Introduction: Music Visualizer (oscilloscope)

Picture of Music Visualizer (oscilloscope)
This musical visualizer provides an excellent way to add more depth to the experience of your music, and is quite easy to build. It also may be useful as an actual oscilloscope for some applications

all thats required is:
-an old crt (almost all b&w tv's work)
-some wire tape and pliers
-a bit of wire and an amplifier of some sort
-music to run threw zed amplifier
-basic electronics knowledge is helpful

ive got about 10 reports of success which is nice

I got the idea off of this site

this is a remake of my previous instructable for the art of sound contest and just to improve it

it can operate in 2 ways depending on how its configured, a horizontal line bent into waveforms, and a dot that expands into a squiggled up circle. both in sync with the music played. just look at the pictures and video

Step 1: The TV

Picture of The TV

a B&W TV should be easy to acquire at a yardsale, thrift store,maybe in someones trash, or probably somewhere in your house. It seems like most any b&w tv will work, but i have gotten reports of color tv's working (ive tried two to no avail), also a computer monitor can work too scorcher made an instructable on it

Once you have your TV carefully open it. You should see a big glass tube with a large circuit board under it. At the end of the tube close to you will see a few wires coming out of the tube connecting to the board (leave them alone) but ahead of them you should see thick coils of wires against the tube and 4 wires coming out near these coils somehow grouped into two on each side.

be careful as capacitors on the control board can store large charges for days, and the tube acts as a high voltage capacitor in most cases not lethal but dont take chances its still potentially lethal

Step 2: Make an Incision and Hook It Up

Picture of Make an Incision and Hook It Up

Cut any of those 4 wires identified in the last step then turn the tv back on

if you get a vertical line then you cut one of the horizontal coils wires
as you may have guessed a horizontal line means you cut the vertical coil
make a note of which is which

*there's no polarity with any of the wires

Now what you want to do is drive one of the coils with the wires that went to the vertical coil (the vertical supply) and put music into the other coil.
The easiest and most likely to work thing to do would be to leave the vertical supply hooked up to the vertical coil and put the music into the horizontal coil.
But you could hook the vertical supply up to the horizontal coil for a longer line I think that looks better but on my newer one that didnt work. Its hard to say how much less likely this is to work statistically its got a 50/50 chance it just depends on the tv you may try it if you like
also you could hook up both coils to your sound source for a dot that expands into a squiggly circle as i said on intro i just didnt like it as much

if you use the horizontal supply you get a flat line that moves up and down with the music which is pretty dull. this happens because the horizontal supply operates at a much higher frequency and pulls the electron beam back and forth so fast that the music dosent have any time to move it before its already crossed the screen

hopefully you can strip wires solder really isent necessary you can easily twist the wires together. taping over your connections is a good idea for insulation but i didnt even do that just make sure your wires arent contacting anything when you close up your case (or when your testing it)

once you have it the way you want it run wires off of the coil(s) your putting music into so you can close back up the case any wire will do speaker wire or whatever else just put it anywhere on the edge of the case as you seal it back up and it will be held in place(picture)

Step 3: Putting in the Music

Picture of Putting in the Music

The visualizer is basically another speaker for whatever amplification your using you may not want to use your most expensive amplifier
an average stereo or a guitar amplifier should do nicely or an amplifier from some computer

*theres no polarity for this either
put the coil in series with a speaker on your system if the volume has to be way up to get the line to move decently put the coil in Parallel with the speaker

Step 4: More Info

Picture of More Info

What your basically seeing is a constant series of graphs of something like 1 to .1 milliseconds of the vibration of the music

the vertical supply pulls the beam across the screen 100 to 1000 times per second the exact frequency depends on the TV. As the beam is crossing the screen the music signal pulls it up and down effectively drawing the waveform of the audio (at 100 to 1000hz(times per second)) giving you a dynamic view of sound hopefully thats a decent explanation.

if your brave enough you could attempt to make this
and get a pretty useful scientific tool from the looks of it, too much big scary circuity for me

a few ideas(no you dont have to follow this), you could use the volume potentiometer to adjust the output, build your own driver (sawtooth) if the driver circuity on the television refuses to work as it did on a color tv i tried, with a color tv possibly use a band filter and have the wave change colors depending on the frequency (see comments). if the driver circuitry refuses to work maybe a dummy load (resistor) across the horizontal drive would solve the problem(i think that was from a comment aswell). on certain tv's you may be able to twist the plastic that the deflection coils are wound on to get a horizontal line. feel free to post your own ideas in the comments

and also have fun with your oscilloscopeish audio visualizin thing


cardboarddude (author)2012-06-27

I opened up a small tv and connected an audio source to it, but the display only shows a horizontal bar that "fattens" with the music. It does not show waveforms. What did I do wrong?

IanB219 (author)cardboarddude2017-08-02

Try putting the horizontal coil on the vertical coil power wires.

ah sorry for the late reply. the problem is simple, you're using the horizontal coils output which operates at 17khz far too high for audio frequency, if you switch to putting signal into the vertical coil it should work fine.(if you want a horizontal line you can swap the coil drivers or rotate the whole coil assembly) tell me how it goes

alex.kogan.581 (author)2015-09-28

I've tried it with an old color Panasonic set, and found that disconnecting any of the four wires prevented the TV from switching-on altogether. Any ideas? (It works with a CRT display)

Ech0 (author)2015-08-08

How were you able to get that square wave displayed properly? So far on the tvs i have tried this with, square waves loose thiey're corners turning into sawtooth waves when using audio signals. Is this a current draw problem due to high inductance of tv coil? I would really love some help with this as it has had me stumped for a month.

Great instructable btw :)

420Bakerzdozen (author)2015-06-08

I really liek this idea! Can you do the same thing but with smoke instead of a TV?

sbliven1 (author)2013-01-10
Great instructable! I'm seeing some horizontal oscillations near the right side of the screen:

(A few overlapping traces from tapping a 6V DC source to the coil. You can see the oscillations on the faint traces to the right of the screen. More images on my blog post.)

Anyone have any ideas what could be causing it? The TV image looked normal before modifying the wiring.
tseay (author)sbliven12013-01-28

Try adjusting the horizontal and / or vertical position until you can see the whole wave form. To be able to change the size on the screen would be a good adjustment.
And dude (the 4th doctor) no dripping water glass by the equipment. Bad example. :/

sbliven1 (author)sbliven12013-01-10

Hmm, the preview showed an image but it seems to have been removed in the post.


DoctorCalabria (author)2012-04-14

Loved the project but especially the choice of tunes on yr vid! Keep up the good work.

imshanedulong (author)2011-11-11

I was unsuccessful in my first attempt. I think it's because i hooked it up in series to the second speaker instead if the amplifier. When I plugged it in it made noise and the screen had static.

So you attached it in series with one speaker of an amplifier? It should still work but the other channel will be very loud comparatively(but you could balance it out). Im not exactly sure what you mean though, did you have a solid line, and how did that line respond to input, also what were you inputting?

Good luck tell me about any developments

Before i plugged it in, I had a solid line. After, a bunch of static on screen and white noise in the speaker.

im just not following you here i need to know what was hooked up to what, if there's a good time you could go to the instructables irc we could probably figure this out quicker because i tend to be late in my responses to comments unfortunately

imshanedulong (author)2011-11-10

I am definitely trying trying this since antennae TVs like the one I have are now obsolete. You need a digital antennae now. This will work with a mini black and white TV right? Probably has non lethal capacitors too since its battery powered (12 volt I think)!

The 4th Doctor (author)2011-09-20

its great how many people are getting this working, a very rewarding instructable. just thought id mention that.

Jimmy Proton (author)2011-07-24

I tried this with a compute monitor and I get no picture on the screen when the horizontal coils are no hooked up properly but it dose make a lot of high frequency noises, Like you said up there, its just a flat line that moves up and down. Is there anything I can do about this or is it junk?

bears0 (author)2011-06-11

finally got mine working yesterday, i used one of those mini survival tv things thats handheld. it looks so cool.

The 4th Doctor (author)bears02011-06-12

Good stuff!

bears0 (author)2011-06-11

what are the names of the songs in the video from beginning to end, the only one i recognized was "smoke on the water".

The 4th Doctor (author)bears02011-06-12

Supernaught- Black Sabbath
Career Opportunitys- The Clash
Smoke on the Water- Deep Purple
Godzilla- Blue Oyster Cult
The Right Profile-The Clash
City of the Dead-The Clash
Highway Star-Deep Purple
White Light- Velvet Underground

Jimmy Proton (author)2011-03-22

Where did you get the tone generator you used in the video and how much was it?

marc666 (author)Jimmy Proton2011-04-03

NCH ToneGen, google it. its a very goor tonegen. I also believe audacity has one.

its from a computer going threw an old stereo, audacity has a tone generator. not sure how to do the sweep functions in audacity. i believe i was using some trail ware by NCH. certainly didn't pay anything.

marc666 (author)2011-01-26

its a very awesome project!
I now have a 2inch line in the middle of my screen, I know I have to adjust the V-hold, but cant find any potentiometer on the inside that seems to do something. there`s one on the outside, but this one doesnt work. the imge on the outside is something like this(image) would this be the Vhold adjuster and will it be broken or would it be something else?

greetings. Marc

The 4th Doctor (author)marc6662011-04-02

ah i am very very late. whats going on with it now, which supply are you using and have you rotated coils. the v-hold on the outside should be perfect, if it does not change anything i suspect you are operating on the horizontal coil. what happens when you input a signal. it could be that the tv's supply is unsuitable but that can be bypassed. anyhow i just need some information, after 3 months its probably been fixed or thrown out the window anyways. Sorry about that!

marc666 (author)The 4th Doctor2011-04-03

I got it working after a few weeks, its really awesome. I also forgot to say I got it working here:P. thanks alot for this great project once more. I have really enjoyed making it and I still enjoy looking at it.

ljarrald (author)2010-12-13

i have done this but it has not turned out like yours. i don't see waveforms, just the whole line mooving up and down, what have i done wrong?

The 4th Doctor (author)ljarrald2010-12-14

Simple problem, you are using the horizontal supply rather then the vertical supply. switch that and it should be good tell me how it turns out.

the horizontal supply's frequency is so high that audible frequency's don't have enough time to bend the line before it is drawn.

ljarrald (author)The 4th Doctor2010-12-15

i have swapped them round and it is BRILLIANT! only one problem, it is not across the full screen, only a portion of the middle, is there an way to overcome this?

The 4th Doctor (author)ljarrald2010-12-15

excellent, adjusting the v-hold makes a big difference, i usually get a small empty portion on one end though.

v-hold may be inside the case depending on the tv, tell me how it goes

ljarrald (author)The 4th Doctor2010-12-15

okay, i'll have a look tommorow and post a video, i am using a 5 inch portable tv but i did notice some sort of potentiometer inside, if i cant vind a v-hold adjuster what should i do?

WilliamRigney (author)2010-01-24

Will this work with one of those tiny portable tv's?

ljarrald (author)WilliamRigney2010-12-15

yes! i used a 5inch binatone minivision that my nana used to use to follow cooking programs in the kitchen, its just been sitting round doing nothing since the digital switchover here in the uk, i love the fact that this instructable has braught it back to life :)

hopefully, cant be sure until you try. in the 1st step theres a picture i got from someone of a portable tv that worked (it looks bad but he was just using a weak amp)

BrentFrench (author)2010-10-20

Great tutorial! I want to run a mic into the vertical coil, then place the mic in front of a guitar amplifier. Can I just split a regular mic cable and attach it to the coil, or would I need some other kind of cable?

A microphone would need to be amplified by some way, splitting the signal is fine.

its basically like having another speaker

highvoltage (author)2010-08-25

I build one from a 1992 color TV and it works great! Only took a couple minutes, easiest and most satisfying build I've done in some time! :D

kates6776 (author)2010-05-24

Hey, how exactly do I hook up an amplifier? It works, but it's really hard to see unless the music is loud, so it'd be nice to amp it up.

The 4th Doctor (author)kates67762010-05-25

well you can use any available second amplifier just make sure its nothing too valuable. split the input before the two amplifiers, use one for sound and one for the visual. or you could use the left/right balance of a stereo to make one channel with the visual louder then the other channel with the audio. any way that works.

kates6776 (author)The 4th Doctor2010-05-25

cool, thanks!

and thanks f making this instructable, it's such a fun project. :)

brrryan (author)2010-04-09

Would this work with a Commodore 64 monitor?

The 4th Doctor (author)brrryan2010-04-10

it might, something has to make it display a screen though

j03tv (author)2009-10-25

Ok, I found all the parts, but I still can't find Chippy! Where do I get one?

Seriously tho, can I do this on an LCD Monitor?
I have an old Viewsonic 19" widescreen that I don't use anymore and is taking up space from not being of any use.

k_man93 (author)j03tv2009-12-23

 ufortunately, no, you cannot... that would be awesome though

include DAN.h (author)2009-09-09

I didn't take the time to make sure all of the wires were right and the tv blew. :(

thats too bad, a few supply wires brushed together when i was trying this on a color tv and i blew its fuse

I was wrong and I got it working. :)

ReCreate (author)2009-10-17

I did it!
It only works if i use the horizontal(is that right) wires, that way, the line goes from the bottom up.
The other way, and it just does what it did in the video, It happened when i tried it with another CRT too.

The 4th Doctor (author)ReCreate2009-10-25

again sorry for the late reply, your comments keep slipping me somehow

good to hear you got it working, in that video you were using the horizontal coil driver (from the board) which operates at too high of a frequency (~17khz) to show waveforms in the audible spectrum

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