Видео

I used to say the exact same thing when I saw Wonder Woman

Uncle Doug, I completed this procedure successfully today without incident, thanks to your excellent teaching. When I measured 450 volts after switching on my Vibro Champ, I felt a good amount of respect, but I didn't quake in my boots because I had watched your video. I did the measurements for several 6V6 tubes and found the newer ones (JJ) were running much hotter than an old GE tube (which was at 12.5 W with the original biasing). I also liked the overall sound better with the GE, so left it in there. Once I have to switch to JJs, I will have to rebias the amp because they're running at 15.5 - 16 watts of plate dissipation. I know how to do that now. The measurements were interesting. I also took the opportunity to glue the tolex back down and polish the front, using methods I learned from your videos. The amp is shiny and sounds great. I'm using a step-down transformer with this US-made amp, since I'm in Europe. I ran into some interesting polarity issues with that. If one turns the (Schuko) plug the wrong way around, the step-down transformer outputs 234 volts instead of 117. Not very nice. I believe many people aren't aware of this. I got myself a model with a polarity check so this doesn't happen anymore (it didn't hit the amp, I measured first). What is the result of running an amp made for 117 volts on 234 volts instead? I wonder.

Hi, Uncle Doug-- I've got another dumb question. When using a dropping resistor between the rectifier and the 1st node, I'm getting wattage requirements in the mid-40's. But schematics usually show a rating of 5 watts or 10 watts. Does the power handling of the output transformer combine with the power handling of the dropping resistor? Cheers, and thanks for 75% of my electronics education.

What a great demonstration, Uncle Doug you were the best Nine years before, and you keep improving to this day, love you and your Channel.

The scene at the red sand dunes, felt like going to Mars.

I’m going through all these technical videos again preparing for my second amp build. Got to say doing a hands on project really helps me understand the nuances of these excellent videos. I’m having so much fun doing these projects and I don’t know if I could do it without Uncle Doug.

Hi, i have learn a lot through your video ! thank you! I've find an interesting schematic that work a bit differently actually the DUAL PRO FENDER from 1948 I don't understand how the signal get out of phase on this schematic could you help? thank you

❤

I use this guy. Love it. It’s great

Fantastic video! I am a little fuzzy however on what the function of the 5Y3 part of the circuit is for attaching the 325v DC current. Why is this used instead of just a direct wire?

Hey Uncle Doug, hope all is well. I just picked one of these up, same year. Is the GZ34 an acceptable drop in tube and are there any benefits to using it over the stock tube? Also, mine has a faint cigarette odor, any tips on safely deodorizing amps and cleaning tolex, etc…thank you for all you do, sir!

Uncle Doug you are a legend and still so humble. I can't believe you would clean your fingerprints off the metalwork. A hundred years from now when these fully restored Jewels are opened up by enthusiasts like you, they will be combing the chassis for evidence that Uncle Doug may once have graced these shores, just as you look for traces of a bygone era. Please leave at least one fingerprint. You too are a treasure according to at least 128000 people.

They were built to last forever. They came with a lifetime warranty.

This is more my cup of tea. I don't play a instrument but I do play records.

Cheers, Uncle Doug-- Thanks for all the education. I got a question about old transformers, the type with 2 black primaries. Are they interchangeable when using a 3-prong cord having black (hot), white (neutral), and green (ground) conductors? Thanks again for all the info!

Excellent - helped me a lot!

Poor Ms Lupe is crying in her grave

Bravo bravo bravo from Italia 🇮🇹

There is a significant error in all this, namely that turns ratio alone cannot be used to calculate impedance ratio. Impedance by definition is the vector sum of reactance and resistance. If the transformer is tested for its voltage (turns) ratio with no load on the windings, resistance is not being included in the calculation. The fact that the Edcor transformer specifications agree with your measurement of turns ratio only means the manufacturer has also failed to account for this. In practice, placing an 8Ω load on the 8Ω tap of this transformer will not reflect 8,000Ω to the tubes, because the resistance of the windings changes the effective ratio. This disparity can be observed by placing the signal source across the primary winding and making the ratio measurement with and without a load attached to the secondary. When the load is attached, voltage at the secondary will decrease. This translates to a larger ratio, indicating that the true impedance ratio is substantially higher than will be calculated using the method in this video.

Very nice, clear instruction Uncle Doug! I get it!! Thank you!! Sure helps me out! : ) PS: And great guitar playing Rusty! Woof!

nice old ford truck with a chevy engine!! cool stuff!

great tone for 4 or 5 watts. also its a beautfu amp! nice reverb and remolo!

Thank you for your time this is brilliant and it is giving me the answers i need in an constructive progress THANK YOU

In a quad, with parallel plates, could you pull one tube and measure that current, then remove that tube and put the other one in and measure the current of that tube. Would that give you an accurate measure of the current for each tube in the pair.? Thank You

Needed to add the names of the amps

Wouldn't 1K hz technically be ULF and not VLF? VLF I believe is 3Khz - 30Khz

After playing with VFD displays I was recommended to watch this. Very interesting. You explain it very good. Thanks

Sounds just sweet. Love that early REM type sound.

Dear Sir, would you share your knowledge, experience about audio interstage transformer: principle, calculation, etc. Tks.

I know i say this on every plexi video but the pains one would have to go to in order to devise a more confusing model designation system than Marshall used on these amps are unimaginable. Its gods own mystery why the hell they would use a 4 digit code beginning, often but not always with the numbers 1 and 9, making them seem of course like a date to the uninformed. A 1986 Marshall huh? Yes made in 1969. Wait....what? I thought... That it was an 87? Oh no!

Thanks Uncle Doug, the best amplifier Technician in RUclips Land , really enjoyed this build

58:48 "tightly twisted to dee snider's specifications"

Very well detailed. Very helpful. Thank you.

Thank you so much for this excellent tutorial. I'm about to try my first recone - a small 4" antique radio speaker. I've watched yout tutorial numerous times now and I have one concern - the use of contact cement on both the spider to frame, and on the cone to frame. How did you be certain to get centering just right before those pieces touched?! I imagine this is why you leave a small open ring around each component and the voice coil as a little fudge factor when dropping these components in place? But man, that speaker cone fudge factor sure is TINY! I think to myself a second shim around the outside of the voice coil might help centering before the pieces touch? I'm feeling more like using GC speaker repair cement for these connections in order to have a few moments of wiggle time to be sure I get the centering just right. Am I overthinking this? Sure would appreciate any additional insight regarding this part of your procedure.

Man amazing work you do! I love playing guitar and old tubes, but doing this would be difficult for me or at the very least so time consuming I should stick to guitar and have someone else build em. I can see it now... Uncle Doug's Amplification - Made in USA - and we need some good ole made in USA right about now. I was thinking as you were scanning the circuity in the vid...its almost like "a plate of linguine with wires everywhere" in there haha

You know, opening up a box on any other channel would be positively soporific...But for Uncle Doug its his best standup material!

In these shoes I would apply, power off, a small AC voltage to the speaker terminals & measure the AC figure on each output plate to be sure the turns figure is still within a small margin of identical.

Hi Uncle Doug. Quick question if you do not mind. At 12:29 , why not tape off the orange wire, center tap for the 6.3v heaters and leave the 2 100ohm resistors in place as an "artificial center tap"? I have to make this decision on a Twin that I am building. Some on the internet say that having the 2 100 ohm resistors in place can "save" the PT if there is a short on one of the tubes. However the amp that I am working on, like this one had both wires grounded + 2 100 ohms which defeats the "artificial center tap". Should I just lift the orange wire and tape it off? Thank you!

One thing that is especially endearing to me is when Uncle Doug says, QUESO. I know you're saying 'kay, sooo, but I always hear queso

I just picked up an Alamo Embassy that plays and sounds good. The effect doesn't work, though. When I adjust the speed and intensity does nothing. There is a remote foot switch input.

Doug, I just put the finishing touches on my own project, following almost all of your suggested modifications. Made all my bias measurements with the help of earlier videos of yours, and everything appears normal. This thing has an incredible sound and a tonal range that just blew me away. The overdrive when Tone + Volume are maxed out is so delightful. This amp is heading out tomorrow to spend a couple of days on a gig in the orchestra pit at our historic downtown theater, and right in time for me to not break my back rolling out the 4x10 Music Man I usually work with. I am so grateful for the inspiration and knowledge that your videos provided. This was my first attempt at a scratch build. Thank you!! I'll be heading over to your PayPal to literally put my money where my gratitude is. Your neighbor in the Lone Star State - T.J.

Great tips and tricks!

You know, Uncle Doug it's not fair for you to excel in everything you do. You are not contributing to the spirit of lower mediocrity that's. And you probably don't have an Art LA Fabrique degree making it all the more maddening and unacceptable today.

I wonder why they use green wire, of all available colors, for filament power? Is it historical before we used green for ground?Regardless, bad choice at this point in time from my point of view.

The fuse protects equipment after the switch. The breaker protects equipment between the breaker and switch. And that breaker in your house has many breakers behind it protecting each link between breakers. The principle that the switch precedes the fuse is universal. Nobody should be changing a hot fuse regardless of the application, voltage, or current available. If you tell me “just unplug it” you have just put the switch before the fuse and proven my point. Breakers and fuses protect equipment, not life.

The really rare wiring was done by Lola...L-O-L-A Lola...(La la la la Lola) (Her signature was a Kink in the power cable...)

Thanks for all the wisdom and info. By watching your channel for the last 4 years I've learned to diagnose and repair issues with my tube amps. Thank you.

Thank you. This is very helpful. Question… Could you remove the tremelo completely… then use the 2nd 12ax7 as another gain stage?

Sonho de todos guitarrista um amplificador lindo leve para transportar ótimo vídeo mestre Jorge Sul do Brasil

Hi Doug, I have watched your channel for years. There's no one on the planet that could hold a candle to your skill of building amps and drawing schematics and explaining everything and your outrageous talent of building hot rod cars like the plastic models I used to build and paint as a kid by Mattel. There's no one on RUclips that is as entertaining as you are. I find you to be a diamond in the rough. You just don't find older guys in my age bracket quite like you. I think the world is lucky to have someone like you doing these videos and hope you go on doing the things that you do forever. Brings me back to a time when I was a kid and loved guitars amps and hot rod cars and surf music, but like my sister once said to me, you can never go back home .You have a way of mesmerizing people with the way you speak and your vast knowledge of everything. People have no idea of your genius. All I can finish with, is saying thanks for the years of videos. Michel Newell from Niagara Falls, Ontario Canada