Vacuum Tube Amplifier
January 14, 2026 • EPISODE 293
📌 Science Fair Idea – R-51 Radio
What’s a vacuum tube amplifier? Come explore with Dr. Roger Billings on Science LIVE! Learn about the technology that made it possible to boost electrical signals and amplify sound. Discover how vacuum tubes control electron flow, why they powered early radios, audio systems, and computers, and how they shaped modern electronics. And get ready for something super exciting: carbon nanotubes – super-strong, lightweight materials that might one day help build a space elevator, opening new ways to reach space!

About DrB
Dr. Roger Billings is a visionary innovator whose work has touched the lives of millions of students and transformed the landscape of education. Widely known as “DrB” to the countless kids who benefit from his groundbreaking Acellus learning system, Dr. Billings has dedicated his life to advancing education through technology.
As part of DrB’s lifelong commitment to supporting education, Science LIVE was launched as a way to “give back” by mentoring students in conjunction with the Roger Billings Scholarship Program.
Read more about DrB »
About the Roger Billings Scholarship Program »



I’m excited for Acellus World!
I love how fun it is to learn things from science live
R 51 is so funny!
I like watching science live with my mom
I love how fun it is to learn things from science live!
I am up bright and early to listen and watch science live while I paint!!
Carbon nano tubes are a strong and light material that can be used for many things.
Space elevators would be so awesome! Maybe someday.
R51 is so funny
I LOVE R51
I enjoyed the part about the cups. Thank you for the lesson
I 💗 SCIENCE LIVES
im watching the live from nova scotia canada
honesty is always best!
The carbon-nano tubes are a thing of sci-fi they are amazing. Great look into the future of science.
I learned that carbon nano tubes are 100 times more stronger than steel and longer than the denominator. I also learned that carbon nano tubes are conductive of electricity and heat. Amplifiers are really useful when it comes to technology. Carbon nano tubes can change the world. Talking through cups is pretty cool as well.
The vacuum tube amplifier heats the cathode to release electrons, forming an electron flow. The input signal voltage changes the grid potential, thereby regulating the flow of electrons to the anode. The electron flow is then converted into an amplified voltage signal on the anode load resistor.
I love that Science Live is back! I’ve made tin can phones when I was little too R51.
Science live is the best!
It was very interesting how the such a small amount of volume age or power can move or do such big things. Like the amplifier can make a concert for 2 into 2 million it makes the music so loud. Who knew that was a thing that so little power yet it goes long way. The power from a stop light stops truck and it is not very powerful it shows that you don’t have to powerful just be effective.
Science live inspires me.
the science fair sounds so interesting! and R51 is my favorite part of science live
I honestly have never heard of a Nano Tube. Nor did I think they’d plan to make a tube to space!!
I really enjoyed learning about vacuum tubes.
How strong is the carbon nano tube?
I LOVE R51
So cool to learn about how the flash memory was created! LOVEEEE science live!
Do you think there will ever be filters that will get harmless bacteria out of the air?
Is the science fair going to be located in Kansas City like the other Acellus actvities?
Yes I have been doing acellus for almost 3 years
I learned how amplifiers make things louder.
we loved this weeks science live!
how do we find out more about the science fair?
Can’t wait for the next one Wednesdays are my favorite day now !
I love science lives, I always learn something really interesting
I want to meet Dr. Monet!
Thank you for allowing us to watch science live a few days later when we need to.
Didn’t know how vacuum tube amplifiers worked until now.
I like watching Area 51 they are funny
This week we took a field trip to the beach and learned about the different species we saw!
Hello, Kai from South Daokta!
Excited be back after winter break! Love science live!
Where and when is the science fair
Dishonesty destroys our character and our credibility.
Loving this all from Hawaii!!!
Honesty is always important!
Hello from Arkansas, I love Science Live!
I love science it’s one of my favorite subjects!
Science live helps everybody learn something new and that’s something I appreciate! Thank you guys for helping everyone understand things better!
Hello from Mississippi thank you for the videos.
I love science
Can’t wait for a new science video!
This was so intriguing!
This episode is so cool!
Fire making water, woww…so great. Science is a search for truth, love it. Thanks R51.
I love science!
congratulation for the students graduated from Accellus
Honesty is a key. Love your story, very inspirational for us. R51 great.
i love the design of the hydrogen car
I love these science videos for school. Im listening from alabama
I looooove science livesss <3
I love watching the science experiments!
A space elevator sounds so cool!
Interesting, I wish Dr. John would have gotten to talk more about the space elevator. I really like that idea.
Such a great live!
Watching from pueblo West Colorado
Vacuum tube amplifiers are so cool
This was very educational about science thank you.
Science live is fun
Science live was amazing!! Watched it kind of late but I learned a lot and hydrogen car seems fun, Acellus is a great online school
this was awesome!
Science Live always inspires me to be more curious about how other things were invented.
Cool science live
beyond awsome
I liked when you talked about being honest as a scientist. I think that’s very important.
Area 51 is so funny
Love watching!!!
Acellus World sounds awesome! I hope I get to attend one someday. Are these held every year?
Sounds amazing!
Really great episode!
I really love learning about the origins of the technology we use today!
Love this
It’s neat how amplifiers work!
The flash memory story was cool
Great video! Will there be science fair kits in the gold store for us to get?
Love R51!
My favorite time of the week!!
How much did the earliest flash drive cost?
This was an incredible science live!
Amazing topic. I love this. Thank you Acellus.
The nano-tubes are cool.
I love science live!!
I liked learning about flash drives. My mom has some flash drives.
I thought that it was interesting that amplifiers are used in playing instruments.
Hydrogen cars sound so amazing!
I LOVE SCIENCELIVE
Hello Mr. Billings!
I love the idea of hydrogen cars!
dr billings is great
I liked when they talked about vacuum tube amplifier. and how they invented it.
YAY IT’S BACK!!!
The story about the flash memory and how they used new tech for it like USBs was super interesting to learn about!
I love the new science live part with the proteges.
I love science live so much!This video was very interesting.
Acellus World sounds so exciting!
This is my first time watching. I like it.
Hello from California!!
Chemistry in everything
Yes science Live is back!
So glad to have you guys back. We missed you! Also excited to learn about vacuum tubes
Awsome story on how the flash memory was made!!
This was so cool! Love science live 🙂
I have always wondered what a vacuum tube amplifier was. Now I know.
I love the David and Caleb part!
I like Tobias. i actually want him to be the whole thing.
I really liked the last part at Area 51.
That sunscreen sounds awesome! As a ginger, an all natural sunscreen sounds really cool.
i liked the david and calub part. it was very funny!
you should make a temporary class for the cups and rope.
such a great science Live!
what were all the batteries made out of?
where is the science fair located
the flashdrive part was cool
can i do the science fair if i dont live there?
Accellus is awesome
very nice episode. Thank you!!!!
I didn’t know dov Moran made the flash drive. Very cool!
can i be a vacuum tube amplifier??
This is awesome, I really like it. Hmm but I’m curious about when will this live science be over, I hope not! Gracias por el vídeo!
Im from kentucky,
Hello from Vietnam,
Thank you you guys for this wonderful opportunity to learn more about science in general.
The idea of the carbon tubes being turned into a wire for a space elevator is such a cool idea, but Would the amount of pressure that would be put on said space elevator be dangerous?
R51 is so hilarious
That is a neat material
Is a hydrogen car more environmentaly friendly than an electric car?
The science fair sounds fun.
Loved the new science live video can’t wait for the next video!
I liked how they made the USB.
How many people attend Acellus?
“How does a vacuum tube amplify a signal compared to a transistor?”
When do you think a hydrogen car will become standard, and actually change how people drive? I mean its been so long since the creation of vehicles and we’ve stayed with the same gas vehicle blueprint since forever. Electric cars are somewhat in the mix now but i feel gas cars still reign supreme over them in terms of popularity and how often they get bought. It just feels like its very hard to change peoples standard. Though it would still be amazing if it did happen.
This is my first time learning about carbon nano tubes!
Carbon Nanotubes will be awesome so my batteries don’t overheat.
Cool! I love science 🙂
R51 is my favorite!!
When is the next science fair?
Interesting! R 51 is funny as usual lol
The Prodigy’s were talking about radio transition waves and how you can send waves and how they can only go so long, but could you make a repeater to make the message go longer?
R. 51 is funny.
Science live is awesome
What is the world‘s biggest carbon nano tube? And where was it found?
Science is always the best!
I like how the flash drive was used
I would like to have a stronger battery.
I like how the science live explains the engineering behind things like the vacuum tube amplifier.
I like how science live explains the engineering behind things like the vacuum tube amplifier.
I like carbon atoms can be stronger that steel and it such a small size.
This live is so interesting! I love science live!
wow! Hydrogen cars are sooo cool!
There’s something about Tobias with the way he’s able to talk and engage with the audience more than the rest of the speakers in every Science Live. I feel like I learn more from him than from every single speaker in all of the episodes. Like, for example, I actually retain information about how Steve Jobs’s team working on the first iPhone invented a system that predicts the letters/words that you’re going to type to counteract how no one could type fast in a smooth and fluid way. Tobias will forever be the GOAT!! I truly hope he never leaves Science Live and Acellus as a whole. 💪🏼😎
It is nice to know that all the students are from all over the world
Hello from SC. I love watching your science videos.
I am excited for Acellus world.
I really enjoy these!!
Where is the science fair located? Not copying Briella literally just asking the same thing 🙂
Thank you for providing these episodes each week!
I love science live, science is my favorite subject.
Science is my favorite.
Love R-51!
i think its cool that you can talk through cups and string
I agree that honestly does lead to success. The truth will set you free!
I love science lives, I feel like I always learn something new.
love watching science live from florida!
Another great video, thank you so much for putting in so much effort!
Vacuum Amplifiers don’t change sound, they just make it louder (like my headphones )!
This episode was so cool, thanks for teaching us these topics!
Loved learning about vacuum tubes!!
Hey it’s Lexie from nb Canada
Wow! Hydrogen cars are very interesting.