1 minute.
$2,000?? If that's how much it's worth then why not fix it?
+theassassin757 because I don't have any of the equipment needed for repair besides a soldering pen/gun. Also after reading forums, I don't want to die at 23 lol.
It would cost more than a grand to have the guy I use to maintain my gigging/touring amps to fix after finding the matching/original parts.
+GabrielTheGuitarist oh I see. Well that's completely understandable lol.
+GabrielTheGuitarist I'll give you 50 bucks for it.
+SodomySnake haha..no doubt!
gentlemen.. today we learnt something invaluable.. when someone tells you something.. ask .. "WHY?"
sounds nice!
UD talks like a robot
Sir, you are exploring the original Blues :D in the beginning there were no home amplifiers or PA setups, no mixing desks and life was dangerous ;-) I am an old radio ham so my gut feeling is that if this radio has had phono connectors retrofitted for say a record player to use it as an amplifier then it should be diode protected and hopefully you are safe. However in my experience old gear has a habit of biting back as you have no idea what previous owners have done to it. A simple test is to check if you are getting an A/C ripple through the phono sockets. Old transformers break down like old guitar pickups do so be careful my friend :-)
She sounds great but please be careful mate,old valve gear can be very dodgy.
that piece of gear by itself is probably not going to be dangerous to you. The problem occurs because on vintage tube gear the grounding scheme was not particularly well thought out with respect to the AC mains "hot" and "neutral". If you have seen the comedy routine where someone touches a microphone while playing guitar and gets zapped then you have the correct picture in your mind. Plugging into your radio/amp can put your body at an electrical potential above ground. How far above ground depends on a number of factors. If you create a path to ground through your body by touching another piece of gear or something else metallic, then you will most likely experience a shock. The severity of the shock could be small, as in most cases, but the potential is there to create a life threatening condition. The fix is a "three prong" AC mains cord set. Its a pretty common modification to vintage gear. Its cheap and easy to do.
the main reason this isn't as easy as you want it to be is becaude each tube radio is wired differently. each schematic is different
sound good... But Please, tune your guitar !!!!
Can’t touch strings and electronics or metal on interior of amp or will shock you
6:13 no im allergic to cuteness
kewl video...who needs 3 grand for a tube amp eh? :D
you have to learn how these things works , the safety is important , its 300 vdc in there , find pages like ax 84
are you portuguese?
a guitar tuned isn't r'n'r !!!!!
well you need to know what youre doing if youre making a tube amp for guitars , there are still voltage in the amp even if you pull the cord , thats why there is no movie just do it like this out there , but if you want to make a amp read books about the subject , look at schematics how things work ,
Tune yourself.... that isn't too technical.. you can do it!
PLEASE watch 13 minutes of Uncle Doug here. czcams.com/video/xS_5K5YEYv8/video.html
Then switch the power cord with a 3 prong grounded one! Then cut out the death cap if it has one.
I am surprised you did not need a preamp of any kind. Now go feed Megan, she is cute as a bug and hungry.
Your American mains is not anywhere like our 230 volts in GB. Less likely to be lethal, but still needs to be treated with respect. The best thing isto keep one hand in your pocket as an old tech told me.
The theory is if you take the full force of a charged B+ filter capacitor or worst case the raw mains the charge will not cross your heart. Then the worst that happens is you drop a few F bombs & your daughter still has a daddy.
To turn the radio into a substitute guitar amplifier the radio should have a 'cold' chassis.
That means the filament supplies and the source of the B+ should come from a transformer. There should be no electrical connection between the mains plug & the chassis apart from a ground pin in a 3-pin plug. You need the circuit diagram for the radio to get this information.
If you are not skilled in valve amp work and high-voltage work I would not advise attempting the project.
Mutt amps he should have your answers good guy no bs!!!!
I used to play my guitar through an old tube radio back in the 70s. I did the same thing you are doing here, plugged it in through the record player jacks. It also sounded bad ass. I have no idea why it is supposed to be dangerous. I never got shocked.
Nice vid, but maybe you should start doing a little exercise 😀
Tune your gitar bro :)
Not even smart enough to be dangerous , more like stupid enough to be in danger . irritating.
Dont worry about electrocution,and if you dont have a phono input just solder a input jack to the volume pod,i been doing radio and transistor conversions for my cigarboxguitars for 20 years now and never had a problem
Wan't me to send you some cartridges, you know to help you fulfill your statement.
You don’t want to “fuck around with it” it will ‘fucking’ kill ya! Pay a professional.
10 mormons dislike this video for swearing ;) 106 likers don't give a flying shit ;D
you might not want to let your daughter touch the guitar and an earth ground. Even if it is turned off when plugged in you may have the same odds to letting her play with an electrical outlet.
Oh russians do it a lot!
Geez what a mess...
No offense dude, but for all our sakes...PLEASE TUNE YOUR GUITAR...otherwise, interesting project. Cheers!
don't apologize your language. one of the most beautiful real words in this full of fake shit era now. say it.
tune your instrument. god dammit
Just buy a real guitar amp, move its innards into a vintage radio of your choice.
Done.
Please buy a tuner the guitar was out of tune