Look Inside This Tube Amplifier!

[@MrCarlsonsLab]

To learn more about electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab

[@Haamedtm]

It would be nice if you do a project from scratch for educational purposes, any project like a power supply, audio etc...

[@W1RMD]

@@Haamedtm good idea!

[@andyhyde4711]

I have a golden db230a. Nice piece. All original. I refuse to touch it.... I use it daily. No hum. All original. I just unplug. At times I wonder if I shouldn't just box up nicely and seal it to preserve it.

[@alfa168fan2]

@@Haamedtm +1

[@maharajjinkb7824]

Excellent instructional videos. Mr. Carlson knows his stuff.

[@peep39]

These videos ARE making things a little bit better for me. Thanks for increasing your presence

[@jiveturkey9993]

The world needs you to have a store where people can walk in and buy all that cool stuff off of you.

[@benedictnothing]

Great video, as usual. Fascinates me how you can be so concise and coherent while explaining some pretty complicated stuff pretty much off-the-cuff. Heck of a talent.

[@MrCarlsonsLab]

Thanks for your kind comment Benedict!

[@maryrafuse2297]

You are the most brilliant of all teachers on KZbin. My husband and I are proud that you are Canadian. You represent our Country very well and your insight and creativity are above all the others. Stay safe in these COVID 19 times.

[@VitoVeccia]

Well I'm American, but I'm proud to support this channel. Canadian or not.

[@fredfeldmeier8228]

Indeed

[@VladimirPutin-p3t]

​@@VitoVecciaIM A AMERICAN AND I AM PROUD THAT PRESEDENT DONALD J TRUMP REPRESENTS ME AS MY LORD AND SAVIOR AND PRESEDENT OF AMERICA THE BIBLE INSTRUCTS US THAT WE SHAL WORSHIP NO ITHER GOD THEN PRESEDENT DONALD J TRUMP DO WORSHIPING A UTUBER IS A SIN

[@danev1969]

I took my first lesson in VT theory and amp electronics in High School back in 1958. I had then, and still have now, an almost insatiable curiosity. It would have been so much easier back then if I had a teacher with your deep knowledge and teaching skill. Thanks for giving us something different to watch (and learn) while stuck at home.

[@TheHermitHacker]

Thank you for keeping us busy watching!

[@philipblick8887]

You put in much time effort into all your videos sir. Here in New Zealand we are currently in total lockdown your videos help me to remain sane and calm. Thank you again kind sir!

[@MrCarlsonsLab]

Glad to help Phillip!

[@stevemckee5682]

Thank you for the extra videos, I always enjoy them.

[@MrCarlsonsLab]

You're very welcome Steve!

[@gheorghemoraru634]

AWSOME! GREAT JOB YOU'RE DOING! ROMANIAN ELECTRONICS HOBBYISTS THINK YOU'RE THE BEST IN THE INDUSTRY! THANKS A LOT!

[@granvillemeikle3894]

u r my teacher,u r so concise in ur delivery.

[@nevillegoddard4966]

@@granvillemmeikle3894 So r u lol!

[@victoryfirst2878]

So nice to see a real pristine USA made unit know for quality. Thanks for showing us the unit Mr. Carlson's Lab. Really enjoy your show. Keep it up and going.

[@PerspectiveEngineer]

Thanks Mr. Carlson

[@cgtower8860]

You are a saint Mr Carlson! Than you for keeping us entertained in the way you do. Stay safe yourself please!

[@MrCarlsonsLab]

Thanks CG!

[@chaddumas2499]

These videos make quarantine just a little more bearable. Thank you, Paul.

[@MrCarlsonsLab]

My pleasure!

[@theduckisok]

You are keeping me sane! Thanks Paul.

[@frankw.mclaughlin1938]

I would love to watch a restoration on both of them.

[@jp040759]

Thanx for the videos. Really helps time go by and not feels like it was NOT wasted time. Time well spent learning. THANX

[@Penfold8]

You should have a "This is my life" episode so we can learn a little about the man behind the vacuum tube!

[@waynethompson8416]

Now that is an EXCELLENT idea!!! EXCELLENT !!!!!!!!!!!!!!!!!!!!!

[@wadereynoldsgm]

+1

[@DarkFlamage]

I think that's a fab idea too!

[@kgsalvage6306]

I'm right there with you guys!

[@hyperchannel4048]

I am sure that the man behind the vacuum tube is also the man behind the soldering iron and the man behind the video editor screen and there must be a man behind the storage and the purchasing. And sometimes it looks like someone is behind the camera too. It takes a lot of extra time to create so perfect videos. He should better take some time to catch some sunlight.

[@michaelricketson1365]

Your posting of videos definitely helps to get us through these times! I always enjoy watching.

[@guitarmaniax]

My parents built their hi-fi component system in the 1950s, before I was born by a year or two. They used this amplifier or one very similar to it, along with a Sherwood FM tuner with a “magic eye” indicator tube, a Rek-O-Kut Rondine turntable with a 16” Audax tone arm and a GE cartridge, all encased in a cabinet they designed with record storage below. I still own this cabinet and all the components. Their Bogen used 6V6 power tubes but otherwise looks identical to this one. I especially liked the preset EQ control with settings for US 78, EU (European) 78, NAB, POP, RIAA, and Col-LP (Columbia). Obviously before LPs were all standardized to the RIAA Curve. The sound quality was superb and eventually I bought two more of these amps, hoping to have a couple of them restored to use in a stereo rig (someday, when I am a very old man, the way things are going). I wish I knew enough about electronics to do this myself, but looking at the interior components I find it rather intimidating. Thank you for your thorough delve into the guts of this wonderful amp.

[@chazdog789]

Thank you so much for what you do Paul...

[@alfa168fan2]

I had this DB130 for years. Love to restore it someday..

[@suicida2009]

Thank you for sharing your insight on how to troubleshoot and diagnose this sound amplifier, waiting for restoring process video, be safe.

[@i82996]

Thanks for taking the time on the theory. I discovered from your video why the screens on the 6K6 output tubes of my Hallicrafters SX-71 and SX-100 get voltage off the voltage regulator tubes. Be safe. Albert

[@ssn90]

Even I will be joining patreon... My community has a lot of repairable electronic junk which I hope in a few years I can prevent from reaching the land fill thanks to greats like you. You are very inspiring & a thorough professional!

[@harrystevens3885]

Brilliant, when the bottom came off I wondered if a nice jigsaw puzzle could be made from a high quality picture of the underside......Thanks for the extra videos it's much appreciated and some amazing restorations to be done....:)

[@smjones4238]

Years ago (70s-80s) I replaced many Bogen tube type units. Mostly commercial audio amps with 70.7v and 25v speaker line outputs. Most of the customers liked them as they lasted a long time and wanted Bogens as the replacement amps. I had a shop that took all of the bad units that I removed and used them for parts if they couldn't easily repair them. I got many of my spares from this shop. There also were a few commercial Harmon/Kardon units that I replaced. Nearly all of what I worked on at that time were Mono as they were mostly PA/background music systems. Another great video Sir! Michael in Colorado.

[@jlucasound]

Oh my goodness. That is Gorgeous!!

[@Geoduck.]

I've owned and basic rebuilt several lat 50's Bogen amps. Amazing build quality and the simple DB110 is one of the very best vintage amps I've owned.

[@atompunk5575]

This is cool, why is old technology so interesting and unique to its time?

[@kgsalvage6306]

I just love that design. I love building tube amps and I'm always looking for a new fairly simple designs to try out. I wouldn't say It's the simplest, but I would really like to hear how they sound. Definitely continue on with your restore!

[@GeorgeZ213]

Just saw a vid of you from 9y ago. Your looks, attitufe and communication abilities have not changed one bit.

[@Dixielsncjd]

What a crazy scientist. I love this! Super awesome to find these niche channels. Keep up the good work!

[@hakemon]

These video's are making it easier being at home. Thank you!

[@jimgiordano8218]

I use Bogen amp's in commercial applications for paging and sound. They are extremely reliable and have great sound. Nothing beats the sound from a tube amp though, I find they have a wider range and much fuller quality, especially with vinyl records. I can't wait for this restoration. BTW, that amp looks like you just unboxed it from the factory, super clean.

[@EsotericArctos]

I really look forward to seeing this restoration. The amp looks in beautiful condition. It is great that the seem to give a schematic of what is in the little "Printed Circuits" as well. That would make troubleshooting a lot easier.

[@BruceNitroxpro]

Brendan White , He would then explain the ones which look inscrutable! LOL

[@jamesvw769]

Carlson a million times Thank You.

[@MrCarlsonsLab]

You're welcome James!

[@djfrank59]

Definitely repair/restore both amplifiers. :)

[@fichambawelby2632]

Again, and specially now, thanks for your excellent job, Paul. It is the best thing somebody like me can do this days: looking and listen to you. I hope all is well for you there, and I send you all my best wishes from here. Is the least that you deserve.

[@frankowalker4662]

That Bogen DB130 is so well laid out on top, and looks in mint condition. Can't wait to hear it after the re-cap.

[@donaldpassantino2293]

I strongly recommend replacing the 6AV5 output tubes (rated 550 volts max plate voltage and 11 watts) with 6FW5 tubes (rated 770 volts max and 18 watts dissipation) for reliability. No circuit changes needed. These sweep tubes have a 175 volt maximum screen voltage rating so the voltage regulator is needed. Sweep tubes have huge cathodes for high peak currents and linearity. Speech and music peaks are ten times the average power so these amplifiers have tremendous headroom. I have a Bogen LX60 60 watt high fidelity public-address amp, based on this circuit. I changed the four 6AV5 to 6FW5 twenty years ago and it can peel the paint off the auditorium walls without clipping. I also have two DB130 amplifiers. All three have huge output transformers for great bass response. The Bogen manual explains how to adjust all the chassis controls. Variable damping was supposed to increase the damping factor for tight bass, if you set it for minimum damping it will sound like a boomy old 1950's Jukebox. (Note my 1960? LX60 amplifier uses newly-available 5AR4/GZ34 rectifiers which also give higher plate voltage and delayed high voltage at warm-up)

[@MrCarlsonsLab]

Thanks for taking the time to write Donald!

[@leukostad1592]

The 6AV5, one of my favourite tubes... the type I stocked the most. I like this amplifier, I suppose it sounds neat.

[@dbeaumontresident847]

I love these videos, thanks Mr. Carlson! Be safe during these times.

[@JSGregg]

Beautiful amplifier! I would love to see you do a video, or a series of videos, walking us through the design, development, and demonstration of your own audio amplifier or receiver from scratch. That would be amazing!

[@cristianchisbora8289]

Mr. Carlson, your videos are always inspiring, but i think we all want to see some restorations!

[@tomhood8897]

My prayers have been answered!!!

[@gideonwackers7693]

Yes your videos are helping with the lockdown!

[@mikepelletier1399]

Thank you paul!!!!

[@MrCarlsonsLab]

My pleasure!!

[@More_Row]

Thank you for the vaccines against cabin fever Mr. Carlson.

[@mkshffr4936]

Would love to see some work with unusual tubes such as space charge and pencil tubes.

[@glennsprigg2378]

Fantastic as always! Re: your older post on the... "Electronic Restoration- The Supreme Vedolyzer! 1939 (Part 1)", I found the correct schematic that you had to work out yourself. I just left details on that post. You're the best, Paul !!

[@MrCarlsonsLab]

Thanks Glenn. I have the correct schematic, and I was the one that submitted it to the Supreme site to share with others.

[@glennsprigg2378]

@@MrCarlsonsLab Well that makes more sense now!! You are the best!! :-)

[@hi-friaudioman]

Your videos are great Mr Carlson! I love the content you've been putting out lately. Thanks for keeping my brain in shape.

[@turbochardged]

Thank you for so many great videos during this time. I'm already on patreon.

[@MWSRD]

No Doubt you are indeed a genius, I love your videos and long may they continue many thanks from Scotland.

[@scottlundy257]

As Mr Pete says Clear as Mud . There is not a better teacher than Mr Carlson Thats over my Head I got lost after the power cord .

[@jamescameron5472]

Thank you sir...just the tonic at this trying time...

[@zuke-ci4vd]

Looking forward to the restoration of this piece! Should the second amplifier have the same issues, I don't think it would be necessary to film that work. But, if you find something unusually wrong with that one, maybe just film that part of the repair. I have a rudimentary knowledge of electronics, but find your explanations of what you are doing, and how to approach a repair clear and entertaining. I especially like your schematics overviews, I have learned so much from your videos from that alone! Thank you for all the hard work and dedication you put into your channel!

[@mkshffr4936]

Nice bit of kit. Love fire bottles.

[@GraemePayne1967Marine]

Every time I look at one of your videos it triggers a trip down memory lane. Sometimes the equipment you are explaining or working on, with this episode it was back to the vacuum tube block of my early technical education. And every time I see your array of test equipment I realize that in my career I have used-repaired-calibrated just about everything I see. The first time you mentioned the B+ line reminded me of the first time I was given a newly introduced digital multimeter to use. (A well-known brand which I won't mention here.) I was working on a item vacuum tube equipment at the time (don't remember what). When I went to measure the B+ with that new digital meter, it displayed an overload indication. That meter only went up to 200V! My comment to my boss about the meter was "what the **** good is this thing if I can't measure B+ with it???"

[@planetwisconsin9901]

Thoroughly enjoying the videos sir! Thank you!

[@jussikuusela7345]

Although I'm not stuck at home, I've been laid off work and likely will be for another month or so. I have very little social interaction outside my immediate family anyway. Your videos are a great pastime and although I studied electronics over twenty years ago, there's almost always something new. This is a great channel, and I even took the entry level Patreon subscription.

[@hespanola745]

HEY THANKS.I AM LISTENING TO YOU VIA TWO BOGEN HT-125'S INTO TWO REALISTIC TOWERS 12 INCH WOOFERS THREE WAYS AND IT SOUNDS PRETTY GOOD!

[@hespanola745]

@@anonymic79 ELECTRONICS HAS BEEN MY HOBBY MY ENTIRE LIFE!

[@jgrimsley2000]

I used one of these amp as my guitar amp when I was a teen in the 70s. It wasn't antique then....my dad picked up at a garage with a matching tuner, but he only wanted the tuner. It was a great sounding amplifier.

[@MrCarlsonsLab]

I have the tuner as well, I may do a video on it too.

[@Grumpy_Granddad]

Mr Carlson's Lab yes please

[@brodyu]

@@MrCarlsonsLab I have the db130 and matching tuner, and would absolutely love to see the restoration of both. I'll build along! I can't believe this is actually happening! Love your channel btw!!!

[@mickward2775]

Thank you Mr. Carlson for sharing your time and knowledge with us Fix them both because as sure as you don't it will be different faults on both of them

[@leonvanderlinde5580]

I love the Marconi 2955 in the background.

[@tedvanmatje]

Wow...that's a nice looking amp! That voltage control circuit is new to me, so I'll be downloading the service documentation methinks. Thanks for churning out the recent videos Mr C. It's whats needed in these times of forced procrastination. I've lost count how many times I've vowed to join your patrion over the years. Once the financial situation is sorted, it will happen, lol Wishing you all good health!

[@petaks01]

Thanks for the very nice look inside, always a pleasure to see a close to virgin amp.

[@brianfitzgerald6142]

Many thanks for the video, Paul. You are right... you are helping by posting.

[@slabrankle9588]

Thanks for the increased content. I really look forward to new videos from you, as do all of your subscribers no doubt.

[@dhpbear2]

I love the little touches in this amp. It reminds me my Dad's Bell that he bought around 1952! Same color chassis, but taller Also, the 'bells' of the transformers are mounted *under* the chassis! :)

[@larryowens2859]

Love your videos, wish you were local I would love to visit your shop, thanks so much Larry Owens Calif.

[@moi01887]

OMG I had one of those when I was a kid! I got it at a yard sale or something, it had an output transformer or bias issue or something and the plates on the output tubes would glow red as soon as it warmed up. I didn't really need an amp but liked all its EQ and tone-control features so I snipped a few wires in the output stage and turned it into a preamp.

[@jamesvandamme7786]

You probably could have repaired it with a couple capacitors.

[@PhG1961]

Oh, believe me, you sure entertain me ! Great projects !

[@Philip-KA4KOE]

I am a double E PE, but my expertise is in construction documents for buildings, etc. I didn't really LEARN electronics till I started repairing my own broken radios, transmitters. Nothing beats hands on work. Excellent vids Paul. Look up "Bauer Power" to see my restoration of a 707 transmitter here on KZbin.

[@MrCarlsonsLab]

Thanks for sharing!

[@jameskirk5283]

I have been enjoying your electronic videos. I've been a tech in the tube erea, and love being brought up to date on solid state technology. THANK YOU !

[@nevillegoddard4966]

Very nice amp! The voltage regulator section is fascinating. Be interesting to see the differences in the problems these 2 amps may have.

[@victorbregeon594]

Sometimes ago, you talked about a giant rca transmitter, it would be interesting to see that restoration ( maybe it's on patreon) Thank you for all your vids Paul !

[@lawrencegsobczak2077]

I vote for showing both restorations. Im interested in seeing if they have different repair issues.

[@RelabTV]

I love your videos since you managed to break down the schematic that looked like a maze to me to small bits that intuitively make sense. I thought i will never be able to undertand it when i looked at it. Great work! :-)

[@johnharrison325]

Hi Paul, I just came across 5 Bogen PA amps ranging in output from 10W to 70W and looking to restore and re-purpose them. So I found the series you are doing with the DB 130 very timely and would like to see you restore both amps. As others have commented...maybe a matched set! Am also enjoying the Urban amp rebuild and think you have done a masterful job in the design to show off the tubes and fit everything into a very small footprint even with the point-to-point wiring. Yes there is a positive side to all the time we have available right now.

[@richardlamoreaux8979]

Could you talk about the damping factor adjustment, which uses positive current feedback from the speaker to bump up the low frequency response.

[@dhpbear2]

Paul. Thanks for your recently stepped-up rate of video releases! Cheers!

[@rossdtool]

That's a really nice looking amp.👌👍

[@tadonplane8265]

My dad had a hi-fi with this exact Bogen amp when I was a kid, but he lost all the components except the amp in a move. When I was a teen in the 70s we helped a coworker of dad’s move and he gave us his Bogen amp, again, exactly like this. We used one amp to drive the left channel and the other drive the right using a stereo turntable and a Radio Shack FM tuner as sources. We built the speaker cabinets using 12” guitar speakers and horn tweeters. We ended up with the baddest a$$ stereo in the neighborhood! Everyone, teens and parents alike, came to our house to hear it!

[@jayb9687]

I don't know how I found you but I'm glad I did. :)

[@scottferguson1932]

Thank you for doing so much work to keep me entertained! :-)

[@nfijef]

Great stuff Mr. C thank you!

[@Ale.K7]

Would love to watch them both being restored!

[@bobsykes]

I appreciate every content creator making interesting and educational videos during these times. Thank you!

[@richc47us]

thanks for your thoughts and lots of good stuff! Never thought Bogen was a hifi quality amp

[@mkshffr4936]

Back in the day they made quite a bit of hi-fi quality stuff.

[@delroylewis542]

i am the silent listener viewer from london love your video,s

[@PicaDelphon]

Bogen AMP, Nice unit, back in the Day when Everything was Made in NJ..hehe..Great Unit..

[@MC-ph7gr]

Thx for the video. I wish there was a sound test at the end

[@I-T-S-M-E]

Appreciate these videos Mr Carlson 👍

[@Mr549er]

awesome what you did with the crate amp love it :-)

[@td3993]

I have the complimentary tuner for this. Still works. All original except neon lamp.

[@estebanwedontneednostinkin9969]

Thanks😷

[@davidwalle5025]

Good video mr. C. Restore both amps.

[@richc47us]

I ran across Bogen amps in the '60s that werre used mainly for PA work...interesting vid and thanks again.