Brownface Fender Princeton and Silverface Champ "Double-Header"

In this video two amps will be inspected, repaired, and tested: a mint 1961 Brownface Fender Princeton and an equally nice Silverface Champ. Several different problems are encountered, including the all-too-common scorching hot bias of the Champ's 6V6 and a weak tremolo in the Princeton. Hopefully, the repair methods will be instructive.
Working on old, classic amps like these always presents an ethical dilemma: do we preserve originality at the expense of safety, proper function, and reliability......or do safety and functionality justify the replacement of original components? I guess it all boils down to whether you want a pristine display piece......or an amplifier that functions like new, for a reasonably long time. Only the owner can decide.
If you enjoy advertising-free videos like these featuring classic vintage tube amps, then please subscribe to our channel and consider becoming a Patreon patron at: / uncledougsvintageamps or making a PayPal contribution to [e-mail]. Thanks !!
If you are interested in obtaining a custom amp cover, please contact Joel Thomas: [e-mail]

[@UncleDoug]

NOTES: 1.) Because of their low PC and imbalance, the GE 6V6's were replaced with a matched pair of EH's. The GE biasing was retained in the video for instructional purposes. 2.) The Champ video was abbreviated due to time constraints. More work was done. 3.) Although the Princeton schematic show 30/30/30uf filter caps, the circuit actually contained 20/20/20uf.

[@Starcrunch72]

I noticed the 30/30/30 on the schematic as you panned over that, remembering the 20/20/20/20 in the blackface schematic before I received the amp mentioned below.

[@UncleDoug]

Yes, it makes me wonder if the schematic really is correct for this circuit. There were several other very noticeable differences.

[@davidfuller581]

Honestly, the EH 6V6s aren't bad tubes at all. Personally I like the Tung-Sol remakes more but they're quite similar.

[@srfrg9707]

Uncle Doug Happy new year to you Uncle Doug and thank you for all the very untertaining videos of last year.

[@Swine-O-Sonic]

Any time uncle D!!

[@HeliBenj]

A new video from Unc' Doug, the day just got a whole lot better

[@UncleDoug]

I hope it stays that way, Ben :)

[@DeadKoby]

8:00 Doug, you're not a total stranger... you're the mentor to many of us who are amplifier novices. I learned lots from your video series, and that basic understanding made it possible for me to go further. Tech books are like drinking from a firehose if you lack the rudimentary understanding.

[@UncleDoug]

Thanks, DK. But you must admit that sending a family heirloom to some voice on the Internet takes a leap of faith.....for which I am appreciative. Thanks so much for your nice comments.

[@repairfreak]

DeadKoby Yes...I’m proud and feel honored to call him my Uncle Doug as well. ✌️😎

[@fintimwhimbim]

🤪

[@michaelmerritt1722]

I enjoy that you stick with repairing amps. Others get too political. You have great humor and I enjoy your pets, Jack and Ollie, plus drone flights as an added bonus. Keep up the great work Uncle Doug!

[@UncleDoug]

Thanks, Michael. Politics makes people crazy. We need to focus on what's important in life......good friends, good pets, family, amps, and beer :)

[@edwardebel1847]

@@UncleDougThere ya go, Witchita!

[@JoelzombieThomas]

Thanks for the plug on my amp cover at 33:30! I saw the one on the brown face at the beginning and had a double take- That's not the one I made...? I watched on and did see it, and the rest of the action. I enjoyed making it for you, and the process of donating it to the channel. I'm glad to have had the opportunity to provide something useful to the channel by the man who's been inspiring and encouraging my tube amp pursuits for at least 5 years. I'm also glad it came out so nice, due much in part to your precise measurements of the original item, a very necessary ingredient in the making of the clothing it now wears. The majority of the remnant material now exists as limited-edition OEM replica shifter boots for late 1st-generation 4x4 Toyota pickup trucks, in both the tan and brown. I have yet to photograph and market those, but interested parties may like to search Ebay for my store, Blackndecker1 username, and Etsy for AGoGoDesigns for toyota 4x4 replica shifter boots and t-shirts. Doug, just wanted to mention also that I look forward to any portfolio photography of the cover when you happen to have time, and to your forthcoming videos in production as always.

[@UncleDoug]

I'm glad you saw my "advertisement", Joel. I really appreciate the cover and did my best to make that evident. I should have taken some photos while shooting the video, but things were pretty hectic and I forgot. I will take some soon. Thanks again and best of luck with your business.

[@JoelzombieThomas]

@@UncleDoug Thanks, I'm starting a new day job tomorrow, moving from house painting to ship painting on the largest dry dock in North America. But I'm still available to make amp covers, guitar straps, custom bags, and screenprinting embellishments on all.

[@NotMarkKnopfler]

You re-coned the cat? Your amp addiction is getting out of control!

[@crispysyd9190]

Lol!!!

[@UncleDoug]

Yep.....her voice coil was getting a little scratchy :)

[@valvenator]

@@UncleDoug Just don't leave any exposed speakers sitting around. KC might have a flashback and take revenge.

[@UncleDoug]

A good suggestion, V. Thanks :)

[@AdmiralQuality]

Like that old Brother P-Touch commercial. "I labeled... THE CAT!"

[@bluesingmusic3443]

That amp is absolutely PRISTINE. I don't remember amps looking that good back in the early 70s. Wow. What a treat. I'm amazed at that amp.

[@UncleDoug]

It truly is a gem, BiG. Thanks !!

[@bobross9648]

Hi Doug. I'm a retired electronics tech and really loved Nu-Trol back in the day for getting those old pots working good as new. Great job !! Bob

[@UncleDoug]

Both of my DeOxit sprays ceased to work properly, so I had to resort to my old standby......which does a great job !!!

[@pbrom99]

Uncle Doug, I started playing guitar in the early sixties and played through many of the classic Fender amps when they were fairly new. I have tried just about every amp on the market over the years and to my ears nothing beats the old Fenders from the late 50s thru early 60s. Thank you so much for sharing your knowledge with us. It is incredibly interesting to to see you walk through the circuits and explain how they work. Please keep the videos coming.

[@UncleDoug]

You are quite welcome, P99. We will :)

[@luthravin4774]

Thanks for sharing Doug!! I’m very fortunate that my 65’ Vibro Champ Amp is functioning and sounding tip top!! These videos are so inspiring!! That Princeton was so clean.. your work was flawless!!

[@UncleDoug]

You're welcome, Luth. Thanks !!!

[@boctok55]

UD, you are truly fortunate for getting to work on such fine historical specimens of the tube amp world. Thanks for allowing us to experience it vicariously!

[@UncleDoug]

I agree, B55. It's an honor to be trusted with such gems. You're welcome.

[@buzzawuzza3743]

Really glad to see the owner of that beautiful Princeton taking such good care of it, Uncle Doug.

[@UncleDoug]

So am I, FW. It's a family heirloom.

[@thomasburnett4712]

Wow! A double header with 2 of my favorite potential build projects! Thanks Uncle Doug!

[@UncleDoug]

Yep......so quit watching re-runs of The View, grab some whisky and start watching, Thomas. You're welcome :)

[@THEQueeferSutherland]

Thank you for spaying and taking care of little Casey.

[@UncleDoug]

You're welcome, QS. She's definitely worth it :)

[@chipsterb4946]

The metal screen together with the metal chassis creates a Faraday cage, and it can be helpful in reducing noise from single coil pickups, fluorescent lights, etc. I once had a power transformer that had a ground lead for an internal Faraday shield.

[@jensenbell]

Another great video Uncle Doug! I just had my 6G3 1962 Brownface Deluxe serviced recently (and due to your video education, knew a lot more about what my tech was saying)... and I was shouting at the screen... "Keep the blue molded... but test all the yellow Astrons!" ... they really leak after 50-60 years while the Blue Molded are miraculous. I get why you wanted to send him back a longevity prepared amp, but if those blue molded caps read exactly right, I would leave them on my own amp. I love my Brown Deluxe. It is sort of a perfect tone combination of my Blackface and my Tweed. It's loud enough for a band rehearsal and quiet enough to turn up in small studio. The Bias Tremolo is luxurious. The Oxfords were made with care between 61-65. They compete with Jensen Ceramics.. and in some ways out perform them in the reproduction of low end. Then Oxford changed their production methods and they get really bad after that. Jensen's also fall off after 65 - and then go extinct. Thank goodness for Chicago Telephone Supply! I'm using German F&T electrolytics now whenever it's time to upgrade my vintage fenders with fantastic results. When it comes to coupling capacitors I'm still too attached to originality. I know it's dumb. But it's kind of like collecting old things.. .you want it to be a time capsule. ;; sigh ;;;.. both of your repairs are going to last long and sound great.. and that's what this video teaches me. Love to your family. - J

[@UncleDoug]

Thanks so much, Jensen. Those who know me realize that I am a purist at heart. Heck, many of my vintage amps still have their original cords and filter caps......BUT when dealing with distant customers, different rules apply. As a consolation, I always send all the original parts back with the repaired amp so that it can be put back to original if necessary. Shipping is just too expensive nowadays to take chances on 60 year old capacitors, even if they are Blue Molded :)

[@ziccuj]

I have a '62 Fender Brownface Princeton 6G2 and the tube chart in my amp is on the side wall of the cabinet, not on the floor. The 6G2 is definitely one of Fender's best amps, hands down. You can really get a creamy overdriven sound out of this one without destroying your ears. It also works very nicely with a 2x12" or even 4x12" cabinet as a "mini-Marshall", much in the same way as its bigger brother, the 6G3 Deluxe which has even more gain. Thanks again for an excellent video and cheers from Finland!

[@UncleDoug]

You're welcome, J.

[@backspin6698]

I don't know anything about electronics (but I'm learning), but I love tube amps and playing guitar. And there is something relaxing and satisfying to watch videos of amp repairs from Uncle Doug and Brad the guitologist. And this amp is a gem. It's five years older than me, and it will probably play the blues long after I am gone.

[@UncleDoug]

Thanks for your kind words, B66. We appreciate your time and interest in our channel.

[@dyamariv3628]

Uncle Doug, always love your videos and your awesome sense of humor! Any chance you could show more of the soldering and actually fixing of the parts like the foot switch?

[@UncleDoug]

Thanks, DY. I tend to use a handheld camera while making the videos, and this makes work demos a bit challenging......but I can use a tripod in the future and show you the actual hand work if you wish.

[@AdmiralQuality]

You might find a bit more of that in Doug's earlier videos. And there's a few other KZbinrs with lots of videos on soldering technique, check out Mr. Carlson's Lab and EEVBlog.

[@UncleDoug]

@@AdmiralQuality To be honest, I have cut out a lot of the routine procedures simply to keep video length manageable. My style is to keep scenes short and to the point, and repetition of manual procedures would tend to prolong scenes.....and videos. If enough viewers wish to see these manual procedures, however, perhaps a compromise can be found.

[@Murry_in_Arizona]

bigclive.com's youtube channel has a couple of excellent videos on basic soldering and electronics that helped me and I'm as thick headed as they come.

[@michaelogden5958]

@@UncleDoug I enjoy watching the handwork also!

[@dkruitz]

Your channel is an inspiration! My daughter's boyfriend and I are trying to revamp a 1960 Gibson. And I will admit that it is a whole learning experience dealing with tubes LOL very enjoyable seeing videos like yours, thank you.

[@UncleDoug]

You're welcome, DK. Good luck with your repairs on the Gibson amp.

[@wegert1]

I have a quite a few miles on me as well. And, as I've aged, I've noticed that I've ceased to be able to emit electrons at the same rate that I once could...

[@UncleDoug]

Amen, RF, but somehow the old kidneys and bladder seem to work better than ever, especially late at night :)

[@goodun6081]

@@UncleDoug , hey, I resemble that!

[@goodun6081]

RockstarFarmer, please stop right there before the conversation turns to anode currents!

[@russellesimonetta3835]

Yeah none of us are as great as we once were but always try to be great once.

[@UncleDoug]

@@russellesimonetta3835 I'm still trying, Russell.....so far, to no avail :)

[@MrBrymstond]

@Uncle Doug It's always a great day above ground which is hammering at me, but just hearing the man with all the tricks of knowledge has more to share brightens my day! You always seem to know right where the problems are, no matter how long you've done it, it's still amazing to watch that. That little Champ gave that Fender Princeton a run for it's money. When I first started off I remember having a tiny amp like the champ or smaller and I stuck a mic on it and we only played where the house had its own PA system until I earned the money to have our own, then the agony to achieve the sound I wanted from my guitar and amp. Much Love Brother.

[@UncleDoug]

Likewise, Mr. B. Thanks so much :)

[@timothyryan6018]

Thx for the vid Uncle Doug-- that Princeton looks like it was made in Fullerton Ca. yesterday...

[@kenhancock8931]

Thx uncle doug. hope jack isn't to rough on her being inside. hope you have a great day!!!

[@UncleDoug]

You're welcome, Ken. They are maintaining a respectful distance and are still rather wary of each other. Hopefully, that will improve with time.

[@GeorgeK356]

A great "twofer" Uncle Doug. A pleasure to watch you work, and to listen in to your thought processes. Many many thanks.

[@UncleDoug]

You're welcome, TW.

[@JDPri77]

My cousin came to live with us in 1967 and she had an early Princeton and a Mustang for a guitar. I was about 9. I remember trying to play the Ventures, "Walk Don't Run", and some early Beach Boys, etc on that amp. When you cranked up that Princeton with the vibrato set just right, it took me back 52 years. As the years went on and played in my own band, I looked for more power with Twin Reverbs and other amps that focused on volume rather than a unique sound. But these videos have helped me to recognize and appreciate the unique sounds that various amps have. And, this one made me want to find my cousin to see if she still has that black-face Princeton and that Mustang.

[@UncleDoug]

Your cousin sounds like quite a girl, JD. It is surprising that music and familiar sounds can bring back such strong memories and emotions. During my years of jukebox restoration, there were certain songs that I could barely stand to play sometimes......connected to friends who had died, etc. And I agree, each amp has its own special personality :)

[@Andy_Yates]

KC with the cone of shame. Loving the progress she is making and always appreciative of your fun and educational content!

[@UncleDoug]

Thanks, Andy. She's fully recuperated and doing just fine.

[@wilson4180]

I love the irony of a Brownface amp serial number starting with P00.

[@UncleDoug]

Darn good catch, Mike. I missed it completely :):)

[@valvenator]

I caught the 'P00' part too (wait, did I just say that?) but didn't make the 'Brownface' connection (again, did I just say that?)

[@UncleDoug]

Yep, you said it :)

[@barrybartos7687]

@@AdmiralQuality This amp is a museum piece.

[@andrewmvenegas]

I’m sure you’ve been asked about apprenticeships. I am day dreaming about standing next you learning this fabulous trade/craft.

[@UncleDoug]

You would be disappointed, Andrew. Much of the time we are guzzling beer, playing rock tunes at high volume, and fighting off groupies......it's a wonder that any work gets done at all ;)

[@russellesimonetta3835]

Uncle doug. I thank you for the education. I had to watch your key videos many times over to get a handle on this , to me , magical art. I can follow schematics and understand the layouts compleatly. But i still struggle with applying the schematic with the layout. Maybe a tutorial on tracing out the signal path would help us grasshoppers

[@UncleDoug]

You're welcome, Russell. I will keep your suggestion in mind for the future.

[@Finom1]

Uncle Doug, I loved your video. very educational. Man you can rock it and make this old timer listening to you feel young again!!! Please keep it up, the world needs you!

[@UncleDoug]

Thanks so much, F1 :)

[@geemac7267]

Dang, Jack and Ollie have been practicing! Nice work as usual, Doug. I also have a 1978 Champ and love it.

[@UncleDoug]

Besides eating, sleeping, and making "deposits" in their cat boxes, they have little else to do but practice, GM :)

[@shaneeaston4027]

Both nice but the Princeton was a gem. I could tell by the giddy excitement in your voice that Aunty Doug will notice a spring in the old dog's step.

[@UncleDoug]

I agree.....and so does she, Shane. Working on wonderful old gems always peps me up quite a bit :)

[@abelincoln95]

Unc!! Nice example on that Brownface!! And the rare "Theodore J. Kaczynski"chassis stands!! You source the most unique equipment!!

[@UncleDoug]

Thanks, Abe. Coming from an old log cabin guy like you, any wood-related comments are highly anticipated :)

[@doughhole]

@@UncleDoug I read this in your voice in my head O.O

[@MichaelLloyd]

I was/am working on amp kit (Christmas present. 18W British style Marshall) and I saw the Uncle Doug video notice. What a great way to spend my lunch break.

[@UncleDoug]

I'm glad you enjoyed it, Michael.......now get back to work ;)

[@MichaelLloyd]

@@UncleDoug Lol... I think I have a preference for Fender amps. The kit is designed to recreate a British Marshall amp. It has turret boards (not a fan, I prefer eyelet or point to point). I spent an inordinate amount of time wiring the filaments but that is all on me because I was very picky about how they were twisted and positioned. Now it's packed away and ready for the nice long drive to Farmington, NM tomorrow (I'll probably finish it in the hotel). I'll wave when I pass thru El Paso, if I go that way.

[@MarshallSetUps]

Jack and Ollie are jamming at their finest in this video. I enjoyed this video as much as enjoyed working today. I have a brand new recording studio sitting in a box at home today. Thank you Doug.

[@UncleDoug]

Wow, I'll tell them, Marshall. Jack is currently watching the news with Aunt Carly :) Have fun with your new studio. You're welcome.

[@MarshallSetUps]

@@UncleDoug My hearing is crap, but the studio is nice and audible. Ha! CARLY! I was hoping for Ollie, because I had a wonderful cat named Ollie once. He was a jammer too.

[@matambale]

Really envious of the hand-crafted high-grade amplifier chassis stands.

[@UncleDoug]

Eat your heart out, M. Only the very wealthy can afford such glamorous accoutrements ;)

[@Mountainrock70]

I’m just now finding you. I’m chalking this up to the finest amp tech video I’ve come across. Thank you!

[@UncleDoug]

Wow, thanks so much, ST, and welcome aboard. So glad you enjoy the videos.

[@smasica]

Nice intro on "Long Cool Woman in a Black Dress". I had a '64 Tremolux black-face and it also used that same tremolo foot switch and speaker jack. Good times.

[@UncleDoug]

Yes, indeed, TM :) Thanks !!

[@rebelrelicguitars]

Oooh lala. Unveiling that Princeton made me scoot forward in my chair. A real treat.

[@UncleDoug]

Glad you enjoyed it, RRG.

[@rebelrelicguitars]

Enjoy it I did. Shared it on my Facebook page for those vintage amp enthusiasts with technical interests. And if I had my way you would be picked up by a television production and have your own tv show like Fast & Loud or Wheeler Dealers and hopefully not become over commercialized and open a restaurant nightclub etc...

[@djfrank59]

The Princeton has to be the cleanest I've ever seen. Amazing! i repaired one 4 years ago that looked like it dropped off the back of a train. Great video as always :)

[@UncleDoug]

Thanks, Frank. Glad you liked it :)

[@gizmothewytchdoktor1049]

uncle doug.... a rare treat. thank you! say hi to the fur crew from me and copperdog and i :-)

[@UncleDoug]

You're welcome, Giz. They are waving back as we speak :)

[@cawfeedawg]

Double Uncle doug fun! Thanks UD for all the work you do to keep these beauties alive and kicken

[@UncleDoug]

You're welcome, CD :) My pleasure.

[@Torgo63]

Great Video. Thanks for explaining the rationale behind the decision between leaving intact versus changing components, that's great insight to some of your repair decisions in prior videos.

[@UncleDoug]

Thanks, T. I am a purist. In my own amps I strongly favor the retention of original parts. However, as you noted from my soliloquy in the video, when dealing with long-distance customers, different judgement parameters are applied. I appreciate your understanding of this apparent dichotomy.

[@ronnieallred7888]

I watch for the electronics portions of your videos, but live for the awesome guitar solos at the end, Thanks Jack.

[@UncleDoug]

Thanks from both of us, Ronnie :)

[@ronnieallred7888]

Dear Uncle Doug, Been playing Rock Bass for 54 years, I'm 63, I have been looking for an Ampeg SVT 70's era (preferably later 70's) to go with a 8-10's cabinet I've owner since then, I had the whole rig (head & 2 Cabs, sold head & 1 cab when I wasn't working with them) now I'm sorry about that, just the heads are going for $1,800+, if you know of one please inform. But, I settled for & will soon be receiving an Ampeg V-4 bass head that works but has some issues, got it cheap, ,seller says it has a wire lose & didn't know where it goes, Haa maybe that's the problem ;-) I hope your tutorials have prepared me for this endeavor, I already have the schematics & will go through it completely so, I'll drain those caps & it's on! Thanks for all you do, I love your approach & all your animals. P.S: Rusty could really rock that six string!!! Thx, Ronnie Allred

[@roberthurless4615]

I think it is a testament to the build quality of those old transformers that they could take that kind of abuse for all those years and still function.

[@UncleDoug]

I agree. They must have been overbuilt to last so long.

[@bobbys4327]

I build a 6G2 "Brownie" from scratch a couple of years ago and I love it! Great video as always Uncle D.

[@UncleDoug]

Thanks, Bobby.

[@murratosmani6517]

Wow this Princeton is marvellous! Looks nearly as if it is fresh from the shop! Can't believe it's from 1961 7 years older than me and looks far better:)

[@UncleDoug]

Thanks, Murrat. I'll bet your skin is a lot smoother, however :)

[@schance1666]

Thank you for filling in that most vacant of silhouettes on the family tree - the genius uncle whom we bug to death as a kid because he takes the time to teach us fascinating things!

[@UncleDoug]

That's a vacancy we will gladly fill, SF......other than the "genius" part :)

[@boboala1]

Uncle Doug...I think you're funny! Uncle Doug...I think I love you for educating me and having compassion for stray beasts - Hi Casey! Uncle Doug...I think you been in the woodshed...was that ZZ 'Have Mercy' at 32:15? Yes it was! Sounded good...I'm proud of ya! Great repair tutorial & Texas licks...cain't beat that!

[@UncleDoug]

Thanks so much, Bob. We really appreciate the nice comments :)

[@richardweinberger2756]

For those who complain about affordable amp deals, in the L.A. CL 3 nights ago there was a "67 Princeton Reverb that sounded great but the reverb was flaky - needs restoring. $400". It was gone by the following morning - duh !! I usually pay about $100 for a fun tube amp in working or near working condition, so even at $400 this was rich for my blood. I got a gorgeous Bogen DB20 hifi amp 2 days ago for - yup- $100 - all Amperex Holland preamps and lovely Sylvania power tubes too. Sounds wonderful :) Happy New Year Doug !!

[@UncleDoug]

Yes, but that same PR, refurbished and fully operational would at least quadruple your investment, Richard. You can't beat old Fenders for resale value. Nice old PA's are significantly undervalued, however, and make wonderful conversion amps.

[@richardweinberger2756]

@@UncleDoug Doug, I live in a so-so neighborhood and have had nice items vanish and gone forever, including a handgun. Any "real" Fender amp would make me a target for theft and I would prefer to stay with weird stuff that nobody would try to pawn. I'm sure that somebody is loving that Princeton right now.

[@Wildman9]

Wow,what a great surprise with the Double Down repairs,and with our fav.paint sprinkles.Great sounding amps of my youth.Keep up the great work Uncle Doug.👍🎸🔌✌

[@UncleDoug]

Thanks, Bob. We will :)

[@bobwferguson]

Thank you cause I’m learning how these things work I’ve been using tube amps over the last 50 years

[@UncleDoug]

You're welcome, Bob.

[@jlucasound]

Not to put down Doug's playing abilities, it was a good thing to get a more "Modern" demo in play. It worked. You are great, Uncle Doug. You know more than most. Myself included.

[@UncleDoug]

Thanks so much, JL. We aim to please :)

[@bullthrush]

I kept expecting masking tape on the speaker or something on the Princeton, what a beauty! The champ came out good as well. Thanks for the glue tip.

[@UncleDoug]

Thanks, Andrew. You're welcome.

[@edwardhannigan6324]

Hey Doug, I'm still wandering around your channel, gleaning as much knowledge as possible. Great repairs and choice made on whether or not to preserve those old caps. They would probably fail soon enough. Thanks for sharing..Top stuff..Ed..U.K..😀

[@UncleDoug]

Thanks so much, Ed. It's always good to hear from you.

[@chaimatepimolviriyachart1560]

Great work and very details! Thank you so much for sharing Uncle Doug!

[@hi-friaudioman]

Man, that brown face fender is in pristine condition! Such a gem! Thanks!

[@UncleDoug]

It is indeed, 7th. You're welcome :)

[@hpelisr]

Great job, Doug. That little champ is kicking,you can send that one to me. Well done.

[@UncleDoug]

Thanks, Hack :)

[@Modwiz125]

Your diagnostic skills are great, Uncle Doug. Something I wish to continue to learn and emulate when I finally begin my first amp build at the tender age of 66. Having watched every one of your amp based videos, so many concepts have arisen that I do wish to try out. If only you were available for consultation, my learning would advance greatly. I'll keep watching your output and perhaps my questions will get answered that way. Thank you very much for what you do.

[@UncleDoug]

Thanks, Mod. I think you'll find that once you get started on a project, things generally fall into place......and any problems that do arise can be solved by experimentation. For those that can't......I'll be here to answer questions. Good luck.

[@BadChizzle]

The screen is just to shield out the 60hz and simply caps off the top of the chassis. All open wiring inside makes that very helpful. I’m sure it was very cheap to procure. Prolly works as well as foil. Man... that amp is a beauty! I always get excited when you’re gonna open something like this up. Bam... I was not disappointed!!!

[@UncleDoug]

Thanks, BC......glad you liked it :)

[@sam127001]

Thank you for sharing your knowledge , techniques and experience with us !

[@UncleDoug]

You're welcome, Sam :)

[@dhix2388]

GREAT SOUND. got the Ventures tunes all over it. THANKS.

[@UncleDoug]

Wow......Thanks, DH :)

[@lindseytackett3098]

I had a brown face Princeton in the 70s when I was in high school, still kicking myself, replaced with a Sunn 200s. Still have the Sunn.

[@UncleDoug]

We've all made mistakes in our wanton youth, Lindsey.

[@docdevin1]

Just a quick note on the metal screen in the top and the radio transmissions. You mentioned Mexican radio stations and ironically I can recall in March of 1986 driving on the way back from the Guadalajara, Mexico area and in the evening, while still not far from there, picking up KOMA, 1520, out of Oklahoma City, Oklahoma. Roughly 1300 miles. I am from Oklahoma so I immediately recognized the DJ. It was a 100,000 watt AM station back in the day. I also remember being on wheat harvest in 1980 and out in the middle of no where and catching some other stations from many states away.

[@UncleDoug]

I used to listen to KOMA late at night also, Doc, and I am in West Texas.

[@Starcrunch72]

This is so neat and the timing is great as I have a blackface princeton that was brought to me just last week that I have not opened up just yet--also having poor tremolo performance. However, looking inside the bottom of the amp, the tube chart was almost completely gone and the filter cap can has previously been replaced with a CE unit. I plan on filming so we can all see what happened to it. I am certain my video and voice-over will not be as thorough as you-but I'll try.

[@UncleDoug]

Thanks for your kind comments, SC, and best of luck with your video. About the only thing that can go wrong with a simple trem circuit like this is either the oscillation loop caps, oscillator tube, or problems in the bias supply (in circuits such as the Princeton).

[@Starcrunch72]

@@UncleDoug Yes I will check those out. When the customer dropped off the amp, while he was here, we fired it up, wiggled the 12ax7 and the tremolo kind of started to work..so we discussed possible tube replacement, but definitely socket cleaning and pin fitment investigation. I also said I'd check voltages and resistance down through the amp. I'll get started on it this afternoon...video to come.

[@UncleDoug]

We look forward to it, SC. Best of luck.

[@kjatexas3679]

The Silverface Champ is a great amp. I have a '73. I replaced the original Oxford speaker, with a Weber also.

[@davecheney8501]

Uncle Doug, Thank you for these great videos. I am a recent subscriber so I get to feed my addiction for your content by going through your older videos. Thank you once again, I am learning so much and being entertained at the same time. That princeton is amazing and sounded so well balanced. 👍

[@UncleDoug]

You're welcome, Dave. We hope you get the chance to enjoy all our videos.

[@CH_Pechiar]

Great video. Regarding the princeton tremolo caps, I believe that it was the leakeage in the caps that made the tremolo behave that way and not the capacitance. In fact, if the caps have leakeage it will give a false reading in most cap meters, and, contrary to what would be intuitive, they give a higher value than real. If you think of it, in an RC circuit that measures the time to reach a certain voltaje, technique used in many cap meters, if you put a resistor in parallel with the cap it'll take more time to reach the voltaje, thus reporting a higher C value than real. That's why it's missleading to only read capacitance of a capacitor to check if it is ok. In my opinion you took the correct path of replacing all of them.

[@UncleDoug]

Thank you, Charlie. I have other ways to test for coupling cap leakage.....but even if they don't seem to be leaking at the moment, ancient coupling caps are going to break down eventually (probably fairly soon if the amp is going to be used a lot), and it only makes practical and economic sense to replace them.

[@bobboitt3126]

That little Champ sounded great when you finished!

[@UncleDoug]

Thanks, Bob.

[@djgaryowens]

Very well done yet again.

[@UncleDoug]

Thanks, Gary.

[@djgaryowens]

Before Christmas I rescued a PA system that was gathering dust and been unused for years from a cubby hole underneath a pubs stairs. It was a QSC power amp And a pair of Yorkville speakers. Nothing electrical was wrong with anything they were just very dusty and dirty I just took the stuff apart, cleaned it and put it back together again. The QSC amp is probably 25 or more years old but this thing was sure built to last you can tell by the weight of the transformer inside and it will be good for quite a few years yet it really kicks out the Yorkville 15 inch speakers sound great the system has gone to a guy who plays techno music. Horrible yes but it is nice to get old school stuff up and running again.

[@tomk1tl]

HI Doug....I built a Fender 5F2A circuit a year ago and also had to increase the bias resistor to 1KΩ and the bias cap to 100V (over kill, I know). I also replaced the 12AX7A with a 5755 (tube wiring different but same characteristics) and is quieter. I always enjoy your videos and glad that KC is doing fine and looks great. She will be glad to get rid of her "bonnet" !

[@UncleDoug]

Yes, the original 6V6 bias is often absurdly high, Tom. KC is running around quite happily today, finally free of the awful collar.

[@blackdogbite]

Oh very nice! Quite a set that Jack and Ollie did on the Princeton! ZZ....Credence.....

[@UncleDoug]

Glad you liked it, BDB.

[@roncarter2188]

Have Mercy, The Hollies would be pleased, job well done!

[@UncleDoug]

High praise indeed, Ron. Thanks !!!

[@benlogan430]

The brown faced fender is serial numbered starting with POO! Nice!

[@UncleDoug]

It makes sense in a perverse way ;)

[@blueseruser]

Watched the do over on the Princeton..... Sounds great, and pretty swampy, Fogarty like.... Your cats have mad axe skills!

[@UncleDoug]

They are available on Ebay. That's where I got mine.

[@blueseruser]

Uncle Doug , Thanks for the reply.. I looked there too, but there are so many. Didnt see any exactly like yours.. if you have time, send a link to ones like yours, Thanks, luv your vids!

[@UncleDoug]

@@blueseruser www.ebay.com/itm/Banana-Plug-to-Test-Hook-Clip-Probe-Cables-for-Multimeter-US-Stock/111251407908

[@blueseruser]

Uncle Doug , Thanks for the reply, am ordering today! In awe of your broad electronics knowledge and help!

[@brianm9282]

I use 2 yoga blocks to hold up amp chassis, well my blackface bandmaster chassis as that's the only amp I've worked on so far. But I'm learning so much everyday.

[@UncleDoug]

That's a clever idea, Brian. Keep up the good work :)

[@tmitz73]

Great Video Uncle Doug!

[@UncleDoug]

Thanks, T :)

[@efenderbls]

What a perfect day off I have today and a new video by Uncle Doug beautiful amp awesome work and great attention to all the details that are in need.

[@UncleDoug]

Thanks, Eric. We hope your enjoy your day off :)

[@davidbolus]

Nice work! Amazingly I recently picked up an original single owner Brownface Princeton for my son. Same great condition. Very unique and beautiful sounding amp...

[@UncleDoug]

Thanks, DB. Your son is a lucky guy.

[@jasonkirkham550]

So glad to see another Uncle Doug video. And as usual; I learned something.

[@UncleDoug]

That's what we're here for, Jason. Glad to hear it :)

[@lamppostwillie]

Wow, love that Princeton! I recall agonizing over the purchase of a perfect brown Deluxe in a pawnshop in the 80's. It was an outrageous $300, so I passed. Oh, hindsight...

[@UncleDoug]

Thanks, William. Amen on the hindsight :)

[@williamsquires3070]

Actually, I’m just here for Jack! 😻 The electronics repair is just frosting on the cake!

[@UncleDoug]

He'll definitely make an appearance in the next video, Bill :)

[@sgtrutters5892]

I love my brownface princeton! Mine isn't in as nice condition outside, as it appears someone's small child found a sharpie and colored on the top. The inside is very clean though. It may need to be serviced at some point in the near future though! Thanks for sharing!

[@UncleDoug]

You're welcome, Matt. BF PR's are uncommon and wonderful. You're a lucky guy :)

[@instructormaint8423]

@41:35 in a few seconds KC speaks up in agreement. What a shop cat.

[@UncleDoug]

She is a sweetheart. We enjoy having her in the house full time now :)

[@tom7601]

"The mighty 1090, X-E-R-B! Dis is da Wolfman Jack Show!"

[@UncleDoug]

Yep......cruising around in the old 1955 Chevy (283 bored .060" over with 4-speed and 4.11 Positraction) late on a summer Saturday night, listening to "Blues in G" on the Wolfman show.

[@sweettoof9002]

That Princeton looks New Old Stock. What a sweet amp.

[@UncleDoug]

It was a beauty :)

[@steelcity321pb6]

Two amplifier restoration projects for the price of one: you’re spoiling us Douglas ...we could get used to this LOL. I agree, those old paper, and foil capacitors look good, especially when compared to the new dull looking yellow types but due to the nature of how paper ages, they have to go! Two excellent repair projects that held my interest: thank you my friend. Regards, Phil.

[@UncleDoug]

You're welcome, Phil. Thanks so much for your nice comments.

[@skycarl]

Now those two amps were a real treat. Thanks gang.

[@UncleDoug]

You're welcome, Carl.

[@jlucasound]

HS. My eyes went two sizes bigger when you unveiled that amp. I didn't read the Header. Nice surprise.

[@UncleDoug]

Thanks, JL. It was quite a gem :)

[@rickya3877]

Great vid...re-kicking myself for passing up the exact Princeton 15 years ago at Sam Ash 😫

[@UncleDoug]

Thanks, Ricky. We've all done it :)

[@tmitz73]

Awesome Video Uncle D!!!

[@justinbouchard]

The white paint bit always kills me :)

[@UncleDoug]

It's ubiquitous !!!!

[@ThePreyMantas]

LOL :) Jack & Olly remind me of Wilson on Tool Time, but never see these guys. Come to think of it we never see you either! LOL

[@UncleDoug]

Maybe we're all just figments of your imagination, PM ;)

[@eggy68]

Beauty! That Champ breaks up nicely.

[@UncleDoug]

Thanks, Eg.

[@PorchBass]

What a lovely pair of coconuts! Thanks for the excellent video.

[@UncleDoug]

A great tune, especially when sung by Mae West, James ;) You're welcome.

[@sinnerG7]

Another informative and fun watch U.D.! Anyone else wonder what U.D. looks like? for some reason Stan Lee comes to mind for me

[@UncleDoug]

Thanks, Sinner. I can speak with authority that he looks much like a cross between Tom Selleck and Jason Momoa.

[@senorcapitandiogenes2068]

And kind of "Double header" is sure to bring pleasure into your life

[@UncleDoug]

Now, now, Capt. D, this is a family channel :)

[@jasonkirkham550]

Best double header yet !

[@UncleDoug]

Thanks, Jason :)

[@redjetfirebird]

Oh man! This is gonna be good! Two of my favorite amps of all time!

[@UncleDoug]

I hope you enjoy it, RJ. They are really nice amps.

[@redjetfirebird]

@@UncleDoug as does everything you touch (or at least release videos of) HAHA. Thanks again for entertainment as I work today.

[@UncleDoug]

@@redjetfirebird You're right. The abject failure videos are never posted ;)