Amazingly Original Pre-War OAHU Amp Gets a Tune-Up 

Congrats on 100K, Doug. Your dry sense of humor was the draw for me. Your electronics acumen keeps me coming back!

Congratulations on the 100,000 subscribers. I as well as your followers greatly enjoy your educational videos. To have Uncle Doug as a teacher in a classroom would be an excellent experience, although You Tube is just fine. 100,000 followers is nothing to sneeze at. It is a valuable statistic that proves what you are teaching is very important and needed by 100,000 followers. I personally feel your contribution, dedication to teaching and your expressive personality is the best that RU-vid has to offer. Thank you for what you do.

Glad you got your plaque, Doug. Back when you emailed me about it and said you didn't think you'd get one if you're not in the partner program, I told my wife I was thinking of sending you mine (which is still unopened on a shelf) as a thank you for being an inspiration to me and for being a friend. The only thing that stopped me was my wife said I should keep it and give it to one of my girls who might like to have it. But alas, all's well that ends well. Susan has given you your well-deserved mark of approbation.

i know this was 2 years ago . but still congrats on your award. Your wonderful knowledge of these circuits , has taught me loads . your a great teacher for sure.

I wish you could see the smile on my face when your video showed up on my notifications. I'm sure I'm not the only one. Thanks Uncle Doug.

43:07 Oh my goodness, UD! The imagery. 😂😂😂 Congratulations on your plaque! Well deserved.

Congrats on the milestone and "major award" Uncle Doug! 25 years ago, a fella brought a similar Oahu amp to me to try to get up and running. This was in the very beginning of my amplifier repair journey and all I had for reference information, was the Tube Amp Book and could not find anything similar and sadly had to return it to the customer--it was also badly hacked up by TV repairmen over the years, and I just couldn't make heads or tails of that little amp. This example is museum quality. Thanks again for all you do for all of us!

Every time I rewatch these I get more from them! I just restored a 1927 Atwater Kent 37 with an 80 rec and transformers and caps potted in tar.(fun) I don't think those old guitar amps can scare me much anymore (thanks to you of course)

Congratulations, Uncle Doug. An award well deserved. And again, another great old school lesson on the early years of tube design. This video defined a great deal. So glad to see you back... I was having Uncle Doug withdrawals. And as always.. Thank you, Professor.

That debit card addition is brilliant!

Great as always. my world stops when a new uncle Doug video gets posted!

The award could not go to a nicer guy, and as always a very informative and top notch video thanks for everything!

That is a sweet sounding little amp... now. Nice work Uncle Doug. Thank you, especially for the in-depth descriptions! You're the best. Congratulations on the plaque!

Hello again uncle Doug. I’ve been chasing an old mystery amp for a week and half. After identifying a coke bottle 80 and 6n6 sitting in a chassis that looked familiar I put in a successful bid. One poorly lit photo barely showed a domino capacitor so I knew it was much older than advertised. It’s a single ended Oahu and sounds beautiful. After researching and many identifying photos mine is the only one without a power light or fuse. The seller played it for me. He insisted. The chassis is absolutely spotless and has been minimally upgraded. Utah field coil 8” What I’ve learned from your videos and teaching style is paying off but I’ve only scratched the surface of what I need to. Thanks again. Bob

Congrats on a very well deserved Award. Hope to see you with many more.

Bless you for sharing your wisdom with your growing community 109K plus!!!

That amp looks like it just came out of the factory! I've never seen one in such pristine condition! Superb!!!

I think that old amp has a beautiful tone. Very informative video. As always, thank you for sharing your wisdom. 👍

Congratulations Uncle Doug. It’s a good milestone to achieve. I have commented several times and find your videos highly informative and entertaining. Watching your videos has inspired me to and shaped my direction in building my own guitar amplifier. Thank you so much. I would love to share my own progress with you. All the praise aside. Looking at that Oahu amplifier, it looks very similar to a Kay Amplifier that you did a year or 3 ago. Similar build, components, nice fret work, umbilical for the the field coil/speaker, and the additional choke. I like them both, but they are definitely odd.

Congratulations Uncle Doug on your RU-vid award! You must feel a bit proud to know you've reached the hearts and minds of so many of us. You have taught me so much with your no nonsense, thorough explanations of how amps work. I am sorry that I have not been able to support you monetarily as I'm on a somewhat fixed income (oddly named it seems) BUT I do have a collection of all sorts of vintage tubes! If you ever need a hard to find tube please contact me and I will see if I have one for you. Of course I don't have extra GZ34's 😢 but I have The tubes you are showing in this video and many of my tubes are NOS. Anyway, thanks for being you and taking the time to teach.

I am curious if the amp actually had shorting input jacks as shown on the schematic; amplifiers of this vintage often did not. Also note that a problem that can arise when the input stage has no grid-leak resistor is that a small voltage from the preamp tube grid can be fed backwards into the controls and pickups of the guitar, leading to crackling noises when the guitars volume is adjusted (which is the reason why you might see a capacitor between the input jack and the grid of the 1st preamp tube, to block DC from getting to the guitar's controls). The possibilities are legion for hum induction in an amplifier constructed like this. The 1st filter stage capacitor has its own ground ---- bolted, or riveted? ---- and the 2nd and 3rd stage filter caps have a separate ground several inches away through what looks to be a riveted-in-place terminal strip. Also the input jacks are bolted directly to the chassis without isolating launchers. All of this mechanical grounding was originally done to a heavily painted chassis without the factory taking pains to remove the paint around those holes, and 80 years later it can be pretty much guaranteed that there will be oxidation and galvanic corrosion underneath those bolts and input jacks, and especially at the riveted ground points for the terminal strips. Unfortunately it can be a big job to undo all those grounds and clean the metal and put them back together, and it's certainly not in everyone's budget, but it can be sonically rewarding (greatly lowering the hum and background noise floor) if one has the patience, or the budget, to do it. One pointed comment pertaining to safety; I would recommend attaching the ground wire from the power cord *directly to the chassis* and not to the frame of the filter choke because you are relying on the 80-year-old bolted connections holding the choke in place to connect to ground electrically through the frame of that choke ( the bolts and the chassis are probably oxidized underneath the monting tabs of the choke). This also might tend to induce eddy currents into the chassis, increasing hum.

Thanks again, very educational, your teaching skills really shine through. The paint is an inspection mark, we do that to indicate screws have been torqued and checked.

Terrific Video Uncle Doug!! Can't wait till it gets home to play its matching steel through it. Congrats on the 100,000 subs!! BigDave

I scored a nice Oahu square neck acoustic 'Hawaiian' slide guitar 2 yrs ago. Tracked down a genuine square Oahu slide. Cool to see an Oahu amp! This company was here in Ohio (Cleveland).

Congratulations! Your willingness to share your knowledge in a relaxed and humorous manner certainly deserve recognition. A beautiful vintage amp with great sound. I hope the kitties are well and not up to shenanigans.

Take it out to dinner and buy it flowers :-). UD you crack me up! Classic. Missed a cameo from the kitties though.

I agree doug its beautiful and if you are that excited about an amps appearance , the sound wont dissapoint

After Uncle Doug finished updating the Oahu and hearing the output/tone imagine Page, Clapton, Richards using it for recording !!

Was just thinking I wish there was a new Uncle Doug video. Looked at RU-vid, and there it was. Damn going to try to try that again tomorrow.

That is a very handsome plaque. Richly deserved.

Congratulations on your RU-vid award you deserve it. Always enjoy your videos.

glad to see you back. congrats

Wow! That amp puts out some rich harmonics!

You are still, the man, Uncle Doug.

@43:16 - wow😆 Uncle Doug ...just ... wow!

That sounds really good

Awesome, display your award with pride, you have earned it.

Keep the vids. coming they are "the best", and greatly enjoyed !

Kind sir, YOU ARE THE BEST! Thank you.

Hello First, congratulations on RU-vid recognition for your fantastic broadcasts and lessons. You really deserve it. I am such an average listener very happy about it. With great respect Henry

Congratulations!

Hey Uncle Doug. Congratulations on 100K. Now as for people that think the plaques are silly. Well there are over 100,000 people on this planet that don't think they're silly. 100,000 people who are interested in what you have to say, who's lives have been enriched by your knowledge. Mine certainly has. Well done.

Dear uncle Doug, congratulations to your 100K. You definitely deserve it 🙂 if not more . For me you and your videos belonging to the kind of content that made RU-vid so famous and unique and is the reason I still have it. It is honest, educational, non profit, and with a lovely sense of humour. You are one big influence that brought me into electronics and I hope you ll stay on air many years.

UD Rusty, Jack, Casey and Ollie congratulations on getting over 100,000 subscribers, thats a remarkable achievement. im glad to see Google/RU-vid are not the evil dark side and recognized you all even though you dont allow them to profit from your content. the amp sounds fantastic! im sure glad in this day of consumption and throw away after a few years of use, that you keep this great historic equipment alive and useful.

It is always a red letter day when a new Uncle Doug video is posted. Thanks.

Big fan for many years here, thank you for sharing your knowledge & preserving these pieces of history so carefully. Bravo!

You earned it Unc!!! You lay down some sweet videos and so many teachable moments. Shame you haven't cobbled together a DVD collection to educate the young ones. Who knows, maybe that's forthcoming. Love you, Bro!!!

Oh also Unkie,,, Pretty cool trick and great tip feeding the 120hZ audio into the input!

Congratulations on the subscriber goalpost! Hopefully the same high quality of educational material just keeps coming. What a lovely channel.

Congratualations with the +100.000 subscribers and with the recognition you received for this event from You Tube. If there is one thing positive at the covid pandemic is that I discovered You tube, and more particular your channel. I graduated in Electronics in the mid eighties (for some reason we never learned about vacuumtubes, although all TV's in that era worked on vacuum tubes ...), but I never ended up working in electronics. It was by seeing your videos that my intrest in analoge electronics got a wake up. I digged up my old studybooks and looked for hours at your videos. Now am I building my first tube amp and I am very glad I rediscovered my intrest in electronics. Thank you!!

Another excellent video. I'd been "hang'n out" for a new one. Thank you.

Hey uncle Doug great to hear from you

Congratulations on your subscribers award Uncle Doug!! and thanks for another video treasure :)

Two thumbs up Doug. Going to be late getting into my own shop this morning, Got a Uncle Doug vid to watch. That's almost like Christmas morning.

Congratulations Unlce Doug! Your a wealth of knowledge for Us! Thank you greatly for sharing it!

Very nice range of tones. Enjoyed this one and the very good explanations of the technical circuitry...

WOW! UD, I remember when I started watching your wonderful channel, that you had like 50,000 subs! I am thrilled and very happy that you have crossed the 100,000 sub mark! That is a very monuments occasion indeed! I must now offer my thanks and deepest gratitude for starting me personally along the path of tube amp repair! I was interested in amps before I found your channel and found most of the information to be confusing and contradictory, your channel however, was and is clear and concise and I personally am forever indebted to you for sharing your vast knowledge of tube amps with us mere mortals, lol. Thanks for all you do and if anyone reads this and is interested in going on to work on tube amps I HIGHLY recommend UD's how a tube amplifier works videos to get you started!! Again, words cannot describe how grateful I am for the knowledge I have learned from watching your videos!! Peace! And greetings from Oklahoma!!

Congratulations Uncle Doug

Congrats Uncle Doug,much desrved award,its a testament to your excellent and straightforward teaching skills that even an electrocutional hazard old mechanic can understand! cheers!

Embarking on a journey of vintage gear is truly a step back in history .You have a gift of presenting an overview of how things were done and do so in such an educational and informative manner.Always a treat watching your videos.Cheers from Canada.

Congrats Doug! I always watch your videos and love the sense of humor, especially when it pertains to Juarez.

Congratulations on the award. Well deserved!

Congratulations Uncle Doug!

Congrats on the award! Fun videro and supprised at how good the old girl sounds.

'...Had to take it out to dinner and buy it flowers...' You sir, are a wag. I learn ever more watching your content. Congratulations on the 100k - fully merited.

Congrats on your award. Greatly deserved.

Nice restoration on the amp, and a nice plaque from RU-vid!

Uncle Doug, you are my Rock, when it comes to working on Amplifiers. As you know, it's been a few years now, since I became inspired to learn this stuff. There's a couple other channels I watch. But when I am looking for die hard, bottom line, correct information. I ALWAYS go back to see what you have to say on a given subject. Thank you, for keeping me and many others inspired!

Nice catches on that non-schematic schematic. Wow, such a gorgeous, scooped clean tone on that Oh-Wahoo.

Very Good Video Uncle Doug! I Grew Up learning on circuits similar to the Oahu amp. I had an old ValveCo amp I played through practically the same circuit as your Oahu.

Congratulations Uncle Doug! Woohoo!!

Congratulations on your RU-vid Plaque!! Another great and informative video, thanks UD

Greetings uncle doug! Is so nice see a brand new video of yours. Thank you so much!

'"Take her out to dinner and buy her flowers" got me chuckling Doug !!

43:09 and just when you were hoping for a cheap date Uncle Doug :) Congrats on the 100K viewers and many more to come

Nice to see you here agai, Doug!

Congratulations for your RU-vid channel...... thanks for all your hard and enjoyable work. 🙏👍

Congratulations Doug!

Such interesting material for tons of people. I don't know diddly about old tube amps other than I like them. I really like to hear and see you talk about them. Thankyou Doug.

Congratulations. Well deserved reward.

Sometimes is does take dinner and flowers before you can get any penetration. That cracked me up. Congrats Uncle Doug!

You are a true historian Uncle Doug. We need more of you to stop history repeating itself. Beautiful amp wonderful restoration work. Joy.

The reprint of the 1937 Sylvania tube manual can be useful for these amplifiers, as it contains many of the two digit tubes and other common early tubes. It also contains some that are still around today ....6L6, 6V6, 5U4 which at the time were new and state of the art.

I’ve been going through Uncle Doug withdrawals😵‍💫

Uncle doug new video!!! time to take a coffee, relax and enjoy. Again, another great video and amazing teachting skills!

Congrats on reaching 100 000 tube twiddling maniacs around the globe Uncle Doug. Could you ever imagine reaching this milestone when you began this channel..! Kudos to your warm humour, steadfast principles and the helpful contribution of ole Rusty, Jack and the rest of the 4 legged furry crew, thanks for all the joy you have given us. .. greetings from South Africa.

Wow, sweet amp! Thank you, Unkie Doug!

Good to see you again, Uncle Doug! I saw a Patreon payment sent, got exited so checked and there ya go! Another Uncle Doug video! WooHoo!

That amp has the exact same handle as the Gibson EH-150. The grille cloth is absolutely amazing!! And congratulations for the 100K!

Congratulations Doug, 'keep on rockin'...

oh man! I really needed my Uncle Doug fix!

I have the same amp. Mine has the wood on the front delaminated. Mine still works but being as old as it is there's probably a few components that are getting tired inside. I thought about making a new grill for the front but I may just sell it as is and let the next owner decide what he wants to do with it.

I would pay good money if uncle Doug put together a textbook of amplifier repair knowledge and instructions - maybe a series of them that goes from beginner to advanced. Not sure if this is in his interests, but I think it would be awesome.

Congratulations Uncle Doug, you are well deserved for this award. Thank you for another great video, this amp sounds fabulous.

That Oahu has a lot of character. Keith Richards has one in his stage chain. Congratulations on your 100k! Give Texas my best!

Hi uncle Doug, I hope you and family are doing well. I do same with containers for parts when I dissect parts on a chassis , lol. Nice Oahu amp! And as always, thanks for sharing your knowledge! ;-)

Congrats on the award! It is a tribute to your fine work. Thanks for the look.

Hello Uncle Doug. It has been a while since I watched you and always nice to view your vids. I have a 1936 Northern Electric Radio Model 514 Broadcast plus 2 SW bands, made in Montreal Tombstone radio. It has a #80 tube. The unit use to be at the family farm.

What a completely beautiful thing! Everything about it is stunning! I'm only halfway through the vid but I'm very excited as I think this may guide me on my great grandad's radio he built in around 1938 - apparently they listened to the declaration of ww2 on it the next year. I'm thinking to try make it into a guitar amp using as many of the original components as possible, as AM radios are near useless in the UK, there's no schematic and I think it was either a DIY kit or a circuit my great uncle Norman dreamt up. I plan to piggyback a bluetooth receiver somewhere, so I can still play old radio shows through it too

Congrats! This channel has been a great education for me, thanks for sharing your knowledge.