Building the Largest 555 Timer in the World out of Vacuum Tubes

[@colinstu]

You should create a Datasheet for this crazy thing. Love this!

[@UsagiElectric]

Thank you! That's an excellent idea! Once the kit version gets further along and I'm quite happy with the characteristics, I absolutely would love to build a datasheet as if though it were a real IC!

[@neeneko]

@@UsagiElectric ooooh.. there are kits planned? and here I was just hoping that the pcb files would be posted.

[@jhoughjr1]

@@UsagiElectric a jazz tribute to chrono trigger. I see what you did there. Perfect choice for this

[@VoidHalo]

@@UsagiElectric A kit would be a fantastic idea. I remember that Monster 555 kit that was made with discrete transistors, and made to look like a giant 555 chip. That was a big deal at the time. Even Dave at EEVBlog did a video of him building one, and he doesn't like to do kit videos. So I KNOW that a kit version of this would sell like hot cakes. In fact, if the price point was right, I'd be tempted to buy 2 of them and make the world's largest Atari Punk Console. Or you could make a 556 kit with tubes and save me the trouble lol. =P

[@terawattyear]

Reminds me of the broken semiconductor part "Made in Japan" that Doc Brown in 1955 replaced with a jumble of tubes and wires such that the Delorean time machine could work again. Excellent idea and super execution! One of the first chips I ever used (back in 1983 in school) was the LMN555 timer chip.

[@VoidHalo]

It's proof that that could be done. Although it would have been very expensive. Transistors existed back then, but they would have probably been $20 or more a pop ($20 in 1955 dollars), I'd have to look it up. Although, Doc financed his science with some sort of inheritance, didn't he? I actually used to do something like this before I figured out where to buy ICs. I would TRY to wire up say, an XOR gate made with RTL (resistor transistor logic), which is about the simplest logic you can get. But still required several breadboards just for a half adder. Not to mention the rat's nest of wiring, but I'm sure that could be cleaned up.

[@RWBHere]

Back in 2955, point contact Germanium transistors were also fragile and noisy, @@VoidHalo!

[@kostaskotoulas6542]

Seeing it work so perfect as an oscillator made me think "somebody will use this design to make an analog synthesizer". Great job!

[@martinschroederglst]

Someone should notify LOOK MUM NO COMPUTER!

[@SimpleElectronics]

Wow, what can I even say about this - this thing is simply incredible! You've been punching far above your sub counter for a long time but this is something else altogether! "Cool" doesn't even start to explain it! Keep it up!

[@UsagiElectric]

Thank you so much! It turned out a whole lot better than I could have hoped for. Though, not shown are the months of testing and experimenting that led up to it actually working. Time to start work on the socket for this big boy!

[@OpalEckerDeRuvo]

This is not just amazing but also the most thorough, tactile, and intuitive way I have ever seen the 555 timer explained!!! I love it so much, it really makes a difference being abele to see the components 💖

[@joelpaddock5199]

5:07 seeing tubes and LEDs on the same board puts a big dopey grin on my face

[@andybytheway8785]

Brilliant project! I was taught valves in the 1960s but I have learnt so much more from you ... thank you, Usagi Electric :-)

[@UsagiElectric]

Thank you so much for checking the videos out! It means a lot to hear that people are getting something beneficial out of these videos!

[@Alsifnrbdvehrj]

This was the easiest to understand explanation for the 555 I have ever seen, thanks for this amazing video

[@antonnym214]

What a fun idea! Also very instructional for those of us who didn't know what goes on under the hood of a 555. All good wishes.

[@kevinmonceaux2101]

I have been binge watching this series, and am looking forward to the rest. For some reason near the posterior of this episode Mr. Spock in The City on the Edge of Forever popped into my mind saying, "I am endeavoring, ma'am, to construct a mnemonic memory circuit using stone knives and bearskins." A vacuum tube based 555 timer is a thing of beauty. Maybe I should have been born a decade or three earlier. I've been attracted to vacuum tube radios, TVs, etc., since I was a kid.

[@generalingwer4341]

Id be curious of what the rise and fall times are.awesome job!

[@QuanrumPresence]

You are inspiring me to build a vaccum tube circuit, as an electronic hobbyist I feel incomplete now!! I need to make a tube amp! Thanks for the amazing videos !

[@MrZenerTech]

When I saw those final waveforms, I immediately thought "textbook perfect"! Leaves me grinning with fond memories of my youth when studying 555 circuit design. Awesome project! Utterly impressive! What a fun project to geek out on with no real world need. Except the educational and entertainment value of course. 👍👍✌️✌️

[@greg4367]

Watching this makes me sure of two things. One, you are out of mind. Two, we would be very good friends. I love it!

[@UsagiElectric]

Thank you! And I have it on good authority that that Usagi Electric guy is a lunatic! Feel free to join the Discord if you want to chat about hilariously dumb projects like this: discord.com/invite/p7UsfHD

[@nsfeliz7825]

yap. such yhings come to mind for every engineer tech. but nope nope nope.

[@electronicengineer]

I recently discovered your channel via a KZbin recommendation. Your channel has taken the number one (1) place on my list of: "Best KZbin Recommendations" channel. As I catch up, watching every one of your amazing videos (it will take me quite some time), I have come to a conclusion that I have rarely come to over my fifty seven (57) years on this planet, observing other people, and that conclusion is that you sir are a true, full blown genius. I am honestly blown away by you. I just wanted to let you know. Oh yeah, by the way, I subscribed to this/your channel. I hope you don't mind! Fred

[@-Graham]

I did smirk when I realised the voltmeter was tube based too. I was waiting for the latch demo thinking "there'll be an LED indicator" Nope... VFD! Haha love it!

[@dans8287]

Good job! It's amazing how well the circuit duplicates the function of the 555. It must have taken quite a lot of work to come up with. I've been looking for content of experimenting with digital tube circuits with the focus on design for years. I haven't found anyone else doing this on you tube. Thank you for all your hard work with this. This is totally amazing!

[@UsagiElectric]

Thank you so much! I actually started trying to come up with a design for this months ago and hit a few walls I was struggling to wrap my head around. This caused me to shelve it while I let my subconscious chew on it. That made all the difference because when I came back to it, things started to click and I couldn't be happier with the result! Thank you for the awesome praise! Before I started the channel, I actually did the same thing, searching for digital tube circuits on KZbin (or even anywhere really), and there was a criminally low amount information out there. So, I figured why not share what I learn!

[@NowInAus]

What a gorgeous build and wow that astable output was razor sharp. Brilliant!

[@baronvonfritz]

Holy crap I recognized the song and threw me into a fit of nostalgia, had no idea this even existed! Thanks!

[@mezzofresh3521]

I absolutely love your videos man! I'm making a relay/digital computer from scratch and watching your stuff motivates me. Keep it going bro!

[@divyajnana]

Surprised at how SQUARE the square wave was (thought it would be "warmer"?). Great job, the art of electronics. And demonstrating using vacuum fluorescent display was a nice touch (never seen a VFD like that before.) Fun video, thank you.

[@possible-realities]

Well, the comparators / op amps use 6 tubes each, which should give them pretty high amplification, meaning that the comparators should be switching really quickly between maximum and minimum voltage. I think that's why it's so clean. The design had probably worked ok with fewer gain stages in the op amps, but then I imagine the square wave would have been more rounded.

[@sbalogh53]

Your enthusiasm is infectious. What an insane but awesome project.

[@coolbluelights]

my dude I said this in an electronics forum as a joke that someone should build a 555 timer out of vacuum tubes and you did it 3 years ago :D my hat is off to you! I personally got the idea I wonder if someone could build a smoke detector that uses vacuum tubes. how crazy would that be?

[@thegrassisntgreenertodaytony]

This video should have millions of views! Amazing. well done.

[@ijontichy6070]

Wow !!It is amazing for me ,to look on live tube circuit ! When I was young in about 1968 year ,I started to interesting in ham radio .Congratulations - Matt SP3FYI vy 73!

[@dave-j-k]

I love it - you have a 555 timer that needs to warm up :) Great video.

[@UsagiElectric]

Thank you! It's really fun while warming up too because all sorts of chaotic things happen as the tubes warm up at different rates!

[@-Graham]

Not only that but it's a 555 that works natively with higher voltages. No buffers or voltage translation required 👍 Surely there is a niche application where this might be useful? As long as power consumption is not an issue 🤷‍♂️

[@clarkinthedark1]

I would totally buy this as a kit. These kinds of experiments bring me glee. Well done!

[@MarcelHuguenin]

Dude! This is just a beautiful piece of art and it's functioning perfectly! I've been watching many of your videos and learned quite a bit from them and you have a great way of explaining. I had not seen using vacuum tubes with low voltages before and creating digital circuits with them but that's awesome. Great job!

[@LOOKMUMNOCOMPUTER]

amazing project!

[@UsagiElectric]

Thank you! I've been a huge fan of your content for a while, so pardon me while I walk away from the keyboard and fangirl a bit about you seeing one of my videos, haha.

[@LOOKMUMNOCOMPUTER]

you are definitely on to something with a plan of a kit! cool idea! let us know when its up and out! i'll happily share on socials! its awesome ha. looks like it would make a cool kit! only bit that might need thinking about is the legs. looking if there is already a manufactured component that could be put in place of them for easy kit component sourcing for you. like some sort of 90 degree hinge or something no idea lol. just a thought.

[@UsagiElectric]

@@LOOKMUMNOCOMPUTER Thank you! I've been working on re-designing the OpAmp to bring the tube count down a bit, as well as give it enough adjustability to be used with a few different tubes. I think I'm getting pretty close a finalized design I like, so I'm just waiting on some parts to come in so I can properly test it. But, as you guessed, the legs are the big one. Nails haphazardly soldered in and then chunks of steel spot welded in is so perfectly Mad Max, but isn't the greatest solution, haha. I would like to keep the legs conductive, so oversized sockets can be made in the future, so I have some ideas for tackling that. Currently, I think my best bet is going to be to design up the legs in the right shape, and then get them laser cut out. There's still a lot of hurdles with that approach, but if it goes well, that could be a tidy solution! I do like the idea of a 90 degree part hanging off the edge though. That might prove to be easier to handle and give a cleaner solution. Hmm, I'll have to do some more investigating!

[@WagonLoads]

WOW, the 2 guys I was wanting to talk to about this... I fed the triangle wave output of a 555 timer into one input of a comparator and a pot(analog) into the other input of the comparator. The result was a variable PWM generator... With the input range equal to the 1/3 - 2/3 voltage of the divider, you can go from 0% to 100% duty cycle on the PWM output. My intention was to make a PWM speed controller for an electric car...

[@LOOKMUMNOCOMPUTER]

@@UsagiElectric good luck with it all!!!!!! let us know when the kits are sorta ready and you have a plan for selling on your store or kickstarter or whatever. would love to give em a go!!!!!!!!! proper cool haha

[@thirstyCactus]

This is awesome, running the whole unit with a single, safe supply voltage. I didn't think such a thing possible! Next challenge: accomplish the same functionality with ~half the number of the stages 😃

[@90FF1]

The entire video enhanced with your enthusiasm kept a smile on my face. Although I was a bit disappointed not seeing a CNC plasma cutting out the legs. :-) Absolutely beautiful in every way.

[@UsagiElectric]

Thank you so much! It means a lot to hear that y'all are enjoying the videos as much as I'm enjoying making them! A CNC plasma cutter is on my wish list of tools I "need", it would have made making the legs so much easier. For the kit version, I think I will get the legs CNC cut, but I'll get a service like OshCut or someone to do them for me. From a circuit standpoint, I think I'm approaching a design that'll work pretty well. I'm just waiting on some parts to arrive so I can start designing the PCB appropriately.

[@joewoodchuck3824]

I love it! I came from the tube era. They were still being taught in tech school when I graduated in 1967, but we got transistor theory alongside. I hope it dissipates at least a few hundred watts!

[@UsagiElectric]

Thank you! Not quite a few hundred watts, haha. The heaters pull the most juice and I did a little math to come out to right around 50W of power, which is massive by today's standards, but for complex tube circuits, not all that bad!

[@Chicken_Massacre]

@@UsagiElectric You made a nice but power hungry 555 😂 I love it.

[@dennisyoung4631]

Tubes were still being taught up into the early eighties, at least where I went to high school and then college.

[@joewoodchuck3824]

@@dennisyoung4631 I wish I could remember when tubes and testers disappeared from Radio Shack and drug stores. There's just something wonderful about that dim amber glow ...

[@russliquid4858]

u are awesome! you break the stereotype of electronics genius, specifically: wonderful personality and a gifted communicator. Thank you for sharing your knowledge! I just started my journey into the awesome world of electronics, especially the analog & 70-80s style logic vibe... Tubes scare me a lil and i find its not easy to find information that is modern in its delivery that doesn't make me wanna run the other way ha.... thank you thank you thank you for sharring!

[@Simon_Rafferty]

That's really cool - good explanation of the original 555 pins & function too.

[@UsagiElectric]

Thank you so much! The 555 is such a cool chip and has a really neat design!

[@vangalvin]

Awesome project :) Now build a tube version of a 4017, thow in some Diode valve's and use some VFD's to build a valve version of the night rider scanning eye :)

[@UsagiElectric]

Thank you! Decade counters are really tricky with tubes! I haven't had much luck at low voltages getting a good toggle flip flop working, but at higher voltages, HP had a really great design for a decade counter: madrona.ca/e/edte/HP520/index.html One of these days I'll have to dive into that circuit design and see if I can make it work at the low voltages I'm working at!

[@tjwatts100]

4017: my favourite chip.

[@retrobitstv]

This is freakin' awesome! I love everything about this project as well as your enthusiasm. Keep it up, you mad scientist!

[@UsagiElectric]

Thank you! It's not often I can sit down and take an iconic IC and make it worse in every metric except for how awesome it looks, haha.

[@retrobitstv]

@@UsagiElectric I think that's called "art" :)

[@hamradio3716]

Nicely done. Your CNC machine really makes nice PCBs!

[@UsagiElectric]

Thank you! I love that little Bridgeport!

[@plasmar1]

I was reno'ing my sisters old room and found a 555 timer in original radioshack realistic packaging pinned to a stud.... they're everywhere!

[@carnright]

LOL love the rabbit for scale! This would make a great kit as it is not just a put all this together and you have a 555 timer, because of all the sections and the videos for each section you have it can be a real learning tool :-) If I were to follow along I would want to think of Electron flow and of conductors rather than resistors :-D

[@UsagiElectric]

The bunny wasn't quite sure just what to think of the monstrosity before her, haha. That's a great idea, making specific videos about how each portion of the kit works as we build it up! Once the kit gets further along in development, I'll definitely start authoring up some tutorial videos.

[@KeritechElectronics]

This is absolutely brilliant! Including the pins and all that. I love your PCB design, with rounded corners on tracks.

[@UsagiElectric]

Thank you so much! I really wanted it to be as close to pin compatible as possible, though I did have to sacrifice the control pin to get my negative bias voltage in. The rounded corners are probably my favorite part of the PCB design. I especially like it when there's two or three traces that follow the same curve, it gives a really unique look. It's kind of my modern, digital homage to the hand-drawn traces of yesteryear!

[@KeritechElectronics]

@@UsagiElectric yes, I know the old PCB design from all those radios and amps I repaired :) And in my early days in electronics (1990s/2000s or so) I did hand-drawn PCB designs, then etched them with ferric chloride or a mix of hydrogen peroxide and muriatic acid. I hardly ever make devices using PCB as I prefer the old point-to-point style and terminal boards (most of the electronic stuff I make is vacuum tube amps), but when I do, I typically do it in Eagle and either have the design CNC engraved like you do, or take it to a PCB manufacturing company and have all SMD parts soldered in so that all I have to do is through-hole components. Oh, and your wascally wabbit is so sweet! :)

[@UsagiElectric]

@@KeritechElectronics I have massive respect for anyone that actually etched PCBs with acid! I'm so accident prone, that I'm absolutely terrified of knocking the container and spilling chemicals everywhere. Fortauntely, with the mill, I just get everything zero'd out, hit Go and then walk away so my accident prone-ness can't mess anything up, haha. If you want, come join us over on the Discord chat group, I would absolutely love to see some of the tube amps that you've built! (Link just in case discord.com/invite/p7UsfHD ) The bunnies name is Koma, which is short for "Komaru or 困る" which roughly translates to troublesome. She was so energetic when she was younger that she would run full speed all around the room and crash into things, knocking stuff over and generally causing chaos, so the name is a bit of a fitting choice, haha.

[@cellularmitosis2]

Love the enthusiasm! Electronics vids need more of this!

[@juntendo6104]

amazing piece of art! I like how you use VFDs instead of regular leds.

[@fabioeleuterio143]

That's the kind of thing I would never think someone would ever build... Amazing!

[@mac_edmarco]

this is the coolest video ive seen in a while! Bout to go down a rabbit hole of all your videos!

[@-Graham]

Late to the party but... This is really cool! And I absolutely love your enthusiasm! It's infectious 😁 I'd love a kit or at least a PCB file so I can source my own tubes and build one. I have always been a little afraid to mess with vacuum tubes, the mode of operation has never quite sunk in until I watched this vid. You have a great way of visualising and explaining! This is the first video I've seen of yours and you've definitely earned my sub. I am looking forward to pouring through your channel. Thankyou 👍

[@MadScientistGuitarLab]

I love how excited you get making stuff. :)) Now you have me thinking of making a vacuum tube drive CNC machine that would make turret boards. :D

[@UsagiElectric]

Thank you so much! I can't help but get excited whenever the electrons go where I want them to, haha. A tube driven CNC machine would be absolutely epic! Definitely keep me updated on that project if you ever decided to dive into it!

[@gwynnej3]

I love the delight and excitement when it works! Excellent.

[@jacomostert4413]

Fantastic! Lovit. Socket would be cool! Alternatively maybe an umbilical cord kind of thing which ends in a socket, which you plug into a standard breadboard?

[@CountryBoy4ever]

I want a kit. The triple nickel timer is one of the first chips I learned about while getting into electronics. I used 2 of them to make a remote start for my car with very interesting results.

[@tammasus]

That’s beautiful visually and functionally. Thank you

[@arrbam02]

Awesome! Made my day! If you want to make an affordable kit, think long and hard about the tube type, because that's going to make the biggest differernce price-wise. Select something that causes audiophiles to cringe. Something made in abundance at one time and then not used for another purpose, like a TV video amplifier or something like that. In europe we have the Pxx type tubes, these are usually dirt cheap. I really like the physical format and how it looks like a scaled up version of the real thing, don't change that!

[@UsagiElectric]

Thank you! Figuring out the tube type has been the biggest hurdle to overcome. My go-to tube is the 6AU6 as it works really well at low voltages and is very cheap indeed (aside from using it for pre-amps, it's mostly ignored by the audio community. However, I realize that that tube may not be easy to find depending on where someone is in the world (or even how the used market is feeling on a specific day). So, I've been working on an OpAmp design that only uses 4 tubes (instead of 6) and has some potentiometers in it to tune it to different tubes. So far, I've got it working pretty well with 6136, 6AU6, 6CB6 and 6DT6 tubes. Some others like the 6BA6 didn't work at all, so we still have to pick the right tubes. But, having more tube options is always better!

[@dungareesareforfools]

There are a lot of cheap 6F1Ps on eBay, if triodes can also be worked into the design!

[@gandalf87264]

If you make the kit, I will buy it. It will probably be the most expensive 555 I have ever bought, but I think it would be worth it.

[@DigitalAndInnovation]

I love how excited he is about it working! I would be too!

[@ThatJay283]

i think it's really neat that you didn't use any leds! so perfectly demonstrating that all that new technology isn't actually needed lmao.

[@adailyllama4786]

I really enjoy the retrotech to IC builds! This one is incredibly cool!

[@UsagiElectric]

Thank you so much! I've actually got another coming up soon that I'm quite excited about!

[@antonnym214]

YES, you not only need a socket, but a package to enclose the circuit in, just like a 555, and have a picture of a rabbit on it, and "U-555" for Usagi Electric

[@davidciaffa4711]

Cool project! Just one minor nit-pick - you have the operation of the monostable backward. At rest, the cap is held in a discharged state by the discharge pin. When the 555 is triggered, the discharge tube/transistor turns off, which allows the cap to charge toward Vcc. Once the voltage reaches 2/3 Vcc, the threshold comparator resets the flip-flop which turns the discharge device back on, discharging the cap in preparation for the next trigger event.

[@UsagiElectric]

Thank you! I knew I'd make a mistake somewhere on the 555 timer side, haha. That makes sense though, thanks for letting me know!

[@clifffiftytwo]

AWESOME! And the artistic rendering is the icing on the cake. Please, a kit - of course creating that is another work of art as well.

[@UsagiElectric]

Thank you! Making it a kit is going to be a definite hurdle. I would like to perhaps shift the used tube from the 6AU6 to the 6CB6, but that's going to require a redesign of the OpAmps. And since I'll be redesigning them, I'd like to see if I can get them down to four tubes instead of six, that'll save a decent amount in terms of materials cost. So, it's a long road, but I think the result can be something really cool!

[@wtechboy18]

Have you done any kind of test on what the maximum response frequency is on this thing? I'd be curious how well this holds up against an actual 555 timer.

[@scotty3114]

Very cool. Yes, I think a vt-555 kit would be awesome!

[@generalingwer4341]

Thats classic,i cant think of more comparable idea.greatvideo!

[@Peter_S_]

This is absolutely outstanding! Hats off to you!

[@UsagiElectric]

Thank you so much!

[@KanalFrump]

This is fantastic! I actually got a better appreciation for the 555 out of your clear explanation. Neat build. Make that socket!

[@aliaslam2454]

Tel me advice me ihave a metal gang with two side of 500pf value iwant to use ic circute fm radio .How meny value of pf condenser to oscilate.

[@greenalien8503]

Holy crap that looks absolutely amazing, that would look beautiful to display too, crazy good job man

[@UsagiElectric]

Thank you so much! I'm quite happy with how it turned out, and I'm hoping that once I build up a socket for it, it'll make a great display piece for the collection!

[@deemstyle]

Wow! Just discovering this, but absolutely blown away! Please tell me you did end up making a kit out of this. Or at least making the PCB artwork available with a parts list!

[@video99couk]

I've found that the 555 reset operation is not very well defined. In astable mode, some 555 devices will halt the output high or low depending which it was when reset was applied. Others send the output always high, yet others send the output always low. I wonder which camp this one falls into.

[@neillcoetzer9133]

Great videos. Some years back I got suuuuper interested in vacuum tubes. But shipping to South Africa along with difficulty of actually getting into it kept me out of it. So I've only ever worked with Nixie tubes. This is however reinvigorating my desire to work with vacuum tubes again hahaha

[@yz250ftony]

What's the upper frequency limit in astable mode? higher than the 555? Next step would be using this to make a signal generator based on it. Think you can get a sine out of it?

[@flash001USA]

Just curious what it's bandwidth limitations are or how it's bandwidth compares to the solid state 555 timer?

[@UsagiElectric]

Naturally, it's a way, way more limited than the solid state 555. I did actually give it a test in astable to see just how quick I could push it, and it seems that 8kHz is about the limit. It will actually go faster, but the falling edge starts to fall too slow and the output waveform gets smaller and smaller. You can see the slow falling edge here: i.postimg.cc/fRBJ9Nx6/IMAG3517.jpg Still, for such a compromised design, that's not bad at all!

[@flash001USA]

@@UsagiElectric I'll check out the link. Yeah I can see the limitations exactly the way you're describing them due to the components you used for the project but the fact you even built this with tube technology is pretty cool.

[@DIYTAO]

With some extra control logic, that latest circuit would make monophonic all tube synthesizer. I'm sure some people would be interested if you'd made those.

[@UsagiElectric]

Interestingly, I've recently done a bit of testing with a 2D21 Thyratron as an oscillator. Here's the setup I was testing out: i.postimg.cc/gkRW6n8J/2D21-Osc.png It generates a really great sawtooth wave, like this: i.postimg.cc/fbSjwn16/IMAG3460.jpg And when input into an inverting amplifier it makes an excellent square wave. With potentiomters on the 2D21 for the plate resistor and the grid resistor, the sawtooth pattern can be changed pretty dramatically, changing the shape of the square wave. That could make a really interesting tube synthesizer circuit with both a sawtooth wave and square wave on tap!

[@techtinkerin]

That is definitely the most Doc brown thing I've seen for a while!! 😎👍❤️

[@CoolDudeClem]

"At least 1", I have at least 100! I ordered several of them a while back, thinking I was ordering individual chips, turns out I was wrong and got several bags of 555's instead! Oh well, live and learn, at least I won't run out for a while.

[@PurityVendetta]

What a fab channel, I've only just discovered you. Liked and subbed.

[@256byteram]

So glad Hackaday did an article about this! I didn't know this channel existed. I'm sure there'd be people out there who'd love a kit for it. Need to get the tube count down though! I notice your go-to tube is the 6AU6. Mine's the 6BL8 because it has a pentode and triode in the same package. I usually use the pentode for gain and the triode to buffer the output - however I run my projects at 250V, so that'd make it easier for them to operate. Probably not recommended haha. Good work!

[@UsagiElectric]

Thank you so much! The 6AU6 is indeed my go to tube, but mostly that's because it's cheap, I have a bunch of them and I've done enough with them to be really familiar with how they react. I actually have a handful of triode/pentode combos (notably the 6GH8, 6KT8 and 6GJ7), and they would make excellent gain buffer combos like you use with the 6BL8. I do use the 6AU6 as a cathode follower buffer for the output buffer on this one, but I totally could have built the flip flop and output buffer using just two triode/pentode combos with relative ease (and halved the tube count on that portion). But, as you noted, running at such low voltages makes things a little more difficult! Running at 250V would work so much better, though I'm guaranteed to have shocked myself more than a couple of times by now if I were, haha.

[@256byteram]

@@UsagiElectric While I think of it, it should be possible to get a very low anode voltage on a triode if you drive the grid positive relative to the cathode. This means grid current will flow so the source impedance needs to be fairly low. It'll behave like a pentode with a 0V grid sort of. Something to think about. Cheers.

[@UsagiElectric]

@@256byteram Interestingly, driving the grid slightly positive relative to the cathode is how most of my low voltage designs work. Even with the pentodes, I tend to push the grid to just above 0V to fully drive the tube into saturation. The grid does suck up some electrons, but there's enough resistance on the grid network to keep that to a minimum. It's kind of using the tube outside of it's intended design, but then again, rocking just 24V would make most of the tube designers of yesteryear just look at me like I was a mental case, haha.

[@DolezalPetr]

what PCB hollow pin sockets do you use for the vacuum tubes to plug into?

[@gandalf87264]

Here is an idea: Instead of making a socket for the valve chip, simply lengthen the rods that the legs are soldered to. I will make a PCB footprints for the chip and the extra large components I will make for it. I will 3D print super large bodies for the resistors and capacitors proportional to the size of the chip and place the real components inside them. It will take a sizable chunk of copper clad and the solder alone would probably make the board weigh an extra kilogram,, but I think it would look stunning in the end. Here is a challenge for you, JLCPCB.

[@meepk633]

It's the first IC I bought and I bought 100 of them. I use them for everything. Triggers, timers, pulse gens, simple choppers for converters, comparators, etc.

[@UsagiElectric]

The 555 timer is truly one of the most versatile IC chips on the planet! I've seen people do really wild things with them, like building full adders, or getting relatively complex behavior in Beam robotics. They're such a timeless design, and when mixed with how affordable and plentiful they are, it really got the engineers thinking of some great uses for them!

[@NCommander]

Damn, this is impressive. Seeing tubes makes me happy as well as explaining it.

[@UsagiElectric]

Thank you! There's something super satisfying about working with tubes, I'm so glad that there are others out there who share my rather niche joy!

[@speedbuggy16v]

This is one of the coolest, and dumbest things I have ever seen. In short, I love it! Definitely needs a socket. A kit would be awesome, especially if you came up with other projects to specifically use it with.

[@joaomarcelobadu]

Congrats, well done! This is so cool that I would make one just for fun!

[@UsagiElectric]

Thank you so much! I hope to come up with a good kit design that can be easily built by anyone, but there's still a lot of optimization and thinking to do. I've got a lot of ideas I'm working out the kinks on though, so hopefully we can come up with something that works great and is decently affordable!

[@babygorilla4233]

This guy's getting ready for if the sun gets angry at semiconductors.

[@Nepermath]

Sir, i Love what you made, with fantastic 555, now made by you with tubes, congratulations!!! 🤗🤗🤗

[@UsagiElectric]

Thank you so much!

[@gerhardhager2376]

Great Video to understand technical progress. Amazing.

[@VoidHalo]

I discovered that the NE555 seems to have no protection diodes. You can put a multimeter in resistance mode across VCC and Control to get the resistance of R1. And between Control and Ground gives you R2 + R3. Interestingly, the chips I have all have 6k resistors in them rather than 5k. That is, I got 6k across VCC and CTL and 12k across CTL and GND. I figure this is down to the fact that it's difficult to get exact values on resistors in an IC. So, the circuits tend to rely more on the ratio of resistances, rather than exact values.

[@ostsan8598]

The HL666 timer. In an alternate universe where integrated circuits never developed, this is the single most used hollow logic chip in hobbyist circles.

[@richardhansen469]

This is so cool, I have to dig out my old Radio Shack "designers handbook" pamphlet of 555 projects. I can make an LED flasher out of it! I'll definitely take a tubeless kit if that comes to be, I have plenty of sharp cutoff pentodes.

[@UsagiElectric]

Thank you! I'm really happy with how it turned out! I'm definitely thinking about designing a few kits, one for pentodes, one for dual triodes, as well as coming with tubes and without tubes. I'm trying to do as much testing with and design revisions as possible with different tubes here to make the design flexible enough to be used with a variety of different tubes (and also to bring the total tube count down a little). Out of curiosity, what kind of pentodes do you have? My hope is to test and design with enough different tubes that I can release tubeless versions with recommended tubes and resistor values.

[@richardhansen469]

@@UsagiElectric check out the .75 cent Tubes list at vacuumtubes.net. There are many small TV pentodes that nobody wants because they don't work well for audio, but for this would be fine. You'd be under $18 for all the Tubes with shipping.

[@UsagiElectric]

@@richardhansen469 I really do need to contact them! Unfortunately, all of my go to tubes for the low voltage applications that I'm doing here aren't in there specials category (6AU6, 6AS5, 6136, 6BA6, 6CL6, 6BK5, and maybe the 6CB6). They do have the 6DT6 though, which I do happen to have in my collection, so I can do some testing with that one. I need to dig through their list of special cheap tubes and see what I have on hand to do some testing with!

[@recramorcenlemniscate7945]

The really cool thing is that vacuum tubes technology can operate at higher voltages & wattages than their digital counterparts. So you could make a high voltage computer & high frequency oscillator/timer.

[@adnanyavuz8836]

Thank you very much for broadcasting this tecnical video..I mean that it is very usefully for me..Thanks again...

[@UsagiElectric]

Thank you for checking the video out!

[@jonka1]

Have you tried playing with the voltages on G3 @5:52 to see if it affects the degree of capacitor discharge available?

[@holden0]

Kudos, very interesting approach to a 555!

[@weirdboyjim]

Awesome achievement! You make me feel bad that I use a whole 555 timer to de-bounce my step button. Put me down for a kit when you are ready!

[@UsagiElectric]

Thank you so much! We'll have to find a way to integrate a tube into your 8-bit machine one of these days, haha!

[@weirdboyjim]

@@UsagiElectric You keep those nasty high voltages away from my baby!

[@UsagiElectric]

@@weirdboyjim Hmm, building a tube circuit purely at 5V, that may be a challenge worth undertaking!

[@4stsims]

At 22:26 you display a tube that illuminates green. What is that tube?

[@mikebrown1970]

Cool project! If I built this I would like to use a small relay for the discharge. When it works as an oscillator, you can hear the relay ticking XD

[@UsagiElectric]

Thank you! Interestingly, I actually tried prototyping in a relay for the discharge portion of the timer. I had a few issues with getting it working just right. The relay needed a lot more current than my low voltage tubes could reliably supply. I needed to run two to three tubes in parallel as cathode followers to reliably kick off the relay. But then, I couldn't bring the voltage low enough to turn off the relay, since the maintain voltage seemed to be quite a bit lower than I expected. Of course, I was just using a random small relay I had laying around, so it could probably work a bit better with a properly sized and rated relay. Another thing that I want to try for the discharge is using a 2D21 Thyraton instead of a 6AU6 pentode. I think that would be able to really discharge something to completely zero (though using a thyratron brings with it its own hurdles).

[@bob4analog]

Can you tell what the number the VFD tube is?

[@UsagiElectric]

The VFD I used here is a Russian made IV-15, which is a copy of the DM-160. Searches for either should bring up plenty of results!

[@bob4analog]

@@UsagiElectric Found em, thanks!

[@davidvincent8929]

MIND BLOWING, SIR. IMPRESSIVE. THANK YOU.

[@ad5mq]

that is fantastic, I agree with the datasheet comment, and I would totally be interested in a kit. I suspect I can even supply my own tubes.

[@UsagiElectric]

Thank you so much! I've been working on a design for the OpAmps that uses just 4 tubes each (instead of 6 each), but is still flexible enough to be used with a few different tubes. So far, I've got it working pretty well with 6136, 6AU6, 6CB6 and 6DT6 tubes. There will be two little potentiometers to tune the OpAmp to the tube type being used, hopefully opening the kit up to a bit more flexibility for sourcing tubes. Now, I'm just waiting on some ordered parts so I can start proper design on the PCBs!

[@russliquid4858]

is the music from andrew bird? (during build montage?)

[@orinokonx01]

You're like Doc Brown, when he fixes the time circuits on the Delorean with valves! Certainly have the hair for it :D

[@UsagiElectric]

Haha, you should have seen the hair before the haircut! kzbin.info/www/bejne/npi5loiZismHbJo

[@rearspeaker6364]

and this looks like it came from Bletchley Park! cute bun bun!