600 Volt Tube Op Amp! Lets Power It Up. 

At RCA labs I was the guy who tested the 12AX7 tube and matched them up using a Tektronix scope curve tracer. I built a chassis to pre heat 100 tubes at a time fir the 100 hour burn in time . All the data was recorded by hand and cataloged in bank of file cabinets. It might appear you the reader as a dull and monotone nous job, but I loved every minute of everyday. The money was very good and I got to work with real gentlemen like Mr. Carlson. Staying late at night working overtime was a joy . I learned so much. Then it all ended with my induction into the United States Army. Fortunately fir me the Army realized my skills and trained me to repair radio equipment. Two years later when I returned hime , my old job was available to me, but now the technology had changed so much and OP amps were now solid state bricks. Testing and setup the was done by machine. I used my Army experience and went back to RCA training as a Radio / TV technician. Color TV service was a good job in the mid sixties, however I did not like doing in home repairs. By 1970 I earned my way into the shop and later on into the research lab. Over my 40 year experience i had to learn so much as technology never stood still. Here I am at 80 watching Mr. Carlson’s refresher course videos of my life. I am proud and very hard to have chosen electronics as my lives work and hobby. For all of you out there, stick too it and stay with it. Electronics is hard but interesting work that nerds do. Wear that title proudly. with

I used an analog computer in the late 60's. It did differential equations in real time, where a digital computer would take all night to run. You could simulate a car suspension, for instance. It used op amps like these. Your lab looks like mine 30 years ago.

On behalf of the people of youtube, we appreciate the honesty, and also the time involved in setting the camera up 600 freakin' times........

Today’s my birthday I told everybody to hold on one more hour to put off dinner and watching a video on vacuum tube opamps. I Learned a little more today👍

Mr Carlson is now officially the guy I would most like to meet ever!

Several decades ago I bought one of those NOS. I had a boss who had a Phd in electronics who got his degree in the 50's tube era. We mounted a socket on a fancy wooden base and gave it to him for his birthday. He was ecstatic to get it and often chided us gently about our solid state devices.

Digikey only discovered nanofarads a couple of years ago...

Fantastic, I remember these from the late 50s and analog computers (I'm 81). I always thought they were impractical until the 741 showed up in the mid 60s.

My dad was an electronics engineer. He owned and operated Wes's TV repair in Banning California. He closed his shop in i981 and passed away in 1983. He was an ' old school' electrician. When the age of integrated electronics came to rise, he could not keep up. His eyes were failing him as do most older people. He taught me a lot about electronics. Especially the old tube based stuff. I never really got into electronics. I haven't even thought about it for more than thirty years. OK, so. Just out of boredom or maybe curiocity, I decided to watch this channel. It truly surprised me that I completely understand everything that was talked about here. You would think that after all these years, I would forget all that stuff. Get into the modern electronics and I am as dumb as a rock.

Never would have thought I could stay interested in 44 straight minutes about a tube op-amp. Well done! Impressed by your attitude to safety also; so important when disseminating knowledge. Double thumbs up!

Great Video. I used tube opamps during my Melbourne university electronic degree back in 1960's. Our analog computer had 100 channels which allowed us to model quite complex systems. The computer (MUDPAC) remained in service until 1970 when digital computers were cheaper. Analog was still used for real time emulation in rocketry because analog computers could integrate/differentiate much faster than digital computers. They were also much better for non-linear systems because of their high compliance (+/-100V). Sadly by 1980 all benefits had disappeared and IC OpAmps and digital computers completely replaced tube opamps.

Today is our 36th wedding anniversary, and I am watching Mr. Caslon's Lab. Fascinating!Nice op amp Paul. Thanks for sharing.

Nice to see this very clear video, and nice to see tube op amps... I wrote my master's thesis building a D/A and A/D subsystem between an analog computer (using these) and a PDP-11/45. I've been doing analog and digital hardware design, plus software design, ever since.

"Leave the scary stuff to me." Yes, sir, I will! High voltage, open terminals... I'll stay well clear! :) Very interesting to watch, though! Thanks, Mr. Carlson!

Way back when (1964), while my friends were into Ham radio, I built an analog computer, based on modules built into Vector aluminum cases. A typical Op Amp module was put together using one 6U8 and two 6AU6 tubes and the supply voltage was +-300V. Still have one right in front of me as we speak. The plug-in module used an eleven pin octal socket. Fun stuff! Also, nF was not an unfamiliar way to express capacitance at the time. Enjoy your videos, for sure.

I really like watching your videos. There are times that I smile. I am a retired Broadcast Engineer. I regularly worked on transmitters that had 10 KV on the plate that could deliver up to 5 A. So you say this is dangerous and I smile.

This is a blast from the past for me. I worked at Red Johnson Electronics 1966-68, at the counter, a surplus store on El Camino near Stanford where I went to school. One day I came in and one of the boss's friends was sitting with a large pile of these - he'd cornered the market for these devices at the same time that the first IC devices became available, and the only value they now had was for the tubes in the units so he had thousands he was pulling the tubes out of in order to sell the tubes as a single lot.

Just an amazing video describing an ancient artifact. Suddenly i want to implement one and test all its possible configurations. Thanks again for the quality content here and on Patreon.

The battery demonstration really helped me understand what was going on with the +/- 300V and 600V total, i initially didn't get it, thanks for these really great videos

Why am i still watching mr carlson at 4.30am ? Wife got bored at 10pm and went to sleep i am in trouble in the morning !

Awesome! I found one of these in MIT's ham radio room. It was this same model I think. Now I want to build something with it after watching this video!

A 43 minutes video that looked like a 4 minutes video. That proves how well done and entertaining this video has been for me.

I remember the LM341 op amp. It was the standard transistorized op-amp on a chip that came out in the 1970s. But, I LOVE this tube op-amp. And I love that you found it and showed it to us Paul !

Paul, without you and your Channel, I'd have no chance to see such beautiful devices like this extraterrestrial looking op Amp ;) You are the only person I know, who can play the famous "Crocodile Dundee - That's not a knife" scene with opAmps :D BTW: Congrats to your TekScope which looks awesome too and many thanks for sharing such great content!

Started to get hives when you showed the first picture! When I was in the Navy my first duty station had me working on a piece of gear that used , literally, over 500 of these things in a trainer that simulated 16 aircraft, 9 destroyers and 1 aircraft carrier. Each vehicle had it;s own operator and the device was housed around the perimeter of the base theater. During the winter months it was the warmest place on base! LOL

Again 5 days in "good" school or 43 min with Carlson...

The most scary capacitors that I worked with were 100 μF at 8.6 kV, used to power an x-ray machine. One of the safety compliance tests was to demonstrate the mechanism to directly short the cap if the cabinet was opened improperly. The first test vaporized the hinge on the shorting bar. It sounded like about six double-barrel 12 gauge shotguns being fired at once. Needless to say, a much larger hinge was designed and tested.

This is amazing, seeing this technology working. And it's accurate, as well. Thanks for sharing it! That 155V P-P output is also very impressive!

Takes me back to my "Electronics in the Laboratory" course in school. Our professor had used quite a few Philbrick op amps as a student. He brought in a Philbrick brochure and manual for us to read. We were all happy that the 741 had taken its place.

I've been watching a couple years now and I really want to thank Mr. Carlson because you keep giving me the motivation to work on my own projects :)

It is 3am, video about old opamp. Brain: you are not getting any sleep tonight

OMG this op amp is amazing :o, thanks Paul for the best electronics classes I've ever had, success professor!

I have been waiting for this for some time! This should be great!

It's obvious that you had a lot of fun making this video. It was quite entertaining to watch. Thanks for sharing this old tube op amp with us!

Very good video. Back in the tube days vehicles were making the transition from 6 volt to 12 volt electrical systems. So a center tapped heater would allow the designer to build a radio that could operate on either system.

Thanks Paul, I enjoy all of your videos.

Thank you for making my Lunch hour at work the best. Working nights just got better!

your demonstration of negative voltage using 9v batteries was incredibly comprehensive. i have been trying to wrap my head around it for awhile now. thanks!

You did it again, I get ancient computers now😃 You are really good at explaining things, while I relax I learn- If school were like this I'd have loved it. Thank You, I am so glad I stumbled upon Your channel.

I restored a Dymec (HP) 2401A hybrid tube/transistor 5 digit systems multimeter a number of years ago that was made in 1962. At the front of the input is a Philbrick Research supplied tube type op-amp printed circuit board. An interesting piece with very thick, gold plated traces. It inspired me at the time to read about GAP/R, and that was as interesting as the Dymec meter itself. Thanks for this segment.

Before watching this video I was having just theory knowledge on opamps and analog computers and I have to memorize most of it🤯, after 43 mins I can understand the whole book which I read during my engineering. Thank you very much.

I am just stunned with your level of knowledge. Amazing and thanks! I know next to nothing about electronics, but I’m enjoying learning.

As I went to college for electrical engineering I never even knew a tube op amp existed. How cool. Thanks. I was interested in analog computers but they were solid state.

Awesome video! Thanks for taking the time to show us this, now that is able to multiply it would be interesting to see some of its other functions.

I enjoyed this lesson so much it's been reminded 3 times. Keep up these invaluable and very particular lessons !

Been sitting around for a month with a broken leg, nothing to do, waiting for a video, I was getting ready to cut my wrist ! Thank you Mr. Paul!!

Great Video, I remember using these analog tube amps back in the 60's and 70's.

Incredible video. Never seen a Vacuum Tube OP AMP. Been in audio for years. This was fun. Great video Mr. Carlson.

Don't know how you find all this neat stuff, and in excellent condition. Great video.

Bob Pease started his career at Philbrick and wrote some of his Pease Porridge columns plus some articles in at least two compendium books about his experiences there. We never had any of these Philbrick tube op-amps. They were way expensive for our control systems. We built our own with 2N930 transistors that we mounted as pairs in aluminum blocks to keep the temperature matched. At one time we had stability problems on a purchased production line that used tube amplifiers, thyratron tubes and finally a Ward Leonard generator set. We improved their tube op amp circuits as a quick fix, but then we replaced the controls with our own op-amp and SCR system. In those days, the SCRs were new and the best ones we could get were 2N688 (later on 2N692 became our standard SCR). Our op-amp had a maximum gain of about 3,000 and when some commercial modules became available (from Fairchild as well as from Burr-Brown and naturally from Philbrick) that offered gains over 20,000, we occasionally used those. The next attempt was to use Fairchild 702 IC, but its unbalanced voltage swing was no good. Quickly, though, there came the 709 that was good enough to replace our own amplifiers as well as the modules. And then the godsend 741 arrived.

Great video and as always I learn something, keep it up Mr Carlson. Thanks for the best on RU-vid

Yes, a tube op-amp was very interesting. It worked amazingly well and what a fantastic output range for an op-amp.

Nice video Paul, I guess the Op Amp won the video contest. Hope to see the others soon. Thanks again for another great video.

The time that the internal circuits were openly shared with the user. Great job!

I love this. Gunna build one thanks !!

Never saw an tube opamp before! Really enjoyed it! Thanks!!! 😊

Good stuff, that tube op amp is a remarkable find. The math lessons reminded me of broadcast engineering class back in the early 80s. Thanks for the awesome project!

i love how you push things/electrons to the limit, and describe in detail what is going on !! you are equal to a college professor,.,. i love it

I'm speechless... Excellent lesson! 🤗 🤗 I've learned so much about this tube op amp!! 🤗 🤗 🤗

That was a blast from my past. Well done.

My kinda cool! Mr. Carlson rocks

You're great Mr. Carlson! It's always a learning experience.

As ever, an excellent, clear and clean explanation of a non very usual device (I mean, a tube opamp, not a solid state one). Thanks a lot for your great videos.

I actually have very little interest in vaccum tubes, I am a solid state guy, but you make such great videos with such detailed explanations, I am addicted!

Great demonstration of the op amp. happy to see tubes involved. 73, ad0am

The two battery - + power supply explanation was excellent.

I have never seen or heard of an op amp so I learned something new today

This video answers or illustrates a great deal of what Paul is always mentioning about the nature of capacitors. The risky nature that is. This is a great video. Absorption.

YABBA DABBA DOOO! Another AWSOME video. Totally worth the wait!

Thank you for the simple explanation of negative voltage.

Great learning experience. Thanks for the feedback loop on negative vs. positive.

Great job Paul! This is a great way to demonstrate the early COMPUTOR :)

Your videos are great. Learned a lot from watching them. I have been messing with electronics since I was 2. I never messed with anything that had tubes. I love watching them glow. I have started my journey into tubes. I got 6 magic eye kits and wanna connect to an Arduino and make a spectrum analyzer with them. I already have 1 on each stereo speaker for level indicators. Keep up the great work Mr. Carlson.

Wow nearly 50 views in 1 minute. Proof that people love your videos.

Just discovered your vids...GREAT work. I like how you have the balls and confidence in your knowledge to actually franken-build these little experiments...not only talk talk talk like most other channels. Build shit that CAN kill you...THAT is the ticket!

Thanks for the great video and helping me to better understand my old Heathkit EC1! I really miss it😢 Keep up the excellent work!

Another informative video. One other thing I learned, in all my years in electronics (60 + years), I always thought that the writing on the tube designated the filament voltage, the engineers initials that developed the tube, and of course, the number of elements. Oh well, learn something everyday.

I would have not even believed there was such a thing. Really cool.

Awesome video mr Carlson big thumbs up 👍

Thanks for warning "normal" people about the higher level voltage in tube systems. Mr. Carlson is correct. THESE VOLTAGES MAY KILL YOU. I even give 250 volts and up a very high level of respect, even though I have been hit by 2nd anode wire on a 25" CRT and DIDN'T DIE!!! Mr. Carlson, thanks for having this material available for us. We need to get into a great conversation about many things involving electronics and flow paths. We would both walk away with advanced enlightenment. Consider this someday. You won't regret.

Very cool demonstration. Didn't know about the derivation of the 12.6 CT filament. Educational.

What a bunch of awesome test equipment. Wow!

You are such a good teacher

Great video. I’ve been playing around with “solid state” analog computers to learn more about op amps. I’ve got a few working Comdyna GP-6 computers, and a whole stack of Heathkit EC-1s in various conditions, but mostly working. I find the subject fascinating. Most of the early missile guidance work was done with analog computers. I’ve picked up a couple of Philbrick P2 transistor op amps, but I haven’t had a chance to try them out. That op amp was in beautiful shape. I didn’t realize they used 12AX7s. I saw the base on eBay a few times, but passed it up because I thought it would be hard to find tubes for it. If anyone is interested in learning about op amps, the old Philbrick applications manual is a really interesting read. The pdf is available on the Analog Devices website. Thanks for your great work Mr. Carlson!

The first time I used opamps was in the 60s at a NASA ground station. They were plastic blocks about 1 inch across and made by Burr Brown.

Mr. C Nice work, thanks for sharing

That was really great - it seems you had fun too!

That is wild!! What a find! Thanks for sharing.

Don't forget mmf (micro micro Farad). That was also a very popular unit of measure for caps way back when.

In a similar vein I remember "FETtrons" - solid state direct replacments for valves (tubes). The FET circuitry mimicked the performance of a particular valve and could literally be plugged into the existing valve socket,

We used literally scores of K2W's in the Navy's X14A6 Antisubmarine Warfare Tactical Simulator at the Navy Operating Base (NOB) in Norfolk during the late 1960's. They were driven by a digital time base established with a huge magnetic reed switch column that was a mechanical precursor to the soon-to-be all solid-state digital signal generator.

Your lab arouses me in all the possible ways

Truly a piece of history. I used to work there.

I did enjoy this video Paul.. Thanks for this sharing!

Nice Work Mr. C thanks for sharing

Wow - I actually recognized that op amp as a being from George Philbrick Research - it was used way back for Analog Computers - fascinating find and video! Only seen pictures of it though up until now - great work!

Your videos are incredibly interesting and when you work with tubes I'm remembering my old Telefunken Bw TV where one time I replaced a tube.... just saw the only tube not lighting up 😊

the high speed computer used by the British in world war 2 to decode the ultra secret enigma german code. used a room full of vacuum tubes. it was digital flip flops. this Analog Op Amp is interesting. must have been fun keeping those things calibrated.

Thank you very much for uploading that video I enjoyed it immensely I look forward to all your videos keep it up love your stuff