Late-40's Mirovox Guitar Amp.....In for Repairs at Rusty's Workshop 

Greeting from New Zealand Uncle Doug. I'm Tony Pepers, the inventor of Rocket Sockets. I appreciate the plug. It's pretty crazy how much traction and support these have had all over the world. The original design was simply me looking for a solution to not damage guitar pedal artwork or paint jobs. I searched the web for plastic tooling and struggled to find anything. So I purchased a kitset 3d printer and designed and printed an early version in PLA. They were of course quite a bit far removed from where they are now. They would wear out pretty quickly being of a soft plastic and also the nature of FDM printing not being very strong. When other people started asking if they could buy from me I had a feeling I was onto something. I printed and sold about 150 sets of them. A few years went by and one day I woke up and decided to go see a local plastics manufacturer and have a chat about mass production in a more durable material. I then launched a Kickstarter campaign mid 2019 to help get the tooling made up. I have since shipped out over 2000 sets and demand is still high. I'm extremely happy that a little piece of my kiwi ingenuity is in so many workshops around the world and is making life easier for so many people. Keep making excellent videos!

Uncle Doug, You sir are what the internet was invented for. Thank you for your wonderful educational contributions! PS R\The car is stunning!!!

Like you, as I get older, I find that the number of times I'm wrong continues to grow. Also, and I asked my wife, the number of times I'm right continues to decrease.

Old amps, old hot rods, and no virus! It’s a great day! Good to see ya Doug.

I often re-watch all of your videos as you're the best teacher, easy to listen to, thorough, detailed and explain everything in an easy to understand way. I've learned so much from you. Thank you Uncle Doug, my favorite Uncle! 🙂

The sublime pleasure of an honest gentleman at work. Even when I have no clue what’s going on beyond “amp make loud”.

During this time it’s people like Uncle Doug that reminds me of what I use to like and respect about the USA as a nation of people. Cheers from down under

I used to watch Bob Ross when I was a kid on Saturday mornings, now it’s Uncle Doug...

A 70 year old that still goes out to play. (The amp, that is)... Respect.

Uncle Doug . Old TV technician here and to me that speaker looks just like ones I would see in console stereos from the 50's . Love your videos , I dont repair anymore but I think I still have cleaning fluid in my veins :)

Great amp repair and tips. Geez Louise, the rat rod has turned out just amazing, UD!!!

Hello Uncle Doug & Family, Ollie and Jack keep your hands free to work the controls. Great repair, I learn a lot in every video, Thank you. Them cat's been practicing. You always do such nice work on the amps and rods. Glad your doing well. All the best, Cass.

Beautiful job Uncle Doug! You fixed every problem your customer had! I'd love to hear what he said; surely he'd be 'over the moon'! I love your unique '30 Ford.

What an incredible engineer... your ability to see clearly the problems and solutions is what is missing in our newer generations. Hopefully we can resurrect that ability... Although i also know its inborn.

allways an inspiration to see the passion, experience and work of Uncle Doug

I’m not a musician and the only time I’ve ever been interested in audio amplifiers used for AM modulated transmitters, but your troubleshooting process is interesting and I picked up a few tips your videos are entertaining thank you.

was a Sunday mechanic in Berkeley~ climbing on one's back, get up for tools and get back down there~ was part of the job~ many times per day~

I love the deco lettering on the Mirovox control panel as well as the classy grill cloth. Great job of bringing her into this century.

Really great repair video on that '40's Mirovox amp. A really super nice job on the front suspension of that 1930 model A street rod as well. Thanks for sharing all of your hard work and making it look easy.

Regarding the 15" speaker in the Mirovox amp found on Reverb. It's obviously a TARDIS (note blue color and call box shape) so of course it's bigger on the inside than on the outside.

Greetings from across the pond, I really look forward to your uploads, nice sprinkling of irony and masses of information. Many thanks.

It's always a good day when I see that a new Uncle Doug video has been posted. The Mirovox amp sounds great, with nice clear treble.

Onkel Doug macht es wieder, großartige Verstärkerreparatur, Sir.

I started watching this in the bath but thankfully continued on my PC later - love it when I have to take notes like I'm at a university lecture! Never before has someone explained output transformers 'refelcted impedence' so perfectly. Oh and the hot rod - Thats how ALL cars should look. Simple, classic, elegant. Pure beauty.

Yes! Now my Saturday is complete!! At least for the next hour, lol

Now when you're playing with your carpicture me my work is working on a big old machinery and getting it alive again especially old diesel stuff, you are the best Uncle Doug!!!!!

The control panel is absolutely gorgeous!

Another awesome video! Thanks for including the output transformer turns ratio refresher. Looking forward to the next video.

great to see all the obscure amp's you showcase, plus the tech tip's, thank's Doug,

Uncle Doug I've always loved your amp work but your hotrod work is stunning One mean looking machine

I thought the control panel was so super clean! How could it be that old? But as we soon see, this amp is a fascinating story. This is a great example of how to evaluate an amp and logically determine what your troubleshooting strategy willl be.

If anyone was going to sort that one out without a schematic, it was you. Beautiful clean sound out of it too. The master volume pot on my amp was making an awful scratchy sound when it got up to around number three. So I put the ohm meter on it and saw it was going haywire at that range. I took it out and opened it up and noticed some of the resistive material had come off the track and was a mess. I ordered a new one, 100 k, and replaced it, and it works like new again.

Thanks Uncle Doug.. Great Video as usual.

I'm sure the customer is ecstatic with the results of your repairs! You really hit it out of the park on this one. Great work and sweet sounding amp! 2 thumbs way up!

THANKS for keeping your videos free from ADs!!

RIP Jeff Beck. Ace British guitarist and Hot Rod builder.

Doug, you are a master craftsman. I love your attention to detail. You must have been born Virgo. I love the desert and the doves in the background audio, gives me the feeling of the Zen that you have. If I was your neighbor I would be there watching and leaning and giving a hand if you needed. I build and repair vacuum tube amps and have a love of the old Western Electric circuits from the fifties. I did not learn from the technical engineering background that you have, but more of a street level guitar guy. I have been "shocked" into a technician that you would like. Your dry humor and appreciation of design engineering is so spot on to the way I think. I like to think the things I build will be there fifty years after I am gone, unlike the throw away culture that we have today. I would give you and the cats a good amount if I won the Lottery...I just know I am getting great value in what you create on your channel now. Thank you for doing what you do.

Gave this one the thumbs up before even watching it. Got to get my repair shop open for Saturday Walk-in service. I'll watch later. Thanks Doug.

Great repair Doug..Love the explanation and fix for the volume and tone pots. Very informative, I've learned a lot here Doug. Nice old beast too. Great sound. Thank you for sharing, I'm catching up with all your vids. Great stuff..Ed..U.K..😀

Those rocket sockets REALLY are a lifesaver, not regretted participating in the kickstarter!

Beautiful work on both the amp and your ride

As usual, great explanations and commentary as well as a troubleshooting, repairs and mods. I like this amps face and sound. It's so cool and rustic looking and works as one would expect it to function during various adjustments. Another great fix in the can! Beautiful custom fabrication and workmanship in the connector and pro install of the discs. I love it and you gotta always take many test drives... ;) What a beauty she is now from what she was... Wow!

Very nice and your little tips are the icing on the cake.

"Well, originality kinda flew the coop with this one a long time ago." Got that right. Lol.

Just loved your Joe Walsh / Funk 49 rendition. Joe was one of the biggest influences to my early days. Thanks for that!! Ahhh...the memories of the 60s. (at least as much as I can actually remember ...lol)

OMG! One of the best sounding amps I’ve heard in a while. This beautiful thing sings! ! ! Not one effect needed... the breakup is... To. Die. For!

I’ll bet those 6v6s are a lot happier. Sure was a nice Saturday surprise another uncle Doug video. Nice job

your eye and expertise for details regardless of the task very impressive. always enjoy thanks for your time.

This is excellent and I particularly appreciated the explanation of reflected impedance. Thanks!

"Having the wheel depart from the vehicle." Uncle Doug sure has a way with words. 🤣

A joy to see your car and how its come together. It's like to see you fix though how you fix an amplifier.

In memory of Rusty I am now subbed.

As always,a joy to watch your videos.Enjoy the fabulous ride.

One of my favorite repairs. I enjoy watching you dissect problems and brainstorm solutions. Very entertaining. Thank You, Sir!!!

UD, your voice on a Saturday night during these uncertain times is good for the soul. And I have to say that, although I'm always a sucker for your output transformer winding ratio mumbo-jumbo, tonight's 4 minute speed round was pure magic. Bless you Bother. Thanks as always, -RF

Cool amp indeed and it looked like a real challenge. Also what a car!! Wow!! Well done!

Uncle Doug, I just love them old skewl Hot Rods and this is another work of art, such a talented youngster you are. Rock and Roll and Hot Rods, what else can you ask for?

LOVE those Rocket Sockets! Never seen them before, but since they claim not to scratch panels, I'm all for them. Nice job, Tony Pepers! The hot rod is definitely lookin' Classic!

Great Video Uncle Doug, what a master Fabricator you are!!

I KNEW there must be a transformer placement commandment from God! I just knew it. That explains a lot.

A "modern looking speaker" older than me! Makes me feel very modern. Thank you uncle Doug.

I had a dream last night that I got hold of an old Cushman scooter and fixed it up. I slept through the night pretty good I thought but was dead on my feet all day---ya know, like I'd been working on a scooter all night. :-)

What a little Gem! Nice plating too!

One of the best channels on RU-vid. The amount of knowledge and experience demonstrated in your video's is outstanding! Thank you for your time.

What a beautiful quaint little amp 👍🏼

Also @36:20, regarding xformer winding output ratio, priceless information, along with other vids where you have shared as well ;-)

Thanks for the video, my Cats were disappointed... they were looking for their rock stars!

Doug, it sounds Great

thank you Uncle Doug, my art is also on the wall at the post office 95424~ am gettin' around, thanks to your support~....Jayster~

Great job, Doug! I bet this owner was very pleased, too :-)

Uncle Doug been practicing!

Hello Doug! It's amazing how many unusual, but nice amplifiers come in to your shop for repair. Some that admittedly I've never seen before.This one is no exception; however, they all tend to resemble either a Gibson or Valco in circuit design (and sometimes a Fender resemblance). That was a good thing you did by moving the OT back to the chassis rather than have the customer live dangerously having B+ exposed. Those one meg pots remind me of a recent repair I did where the controls did the exact same thing this one was doing. Turned out where not only was the value off, but were Linear Taper which will give you all the gain at the beginning of the control. Calming down the bias a little makes things more relaxed instead of running borderline red plate. Enjoyed this video as always. :)

Lots of tech in that video. Thanks Uncle Doug. Nice job on the A, sexy and ballsy at the same time. I wish we could have heard it rumble.

Beautiful sounding amp!

Nice job. It would be nice to see a video of the owners trying out their amp for the first time when they get it back.

In 1970 my bud Steve Hansen got his license and his dad bought him a VW van. We were 16. We went to America's biggest mall in the San Fernando valley - malls were not yet a "thing" and the Glendale Galleria seemed like a miracle. It was my first ride in Steve's hippie van. The Galleria is the mall featured in Moon Unit Zappa's Valley Girl. So we drove to the mall. Steve and I both had long hippie hair. Now for an incredible fact of 1970 - having long hear was like wearing a badge in that year. Hanging out in the Valley with long hair was a dangerous affair. Hollywood and the Valley were two different planets. We entered America's largest (first?) indoor mall after parking in the lot rivaled only by the Disneyland carpark. We walked for a few moments and we heard someone shout - "right there, hippies!" I'm not making this up. A burly security guard in uniform and officer's cap approached on our nine o' clock. Everything went dark. I came to in a tiny room with no windows and two very unfriendly faces checking me out. A security dude had sneaked up behind me and rendered me unconscious with a chokehold. We spoke for a few moments after I turned my pockets out to show them that I wasn't concealing stolen goods. They let me go and I sprinted for the parking lot - Steve drove the magnificent van right up to my left and shouted "get in!" - he had opened the rear sliding door and I dove into the van. We took off, never to return. We were both hyperventilating and wide-eyed. They had let Steve go while I was unconscious. He had prepared our retreat not knowing if I was dead or alive or incarcerated. We didn't tell our parents, they were no help in that regard. Ah, the seventies. Later on our little escapade was well represented in the Back to the Future parking lot scene except we were the good guys in the van. The tempo of that scene is perfect. In the 60s and 70s a dozen people in Los Angeles, mostly Latinos and African Americans, died from chokeholds. In the late seventies chokeholds were outlawed in L.A. I was the first for the security guard. He was given a class in chokeholds. I miss the chollas and the cicadas. Sometimes it's like, "hey, Ya-Aa (the ancient indigeneous word for L.A.), Imma gonna Mojave for a day or three, be cool ya Big Boss Basin" - new statement of intent - Ima gonna Mojave, sounds like a song title. Aloha.

The most family channel ever. Really, every time i watch your videos i have a strange feeling like you are somehow a relative. So calm and comfortable to watch! Glad you are doing well, Uncle Doug! Nice amp but the car is just gorgeous! Wow! Stay safe! And best wishes from Russia! Yury

Cheers UD, good tip on pot values.

" A little wear and tear on the corners like most of us get as we get older". I have the opposite problem, I've gotten a little rounder and therefore have fewer corners!

One of my favorite sounding amps that you have resurrected. Clean & clear all while a bit of grit to add some imperfect perfection. Hats off to you Doug!!

Love everthing you did to the amp what a nice 1 ,nice update on the ratrod many thanks again for your very wanted knowlege

Nothing like it Fantastic on both the front end and amp. Thanks for sharing

Old School! Both the amp and the rod

Another wonderful Amp & Auto show! You are a pleasure, Sir. Thank you as always for your time and effort and toutalidge!

Beautiful work Uncle Doug. As per usual your tastes in all things are impeccable. Gorgeous work on the amp... That car takes my breath away. You are truly a master sir!

Wow.. That amp tone was so smooth and relaxing sounding to the chords that you were strumming. That Rola really sounds smooth, just beaitiful. From one old palm bearing packer to another. Great work! Cheers!

Great job on the video👍🏻

I must come back to this Uncle Doug. Doing errands now. I've learned a lot from your great videos.

Uncle Doug, I have a lot of respect for your broad knowledge set. Thanks for you channel, I’m blessed by your humor and talent. I share many of your interests. I suspect you will be disappointed with the steering quality. You have stacked 2 heim joints on each side which will allow a fair bit of variable toe out and in. Grab a tire and steer it and you will see the bolt holding them together tilt back and forth. Just eliminate one of the heim joints on each side and the problem will vanish. I also recommend that your steering brackets you fabricated be bent to produce “Ackerman” geometry. The pivot points at each end of your steering brackets should point at the center of the rear axle. This way the tires won’t scrub when taking a sharp corner. Love love love your work, God bless!

Another outstanding video! Thank you, Uncle Doug.

Thanks Uncle Doug, I've been taking a lot on board, it's enjoyable watching your videos, and very educational. I've been working on my Aussie Vadis 600R (about 1965 made in Sydney) for some time, just finished making my bias measuring socket adaptors today, and also today a nice bloke named David Browne in Victoria just completed the rewind of my power transformer which had shorted while with the previous owner. I'm going through it nice and slow, fixing things that need fixing, a lot of time and effort doing something that is an afternoon walk in the park for you. Keep 'em coming and I'll be watching :).

@28.28 I like your TS methods to determine correct POT resistance. (Have not used this yet) Thanks uncle Doug ;-)

Interesting, that lead dressing (or lack there of) looks very much like my 1947 Magnatone Troubadour M192-5. I've had that Magnatone all sorted out over the years. The beauty of these early amplifiers is the simplicity and cleverness of the design. Great video, thank you for sharing your time.

Thanks Uncle Doug...

Very good run through on this amp. A great improvement from where it was when you got it. You simplified turns ratios and impedance matching for me, stuff that I had forgotten long ago when I use to teach this stuff.

Man you do some cool stuff. Keep it up!

Another interesting amp video and car video. Thanks Unca Doug!

Uncle Doug, you are the master of the tube amplifier.

Super great vid and good work all around. Good to see you again Doug. It’s always nice to chill with you and watch you work while teaching us. Thank you. Cheers! ✌🏽🎸🏎

Come for the amps, stay for the Hotrods!!!