Build an Oscilloscope for £15 the DSO138 

It's a pleasure to see your work and listen to your explanations! You're great!

I don't have the skills to build one, but your video was well worth the time I spent on it. Your explanation of everything in this build is quite amazing. I think I shall buy the 'next one up' ready-built - it is on offer today for just over £20!

Thanks for your excellent report. Truly requires a skilled person to build it. Thanks for the Surface Mount Review. Very helpful.

Excellent video, full of useful and helpful hints and tips exactly what I wanted to know about building the oscilloscope. Thank you for sharing, much appreciated.

You Sir, are a wizard... I need to work a long time on my soldering before I can dream this big.

Very cool! Amazing how you found that fault, and got it working. Enjoyed this with my breakfast. Thanks for the video.

Awesome video, i like the way you explain things. I wonder if you can tell me if with one of these i can check a car alternator for bad diodes/ passing alternating current to the battery while running. Thanks!

Very interesting video, thanks for showing and please keep up the good work!

I did this a few months ago. Same model number. Works OK for basic stuff. I used solder paste and the hot air gun. The IC's I used the solder paste but used the iron to tack down one pin. I didn't have the problem you had. I wish it came in some sort of a case. I got a cheap metal case and mounted the O Scope, Capacitance/ impedance tester and Voltmeter in it. What is wrong with the Elenco XP-15K kit? The PCB burns past 8V The C2 Cap arcs and burns the board. I spread the trace apart as far as I could and got it to arc at 10V.

Great explanation on the resistor coding as well as mounting the SMD components ! I've never worked with SMD, so this was a good video to watch ;)

There are several cheap oscilloscopes..very useful..almost mandatory... they are very great and useful for clean signals.. but you will have to use your ears for high frequency noise and oscillations .. and then use a small capacitor to ground most of any possible noise heard.

Really great video. I managed to assembly one as well. For me it was a very nice soft of therapy work to solder all the SMD parts. But managed :) One tip is, when you get the acrylic case, build it up a few times _without_ tighten the nuts and bolts... THAT part took me forever to get done and yep, since I had to redo that part 3 times. First time I managed to forget to pull off the plastic cover from the display :D The second time I got a tiny little protection paper from the case sitting ON one of the knobs. Heh and yeah, the acrylic case is sensitive... managed to get a tiny crack in it(not seeable) due some misalignment, from my part and yep got a bit frustrated so I gave it a bit of a bash :) Anyhow, great one as always. Happy times are above us!

That knife! I see a call from down under on the horizon!

I made one. I like it. im sure people will scoff at the precision but for checking waveforms and quick analysis its great. also its portable!

Thanks for the video,i learn everytime i watch !

Brilliant video as usual Markus! I would love to build this myself. I've been using an Oscilloscope app so far with a Behringer UCA-202 for getting the audio in. However, I would probably get the Circuitboard with all the SMD's already on there. They're so ridiculously tiny and so is my patience. =D

Mine had a faulty transistor in the negative voltage generator circuit, fairly easy to find, not too difficult to remedy.

I built one and I am very happy with it, for the price. I bought it for less (yes it's an original) for £12.45 from Aliexpress. I also bought the acrylic case for about £4.50 but one piece had moved in the laser cutter and was misaligned. Fortunately it was not a critical part and I could discard it.

Bought a couple of these as they seemed cheapy and wasnt expecting them to work very well. I had a dud transistor on one which gave strange results. The diagrams on the manual do list various voltages at various test points on the diagrams, so I was able to track the fault down. I keep one indoors for odds and sods and one in the garage for car work. At £20 I'm not too bothered if it gets damaged.

Those testers never seem to test voltage regulators. I built this kit as well and it worked right away, but it started having trouble after it had been running for a while and I figured out that the 5 volt regulator was getting so hot it would burn me if I touched it, so I ordered some quality ones from Mouser and once replaced I had no other issues with it. I would say it isn't uncommon to have a bad regulator for these as they use cheap components.

Value to me as i build my own 138. Thanks!

I'm a Physics teacher who has stumbled upon your videos, and would you believe it I am short of oscilloscopes! I originally came to your channel for a teardown of drum machines I was interested in, but your channel is just fantastic. Really well made videos, you can see everything you want us to see. I love the videos fixing music equipment especially. I would really appreciate you going into detail about soldering components into PCB boards, with an explanation of technique for soldering. I know soldering is not a difficult thing but we all have our own ways, and I would appreciate your materials and technique. What power soldering iron you use for a PCB, what type of solder, how to clean and tin the soldering iron for beginners. It would be a video I would really value. I'm in the process of making a club at my school teaching pupils about electronics and making electronic things, so any help would be greatly appreciated.

What sort of tip for the soldering iron tip would make it slightly less of a hassle, a cone or wedge tip? thanks

i have the same, but pre-sholdered, how much max voltage input can i put on it with 1X probe. got it fully assambled original for 18 us$

The 7905 and 7805 are very static-sensitive. Could that have been the cause?

I've been needing a (portable) oscilloscope for my audio projects, but the usual ones are out of my budget. Definitely going to get this cute little thing. I only need to measure in the audible range so ;)

they're even cheaper now and thank for smd resistor value explanation

Soldering SMD parts is alot easier if you have 2 soldering irons. Also if you use the tips that curve at the end it helps to position the parts without needing a tweezers.

thank you for the video. do you recomend one of these for basic synthesizer calibration and testing? i am trying to learn to repair and service my synths, but want to stay in the low budget side.

There is an easy improvement that can be made to these (and it also applies to the smaller DSO138 "Mini" version). The waveform might look a little raggedy with high input signals. The reason is that the values in voltage divider R6, R7, and R8 are a bit too low and put a little too much load on the output of amplifier U2B. Since the divider feeds the high input impedance of the non-inverting input of U2C, you can easily raise those resistances. Just raise all of them ten times. R6 300 ohms becomes 3K. R7 180 ohms becomes 1.8K. And R8 120 ohms becomes 1.2K. Use 1% resistors. Also, I think nowadays they might all come with the SMD already mounted.

How can I use it with a synthesizer's audio out (3,5 mm) ?

I built one of these a while back, it has a fault, I'm gonna watch all of this later and see if your problem is the one you fixed, no spoilers please lol. Mine's a different fault. When trying to set it up (fixing the square wave display), the trace plummets when the required settings are selected and from memory (it's been a while) I think the signal drops low as I have to increase the scale. May be I'll have a lil tinker round with it one day.

Worth getting the case for it too

Heathkit...name from the past

Great video as always. can you link to where you got this Markus? Would be really great to have one coming out of my mixer for all my synths etc. Do you know if there is a stereo equivalent and whether it could be powered by batteries?

I've just bought one of these from banggood. Your not the first to experience problems with the screen . I hope mine works

Hey Markus :) I've had mine sitting here for about a month to solder up (only difference was mine came with a case - which I think they've 3D printed) - and the idea to use on synths was the same :) I was going to do a youtube video of me making it - but I decided my soldering skills wouldn't make for a good comedy ;)

hi Marcus did you have any trouble with the 8 volt rail ?

If I were to do this would my reflow gun help for the smd?

I think that it is sad that so many people can't be bothered to do something like assemble an electronics kit, it is a hugely educational thing to do. Saving a few £/$/€ is not the only reason for doing it. There is also an immense amount of satisfaction.

Excellent review! How many hours does it take to build it? Estimated. Enjoyed your trouble shooting skill !

I've bought one a year ago on Aliexpress. It had all SMT mounted, I just soldered through-hole. It even worked for a while, after I resoldered some obviously poor joints. And after few power-ups it just shows me blank screen with some rubbish pixels. Maybe there are more poor solderings I did. Dumped in a box for now. And sure, it's not for big engineering work, just to decorate some homebrewed synth.

+markusfuller you can get acrylic case for it from Aliexpress ;)

What a relieve to hear a 'normal' male voice... :)

I had lots´o´fun building mine....wrong resistor values, wrong designators...;) Of course i bought a SainSmart clone...but ever-since it runs nice and flawlessly. Let´s see what your build will turning out ;)

Do I detect a touch of knife envy with our friend at EEVblog?

Hi Markus, what is the temperature of the iron do you use to solder the SMDs? Thank you for you videos.

Good job ! Mine starts..white screen

Nice, inspiring video. I see over here you can buy a ready one (within a case) for 45 pounds (50 euro's, large, decent company). I think for those 20-25 pounds extra (case apparrently about 7 pounds) I wouldn't take the risk. No soldering skills, but nonetheless; these tiny parts, faulty parts etc. I estimate my chances on a working device less than 5%.

Marcus did you go to Uni to gain your expertise?

You said "in the audio spectrum" is that only up to 20kHz? If so, this if for me not useful at all, I need something that can handle like up to 600KHz or such. Can this do this or do you know any else/better but small and "cheap" thing just like this one?

Is this douable for a beginner?

You shoud have commented on the values of the capacitors.

I think you can not only attach this little thing to a synth, but to build a synth of your own... taking the best parts of the ones you've disassembled

I don't need one of these, but your video made me want one.

that is a great price for an oscope

Device rrecomended sir?

What kind of input connection is that? Will it take 3.5mm jacks?

An esd strap! 👍👍😀😀

I like your big knife, a la eev Dave

Too bad that this DIY-product is no longer available. :/

do you know if this can be set up as a X-Y inputs

Ive f'ed up 2 before i had a working one.

So I got your dso 138 oscilloscope as shown in this link. www.amazon.com/gp/product/B0195ZIURK/ref=od_aui_detailpages00?ie=UTF8&psc=1 I got it all put together no problem. Turned it on and tested it. It worked! (phew!) Then I get to tinkering with things, testing some of its own circuitry to look at voltage wave forms and whatnot. anyways, long story short, I think I shorted it. I was testing a 9v power supply, 2000 mA (which I now realize is way more than desired). But then I think I bridged R26 and R37 (on the right side near the power supply ports) and heard the 'zzt' sound that is oh so very very bad for electronics. The screen went white. I quickly unplugged it and hooked it up to the 9v battery that I'd been using. The screen still turns on but stays white, and the "trigged" led does not respond to any input, button pushes, switches, etc. How badly did i wreck it? Are there any suggestions on how i might fix it? (like maybe I just burned out a component that can be easily replaced (oh please oh please)). Thanks in advance if you have any useful information for me!

Hi Markus. I think you might have accidentally bought a counterfeit DSO 138. On the DSO 138 page on the JYE tech website there is a notice about how there are a lot of fake DSO 138's on the market right now. In the notice there is a link to a forum post in which multiple people state that banggood is one of the company's selling these counterfeits. Apparently some company named SainSmart replicated the exact design and is selling them for almost half the price of the original ones. Just thought you would like to know!

Had to click Like after he that package with a World of Warcraft dagger.

Actually not a bad idea to use the flux pen before soldering SMDs.

It lasted as long as an ice fish in a wiskey on the rocks. Sabina.

So you powered it up on a conductive antistatic mat and blame the component that shorted out on the mat? Never power up while on those mats.

Why is your bench covered in carpet?

yes I would agree, this is not a kit for the novice. those micro components would be a pain to solder.

Get smaller solder hehe :-)

You said zero- not zed! :). Are you slowly turning into an American?

Very limited functionality but what ridiculous value for money. I couldn't order a bare PCB for that price lol. Karl

太简单了吧，简直互动高中生的

Good grief! I can't even see surface mount components...

PEN KNIFE????

hmm...so the moral from this buildup is: never buy such complex kits....only professionals like you could fix it...a such a faulty component is really bad...how much was it already assembled ?

Some people buy a new car, other people buy a 10000€ Keysight DSO........

Save a life, surrender your knife.

I have to ask, as you have an oscilloscope that most people would give their right arm for, why are you bothering with junk. Is it just to make a video?

Opening mail with a big knife? Oh, come on dude, why do you try to copy eevblog? Why not think of something original?

An esd strap! 👍👍😀😀