REPAIRING A SMALL TUBE AMP 

Not only is this guy an absolute genius, but he's also one of the most entertaining personalities on the web! We have more than 150 channels available on our cable TV, but I'd rather watch this guy any day. Thanks, Ron !!

Logic would dictate Glasslinger to be categorized as a national treasure.

6:47 Who needs Netflix when Ron is in full flow! Great stuff, thanks so much for taking the time to make these videos

I like it when you are in teacher mode in your videos. But its always nice to have new videos from you. Its going to with Ron. Thanks for sharing your knowledge with us.

Thank you again & again you have no idea how much we enjoy your videos and your Beautiful ways to approach toward the problems. 73 My Friend Malek KI7DYM

Great to see you back again! These videos are pure excellence, and you are greatly appreciated!!!

I know that Grommes Little Jewel 10 watt amplifier personally. It was assembled in 1950 by my 14-year-old brother. It worked very nicely for a number of years. I have no idea who did the "hack" but I'm very sure that it was not done by my brother who was a fanatical perfectionist. Thanks so much for bringing it back to life, harmonics and all!

Ron, you are the everything-teacher I never knew I always wished I had.

The instruction and knowledge you share in your videos is golden, thank you for so many ah ha! moments, you are a wonderful source of inspiration and entertainment for us aspiring repair techs

Am always happy when I see you have released a new Video ,Thanks Ron I truly appreciate your time and skill you teach and show the world these fantastic vintage radios.

Thanks for the tutorial on the spectrum analyzer, Ron. Loved the comment on replacing 80 capacitors in a tv set quickly to make a living.

Hahaha, man! I´ve never enjoyed so much a tube repair video like this one! Your laugh and your sense of teaching is awesome. Thanks and cheers from Argentina!

Love your cycle controlled electronic fuse box!!! Cup of cherries this time.

Your spectrum analyzer was indicting an overload when you saw the high distortion. There is a high probability that was the cause of your high distortion readings.

Hey, Ron. I just found your videos and an enjoying them. I worked in a TV repair shop (remember them?) during college. I restore radios as a hobby for the last 30 years. We're a dying breed... And brake cleaner is a new one to me

I searched for years for a Triplett 630 Anyways, finally got my used meter in the mail the other day. Everything Works ! I am thrilled..was going to go for a Simpson 260, but glasslinger changed my mind.

Stuck in quarantine, this site is a lifesaver. How many skills can one become expert in?

With 6v6gt tubes that's about a 10-15 watt amplifier. Probably between class A and full AB1, so maybe 50% efficiency, 30 watts. Add 20 watts for filaments, that's 50 watts total. Transfromers should be at least 90% efficient, so a 50 watt transformer should lose about 5 watts. I'd say that 5 watts in the transformer is OK, but at the high end of what I'd expect. As Shango66 has often demonstrated, you CAN often 'repair' noisy pots by cleaning them with de-oxide. Always good to try anyway, as it's easier to clean them than replace them. Linear pots are easier to diagnose with a meter than log pots. Also many digital meters have an 'analog' bar graph for this purpose! At least my fluke does. The reduction in size of modern capacitors reminds me of a scene from the movie 'This Island Earth'. Put the ohmeter on the voice coil!!

Hello young man. I have really enjoyed this video. I think you and I are pretty close in age. I have not had a lot of experience in audio equipment. My field has been in rf but our old principles are the same. These new techs have really missed out on using the old test gear. I loved watching you use that old equipment that some you probably built yourself. Glad to see you put in the notice about using break clean and getting it on the plastic dials. I learned this the hard way onsome old transmitters that parts are hard to find. Keep it up as long as you can. As I aged my hands shake uncontrollably and I have retired. I miss it so bad. God Bless you.

Good advices on soldering old stuff at 19:30 ! Not wasting time with wrapping wire before soldering, a small wire hook is sufficient! Please continue your practical video collection. I admire your deep experience and insight in glasstechnology , electron devices and restoring old gear. Thank you!

Brilliant Work Earthling Bless Up

That was a fun video, Ron, especially when you managed to pop that speaker..he-he. That event was water off a duck's back to you...just pop in to the attic and find another speaker, "No problem"...The rest of us here watching would have cursed this event and slung that speaker across the lab in annoyance and frustration, but not you, Ron, he-he.

blown away by the depth of your knowledge

You’re a genius. I’m an EE myself, and you are a master of many trades. Glad your video showed up in my feed, and subscribed. Keep the videos coming.

I like watching someone with experience and a Weller Gun. Nice job.

very interesting, especially the distortion measurement part... Good Job, as always.

I converted almost the exact same amp to a guitar amp on my channel. As a guitarist, we love the distortion. This little amp makes a great guitar amp. That's likely why the RIAA circuitry was ripped out of yours originally.

Always interesting to see your approach and methods. Nice work as usual.

Why I am watching this? Why this was recommend to me? I don't even know what this guy is doing on this video 10/10 keep going man, you doing great

Thanks Ron for another great video! Please keep them coming, particularly the glass blowing videos!

Your electronic wizardry is astonishing to watch.

I find pre PCB electronics absolutely fascinating. Keep the videos coming Ron.

Just found your channel.. I love old electronics and am getting back into this stuff.

Interesting as always. I was wondering if you could try building a magic eye tube sometime.

I remember Quietrol. That stuff was (allegedly) mainly carbon tetrachloride (early dry-cleaning solvent) with a dash of light oil, dye (it was red, like cranberry juice) and maybe a fragrance, too. Sure worked a treat.

4:01 I like how the leak detector has an analog meter, LED read out, and an LCD read out . :)

Nice work Ron. Another good vid.

"Had another one at the attic" ha, that was a masterpiece! To think that it was the speaker that was causing problems... I really enjoyed this restoration. Truth be told, the status quo ante stroke me as really modern and far from original. As if someone's been there, maybe even in this century.

Love the video. Much appreciated. Why do I imagine that the attic looks like the government warehouse in the Indiana Jones movies?

I had one of these Grommes amps, and a Pilot tuner, sitting atop the fridge in a house I had rented with a group of friends. Sounded good on FM through a Lafayette speaker, and occasionally we'd play guitar through it (lots of distortion). This was back in the late 70s.....

Very good video. This remembers me of my old amp. Many years ago I have bought an used tube amp, it was 100W, and made really clean sound. But I have never take a real look on the solderings. I should have done that because it blows up the output transformer as a bad soldering give up after some time and full current goes through (pentode..) and even worse, someone before me had increased the fuse amp ratings... So bad! So my advice, take a look at all solderings carefully before switch on any amp.

Just found your channel, love these videos! Keep them coming :D

This is a very good video, the suspense never ends! Very educational and enjoyable. You are awesome. By the way I'm only 3/4 through it. It must be hard repairing a kit that was made wrong from the beginning

Love this video, thanks for sharing 🙂👍

what a treat, thanks for the video

love your videos keep them coming

Hi Ron, love your channel.

This channel is amazing!!!!!

Thank you for what you do.

Dunno why the equ got removed, but it was damn funny. Awesome troubleshooting, thank you for sharing. Stay safe, much love. ❤️❤️❤️

Thanks, Ron!

Howdy, glasslinger. fairly impressive video. thanks. :)

great video as always

Glad to see you. Great video. Hi to Miss Kitty 🙂

Hey Ron, good afternoon, i was wondering about the turbomolecular pump driver you made afew years back could you please share the schematics if possible? Thank you for the great work

Wow, now that's a pro tip - using CRC Brake Cleaner for the POTS. Personally I have found some so called cleaners leave the POTS all full of goo and sticky. Potentially makes them worse. Thanks for the tip.

OH GOD thats something I always wanted to see done by you :D

Well done there ,yes was wondering where kitty was ,must be ur summer time there ,over here in new zealand its winter with frosty mornings .Enjoyed many thanks.

Ron, did you check the biasing of the push pull end stage? A good symmetric AB stage should not have this much distortion since the signal rides on an almost quadratic function. Also did you check for symmetry on the driver /phase inverter stage?

If you remember the old "No Noise" spray, used to quiet noisy volume controls, a few years ago, in a bind, I tried some WD-40. It worked beautifully.

I have never known a capacitor to be "reformed", throw the fucker out and dont be lazy haha

Great video

Tetrachloroethylene is the brake cleaner / dry cleaning fluid. from wiki: "Chlorinated brake cleaner containing tetrachloroethylene will on exposure to high temperatures (above 500 °F (260 °C)) or strong UV light decompose into phosgene and hydrogen chloride, both of which are dangerous when inhaled." so no spray on hot metal!!!

Top show!.

Any advice on what test equipment to buy for someone starting out? I would like to repair and build vintage guitar tube amps that I can not afford.

Hi Ron love your channel. I'm a new subscriber. Can I please request that you list the model of the gear you are restoring. I had to take a freeze the video on this one and it seems to be a Grommes LJ-3 Tube Amp. The last TV restoration you never even mention the model. Some of us like to follow along with the schematics which helps learning. Much appreciated. Hello from Australia.

I thought it looked like a 10 watt output amp. We had two of these at our Motel. One for PA address and one hooked to an FM tuner.

I love how you end your videos "okay, that's it." *click*

I think I saw a TM506 go by next to your current limiting device. It would be interesting to see a video about that. I also think I saw a custom plug in. Are you sitting on some treasure there?

Where did you get that printout of the schematic?

I love that laugh. "Four capacitors? Hahahahaha, I remember that TV, there were like eighty." Amen to that.

Fascinating. When watching a sine wave on an oscilloscope (and not a spectrum analyser), at what percentage distortion does it start to become *just* visible? Thanks.

You are AMAZING! I love it Thank you so much for this fantastic channel.👍

I have always used some type of cleaner-lubricant. Back in the day was tv tuner cleaner. Recent years I have used a couple varieties of Caig De-Oxit. Any reason or advantage using CRC Brake parts cleaner? No residue? Grease-cleaning capability? Cost?

Ron on the road again 👍👍

Good work

I see you are a fan of the Tektronix TM500 series of test equipment. Do you have any interesting plug-ins? Is that HV power you were using for capacitor leakage testing a commercial design or is it home-brew?

Quite a lot of even harmonics for a push-pull amplifier. Is there something else wrong, maybe the phase inverter?

love tube amp videos

What is the output impedance of the amp?

Would be interesting to see the curve shape (oscillogram, time domain) of the output voltage. Does the distortion come from the change-over of the push/pull output stage, or does it come in at the peaks of the voltage (maybe sagging power supply?), or does it come from the phase inverter, or.... I love your videos, Ron, keep them coming!

Ron I built your electronic circuit breaker, and it is working perfectly! Are you willing to share any insight on the current limited high voltage supply that you built into the Tektronix Rack? For info, it looks like Ron is using a HP 3582A 0-25kHz Audio Spectrum Analyzer.

Just before the amp started motorboating, you used your clothes to clean out the tube holder. I know that's totally unrelated , but I think you're so awesome. I paused video and I can't wait to see what's coming next. I think you're great!

Nice! Do a video with that Gow-Mac Gas Chromatograph. I want to see that.

You would not have blown the speaker if Supervisor Kitty was there to keep you right😺

If i could have chosen an elmer, this would be the one.

Had a pa .amp had 4. 6l6 did that the paper speaker cone caught fire when I was a kid .🤗

That's from the 70s? Looks more like 50s from the components, especially that function switch. (Which looks like it is from the 30s -40s but could still be found later.)

that thing would make a good unique door stop though....although i do like a little distortion when i clip my amps lol

The scope is displaying "Overload" when you increase the signal. Maybe that is why the harmonic levels indicated are so high. Try to adjust the scope so the signal does not go overscale in scope mode.

Is that amp one of ,the Heath kit, for the Am and Phono.

These videos make my day! As a gay Aussie guy I just love them and what's wrong with valve amps? My Primaluna Dialogue Premium HP Integrated Amplifier running EL34 output valves sound excellent so there! LOL

Ron, got an amp that needs repair. Still doing repairs ?

Hey there.... i'm enjoying some of your videos. Thanx, please keep'em coming. So at the beginning of this one I noticed two devices you were using. One being, I think you said an electronic fuse (not sure??) I guess it is a current limiter?? And the other was your high voltage variable bench supply I think. Either way they seemed very impressive & even more importantly were they or are they homebrew?? Did you design & make them yourself?? They look to be that as I couldn't see any manufacturer names etc.

Hi, at 43:48 and also several times later the analyzer displays OVERLOAD at the lower right corner. The spectrum does not change much when the voltage increases above that level. I expect the analyzer input is saturated and the spectrum shown is incorrect.

Did you make the fuse box you were using?

Is your electronic fuse homemade? Can you post a schematic? or if it is manufactured can you provide make and model? I could really use one of those.

ok, ok... i think i missed the electronic fuse with the cycles setting video now i want one. Ron, where can i get the diagram? thanks :) great tube videos

Someone’s probably already commented on this, but putting a square wave through a speaker is almost a sure way to blow it out even at low power. That ramp up on the start of the square wave draws a huge amount of current. By the way, this was one of the most entertaining videos I’ve seen in a long time! Good job!

Good one, Ron. Any possibility the output tubes are mismatched? Bell always made top notch audio amps. Tell the cat to stay cool!