Thanks, Ken. It's a real pleasure to work on really fine, original equipment like this. It's also a great way to see firsthand exactly how they came from the factory......as a reference for restoration of lesser amps.
Thanks, Henry. It was so nice that I had to share it with the YT audience. It has since gone home with its owner, who seemed very pleased with the repaired tremolo and overall tone.
2019. Having breakfast and watching this art. I’d love to see you take photos of the internals, frame them, and sell them. I don’t know a single person who wouldn’t buy one. Great work!
I was very fortunate to have recently come across a 66 Princeton Reverb that I bought from its one and only owner. Your video was very helpful in dating and inspecting the originality of my amp. Thank you!
+John Cunningham It really is a nice one, John. The current owner bought it and an equally mint Fender Mustang guitar from the original owner's son. I was very envious :)
Thank you, Uncle Doug!! Your thoughtful in depth videos have helped me countless times understanding tube amplifiers and has propelled me to suscessfully build my first clone amp, the Vibroverb 6G16.
Outstanding- it actually sounds like I am back in the 60's listening to oldy goldy from the 50's ,you know while back in the 60's not in the 2010's doesn't even sound right.
I got to borrow one of these gems for a few months back around 1975. not sure of the year but I was told it was a late 60's vintage. We covered the Who's version of Summertime blues. I had read in the Rolling stone that Pete Townsend used a Ric and Princeton Reverb for S.B.s ( turned all the way up with no pedals....just the amp). I still had the 330 so I cranked every thing up to 10. Nailed that tone!! :-)
Thanks Uncle Doug, very kind of you to share this gorgeous amp. I love the way we tech's play through such fine amps)) I think the CBS label also gave the age away. Cheers Michael
Wow, outstanding video! Thanks very much for taking the time to share this incredible find with the world. Your customer was probably more than delighted with your work.
like going back in time in a time machine, astonishing. So someone from 1967 or thereabouts bought this amp for $100(?) and put it away in a closet with the leather cover on it and we just uncover it now. That’s crazy. Love it.
Uncle Doug I don’t think I’ve ever seen one like that. There’s probably not many left like this. Maybe it could be in a museum. Didn’t replace the two prong plug?
That is a sweet amp. I was able to find a 1966 Princeton in the same condition. It does not have reverb but the shimmering tone is killer. The only mod I made on mine, which I am surprised you did not make, is to replace the two conductor power cord with a grounded power cord. I just take the original parts, bag them and place the bag in the back of the amp for safe keeping. Makes the amp dead quiet and safe. Thanks for showing us this amp. It is a treasure.
Bill Norman Thanks so much, Bill. Please note that this is not my amplifier, but one that I was repairing for a friend. He's a stickler for originality, so the two-wire cord (which was in excellent shape) was retained.
im actually rebuilding a broken silver vibro champ into a black champ as im watching your vid. i watch your vids alot when im working. Im way into amps and way into rescuing dogs so i dig your and your dogs vids alot
This is the kind of find that usually come with some sort of tragic story about the original owner. 'Original owner dies or is killed, and the amp stays in storage for ever more.' It's an amazing find. Trouble is' that if you bought something like this, you'd feel some sort of serious responsibility to keep it this way - so it again becomes a home amp and never gigs!
You're right, Chris. In this particular case (the amp belongs to a friend/customer) it was indeed purchased new, along with a Fender Mustang guitar, by a young fellow who simply lost interest and stored them in the proverbial closet until four or five years ago, whereupon he was coaxed and coerced into selling both to my friend. The guitar was equally spectacular, but sold on Ebay before I could make a video of it. As you predicted, the amp is displayed and only used occasionally at the owner's home. As with classic and "survivor" cars, some things are cursed by being so nice that their extraordinary condition discourages use. Thanks for your input :)
Sad really! It was never meant to be in a museum, but to be heard. I hope he starts playing it a lot and if we are lucky others will hear the beauty in a sound that is just perfect to describe. P.S. Love your channel!!!
Uncle Doug-Just because we don’t see Rusty in the video doesn’t mean he hasn’t been busy behind the scenes taking care of all manner of binniss. I sometimes wonder if it hadn’t been for Rusty if there even would have been a Fender Princeton Reverb in the first place! Whether in front of, or behind the camera, his presence is felt at every level. What a legacy he left us!
Thanks so much, Frank. David and I appreciate your kind appraisal. I wonder how a potentiometer would work, instead of the rotary selector with finite resistors? It would be like a "Master Intensity" control, with the regular intensity control merely serving to fine tune the depth of effect. This might be an interesting new feature, especially for "Tremolo Hounds" (like me).
these and the champ tweeds of the 50s represent a very well equipped tone package. That the deluxe have more tubes than the champ series of the early 50s has made it easy for me to hear the type of tweed amp I wish to pursue. The ones with more than three tubes and those with only three tubes. I have come to understand after this demonstration, that I should also consider the filter choke or lack of and the differences in the use of capacitors through the different year models and the different tube models all make for more consideration towards tweed amps in my epic search. Thanks again Uncle doug for the wonderful efforts to inform the guitarists masses in the way of intricate and delicate observations on the multitude of amps you presented and present on you tube. Its worth the viewing and the opportunity to learn from a gifted technical advisor.
Uncle Doug May the force be with you Uncle Doug! I've learned a lot from your videos. I recently graduated from a a community college and earned a 2 year diploma in Electrical/Electronic Engineering, and two certificates in Industrial Electrical Principles and Industrial Electrical Principles. College and your videos has vastly improved my knowledge of electronics, and Amplification, but I still have many, many more things to learn.
We never quit learning, OO, and it appears that you have done quite a bit of it in the past few years. I'm glad our videos played a part in that, and wish you the best for the future.
mine had a different speaker also. i had a very clean 65 non reverb. the 65 non had a smaller watt speaker which i think sounds better. when they added reverb which i think was 66 they went with a slightly bigger wattage speaker. the 65 non was my all time favorite small amp. my 63 ss rectifier with presence bassman may have been my favorite all time amp. i had 30 vintage fenders in my young 20's then i got into heroin which turned into 200 dollar a day habbit. bye bye fenders. iknocked off the heroin and i know howto build amps so im good for live use but sometime i miss my wall of fenders.
What a great little amp. And another cool vid, Doug. I liked how you made sure the amp needed to come apart. That's Aretha singing "Respect" in the background. I have a CyberTwin with a zillion models and such (Its still a good amp). Sometimes wish i could just blast a Princeton here at home
Hi Doug,Thanks so much for your amazing videos. So sorry to hear that your esteemed canine co-star passed on. May he rest in peace.I was watching your vid about the Mint Blackface Princeton last night. Very envious that you get to work with such a beautiful amp! In this vid you isolated the biasing diode as the cause of the problem with the tremolo system. Could problem with the diode also explain the distortion at 9:50 when you were testing the amp at vol 5, no reverb or trem. I'm thinking that the diode might be letting through some AC from the bias tap. Apologies if this is a silly question! I am quite new to this world of valve technology.
Greetings, Tom, and thanks for your very kind and thoughtful comments. You have an excellent point.....one that I should have mentioned in the video. Anything that reduces the -DC biasing voltage would increase the tube bias and cause the early breakup that we hear in the video. It would have been interesting to check the tube bias (plate dissipation) with the failed diode in place......I'll bet they were on the verge of red-plating. Thanks for bringing this to our attention.
I'm not a big tube amp guy (my solid state KMD GS150D suits most of my needs wonderfully). However, I did just acquire a Super Champ XD which has piqued my interest in the older amps it tries to simulate and found this video. This was a thrill to watch. Thank you.
I have an all orig Blackface '65 P Rvb (Fender electric instrument panel). Use it all the time. Has an Oxford Spkr that's marginal, but I run the cable into Dlx Rvb that has a Jensen P12N RI installed. Great sound & def a keeper...!
Question for you Doug: On my '65 BFPR, while it's a real gem & I believe unscathed by human hands, save for the 3-prong cord...everything works as should. The only thing that seems odd, is the Treble control. I have it set on Zero (vol 3/bass 4/rvb 3) & still seems bright to my aging ears. Or, Is this normal? I play a Strat w/ Rio Grande pups along with other Strats w/ the addtion of a Klon Centaur pedal (sometimes). Rio's are not inherently bright pickups, nor are Van Zandt pups. Any ideas on how to tame the brightness in the amp? I'm not very savy on amp electonix & my amp guy is no longer with us... Tubes: V1 - Tung-Sol 12Ax7 V2 - Phillips 12AT7WC V3&4 - Tung-Sol 12Ax7 V5&6 - GE 6V6GT Rectifier - Bugle Boy GZ34 ? (can't read numbers)
Interesting little video! I remember doing a modification on a beat up Princeton Reverb amp once where I installed a rotary selector switch to switch added resistors in or out of the circuit so the customer had more control over the degree of tremolo...I mounted the switch in the chassis so it was reachable through the opening in the back cover...it was a quick idea to give the client what he wanted :) You & David have the best videos on YT From one tech to another, keep up the good work :)
JZ, since this amp has a power (isolation) transformer and properly fused power circuit, it actually is quite safe as it is. When amps like this have flawless original power cords and plugs, there is (IMHO) no real need to convert them to three-wire cords. If the original 2-wire power cord was damaged and required replacement, however, I would install a 3-wire cord. Also, IMHO, if properly done, installation of a 3-wire cord does not detract from the value of an old amp.
Very impressive, someone really took care of his gear... I was, umm... made in '67 and born in '68, and I wonder if I'd look as good if I took as good care of myself ;) I still have all the original parts, but the wear and tear is easily visible ;) It's great that you had an opportunity to document every detail of this amp for reference. Not that I really need it, I'd have to be extremely lucky to get hold of one at a sensible cost. Back in the 60's and 70's in Poland (where I live), during the communist times, almost nobody could afford original foreign gear like this... And if one did, it were usually the British products. So my options of finding one locally are rather limited. But I can feast my eyes on it thanks to you :) Best regards, Stan
Greetings, Stan. I was indeed fortunate to be able to document this wonderfully original amplifier. Hopefully this documentation will assist others (and myself) in the restoration of more typical, highly used and altered, units. Blackface PR's in any condition are relatively scarce and expensive, even in the U.S., so I can only imagine how exceedingly rare they must be in Europe. As always, thanks for your interest and input :)
We are setting up a studio and are in the process of buying the equipment. We have secured a mint 65 Vibrolux reverb, and a mint 67 Vibro Champ, can you guess the one we are still missing?
I need to video and photo my vibrolux reverb.. same year, just as mint, minus the tag. Im second owner, bought in 1968. I also have the cover, largely responsible for keeping it nice.. I love these blackface amps
I just subscribed. Awesome stuff. Love the Fender amp repairs. Thank's for sharing you vast knowledge on electronic repair's. Please put your dog in more. Was his name Rusty? Anywho He seems to know his stuff. Great by your side also. Thank's for the great video's.
Beautiful Amp!! I'm not sure if you're aware of this shortcut or not, but the absolute fastest way to date a Fender amp from 1951 until 1969 is the ink stamped code on tube chart. In this case, it is QF. The first letter is the year, and the second is the month of the year. You start with "A" for 1951, and count up the alphabet from there. The same goes for the month of the year. So here we go, QF = 1967/JUNE. These were one of the final codes stamped on vintage Fender amps and most accurately dates the amp. I've never paid attention to the chassis serial numbers as they tend to wander very far from the actual production date. If the tube chart is missing, I use the speaker codes and transformer codes. At last resort, I use the date codes on the pots. I have two PR's, a '66 and a '68 first year silver. I've collected Fender amps for nearly 25 years and aside from the 5F6-A late 50s 4x10 tweed bassman, the PR has been my all time favorite Fender amp. In my opinion, they beat every other blackface model when it comes to pure vintage Fender tube tone...Leo really nailed with the PR and the 4x10 Bassman.
Thanks for the excellent comment, PG. Yes, I was aware of the Tube Chart dating system, but neglected to mention it in the case of this amp. It belongs to a friend of mine who swore it was a '65, but it became quite evident as I began to make the video, that it was actually from mid-1967. This put me in somewhat of a bad spot, since being accurate in the video required that I contradict the individual who allowed me to use the amp in the first place. I totally agree with your preference for the PR. I have a '66 and a '67 (both featured in videos on my channel), and if the house ever caught fire (God forbid) they would probably be the first things I would carry out the door.....please don't tell my wife or my cat :)))
It may be covered somewhere below...but surprised you did not do a complete deoxit of pots and switches when fully accessible to reduce future corrosion. Excellent video patiently covering details.
I am anxious to see your video and would be glad to offer any assistance that I can. I do not have personal experience with these two specific amps, but that is not a huge issue since virtually all early Fender amps are quite similar in design.
I have a '67 PR and found that same diode was bad after I couldn't get a stable bias current reading. I put the scope on the 6V6 grid pins and found horrendous random supersonic noise that traced back to the diode and its associated circuit. After replacing the diode, cap, and both resistors on that board (and juggling resistor value for proper bias) the tremolo came back with a vengeance! It had been completely dead for years and replacing the trem capacitors only brought it back a tiny bit. Now it's better than it was when I acquired it almost new. The trem relies on correct bias to work right, changing power tubes without rebiasing can make the tremolo weak or kill it altogether, and that has bad implications for the tubes too if it's that far off.
Excellent work, PH. Many people faced with weak tremolo focus entirely on the trem circuit, particularly the three caps in the oscillator loop, and completely overlook the somewhat clandestine effect of the bias voltage diode. Hopefully the video and your excellent explanation will clarify this repair technique for the viewers. Thanks so much for your helpful input.
I have got you beat. I have a 1967 Fender Princeton Reverb that is absolutely pristine and 100% unmolested original. Still has the born with RCA tubes, reverb tank, speaker, speaker cable... to boot, my tremolo still works flawlessly. I'd bet that I have the finest example of this amplifier on the planet. Mint condition.
Uncle Doug, no you've got me on that one. I am also missing the original footswitch. But my amplifier is what I'd call pristine for a 54 year old amplifier. The one in your video is pretty awesome though. You've got me smoked on your knowledge of repair my friend. I aquired mine from a gentleman who's uncle bought it new in 1967. It's been put away in a closet for the last nearly 40 years. Thank you sir for taking time to show and tell the 67' Princeton Reverb.
Awesome, man! I've got a 66' Princeton and its basically my main amp. While mine is truly "road worn" as they say, it just blows ALL other amps in its range -and some out of its range- totally away! I just posted a little video, showcasing the amp and some killer guitars, too. P.S. I've heard ppl call these Princeton's the Holy Grail of tone. I think it may be true.
super champs are the immediate accessible amp that would bring my ear to a happy place. That the amps are less than 20 watts in most cases pleases me tremendously. I do not want a blues deluxe in place of the original low wattage champs I m pleased that fender does not limit tweed production in the modern era. Though I would be pleased if they did a reissue of the original tweeds of the early 50s to include the wide range of tone monsters like those of the 50s....from the bassman and back to the 48 first issue runs of the lap steel and harmonica/guitar tweeds. They all are a blessing, but no so much as to only allow for limited issues from time to time.
A closet queen no doubt. With the optional amp cover, it is not showing it's age unlike a lot of amps of that period. The diode that failed is providing a negative voltage to the 250k intensity control of 1/2 of the 12ax7 oscillator. The plate of the oscillator is connected to B+ 240volts. The feedback bias through the intensity control forms a LFO. low freq oscillator. Definitely..a very nice sounding amp.
Add a bias pot and you'll be able to dial in proper plate current, and, voila! The sweet spot on the vol dial just got sweeter. That's been my experience. My 65 Deluxe Reverb built from a kit with some of my own tweaking is "bias critical" for the best tone.
Greetings, MM. I couldn't add a bias pot to this amp, since it belonged to a customer, but I have added them to my own PR's. It's a rather simple and rewarding improvement. Thanks for your input :)
The diode you replaced is used for the negative bias voltage supply on both output tubes grid. Both 6V6s may have also been red plating. BTW Very nice amp and interesting video.
Awesome. This was so enjoyable to watch. It's my Favorite Amp of all time. I just purchased the 65 Reissue. (and I love it). There's nothing like that pristine Fender glassy-chime with my Vintage Strat & the Spring Reverb. I once had an Original Silverface Princeton. Question Sir: Is it possible to "Slow-Down" the Vibrato/Tremolo Speed on my new 65 Reissue? I have it on 1 . . . and its still faster then I prefer. oNe LovE from NYC
Thanks, Michael. You can slow it down by increasing the values of one or more caps in the oscillation loop. The best way to do this is to experiment by adding additional caps in parallel to the existing cap(s), while the tremolo is running with speed set to slow as possible. For instance, if your loop is .01, .02, .02 then change the .01 to .02 and see if you like it that way. If it's still too fast, clip in a .01 parallel to any of the .02's making it .03, etc. etc. until you get it as slow and swampy as you like.
O.M.G. Thank you so much for your prompt and informative reply. Unfortunately I am not technical enough to do it, so I will have to bring it in to a Respectable Amp Tech to do this for me. Its Brand New - so I am going to wait-a-little on this, ( but I will save your valuable information ). You really know your stuff. If I lived closer to you . . . I'd Trust ( and gladly pay ) You to do it for me. Thanks Again.
Goes without saying that the original blackface Princeton that you demonstrate here in this fine video demolishes all pricey modern boutique clones I've encountered. Like the Rock and Roll music played on it, the Princeton is superficially simple yet devastatingly difficult to get right.
back in the day factories made or ordered parts in batches and kept them on hand,unlike today's "just in time arrive on the day of production" method that is common today.....sometimes a year newer part was used on a product simply because it was where the employee could reach it....i had a sixty nine p base with a factory 70 neck,and that's what i found out at the time....
Amazing find. I'm very surprised a diode failed in an amp that got almost no use. Maybe it was a factory defect that never got serviced under warranty? I hope whoever owns the amp plays it occasionally. I know it's much too nice for gigs.
It's not that uncommon, Ray. I guess the original diodes were not of very high quality (?). I believe the owner sold the amp through one of those big vintage instrument auction houses.
+3gdosrsfs The Princeton is one of the best amps ever made, sadly however that makes them desirable to thieving slimeballs. I hope you find a good replacement some day :)
Uncle Doug .. I have a AB764 as well. I knew something was wrong with it by the sound but realized that the treble tone control was not working at all. In fact when you turn it all the way up...all the sounds goes off. Any idea what's going on with this? I love this amp.
songman68 Sometimes there is a bulge or extrusion of electrolyte from the center-base of can caps, but generally, you have to test the capacitors for electrical leakage.....which is invisible to the eye.
Just restored a 65 super reverb for someone at the guitar center ,had to replace 90% of the resistors all of the capacitors, values changed so much due to age not reliable the way it was . The parts will go bad ,change it all out it will sound like it did in 1965 and be reliable
DK I have a Fender Blues Jr. about two years old. Recently it started acting up. After being warmed up and then being pushed a bit hard with Master volume at 10 it begins to break up like a short somewhere. It will start as intermittent and then go to one constant roar at which point it is turned off. Can this be the output transformer going out. Is the a way to verify? Could it be something prior to the OT?
Long distance amp repair is simply guesswork, Don. It doesn't sound like an OPT....they are like a light bulb, either completely good or bad. Check the bias on your output tubes when the amp is warmed up, and if possible try replacing them with new tubes (if you have any handy). Occasionally tubes develop internal shorts when under stress.
Uncle Doug. I own a 1961 Fender Vibrasonic with the 15 inch JBL. I bought it new when I was in high school, I'm now 75. The amp is MINT. I'd really like someone with you skills to go over this piece if Fender history. Where is your shop?
I'm not sure what sticker you're referring to, Tom, but I suspect it is the power consumption: 120VAC x 1.65A = 200W. It's standard procedure for electronic gear to have its power consumption stated.
+Sid Fernandez It's not so much the tubes that are currently used, although they probably do affect the tone somewhat, but more the changes that have been made to the circuit, including solid state rectification, that differentiate the reissue from the original. If you want original tone, your best bet is to find a nice early 70's silverface Princeton, probably for less money than the original. The circuit is virtually identical to the high-dollar blackface version.
hello uncle Doug, I hope everything is going well ? I need a little bit of advice hear, a strange thing occurs on mij Princeton reverb amp. on higher volumes, about 6, a cracking noise is added to the sound. I've done some research and found that the reverb tank causes the problem. Even when, only the input jack is connected, the noise pops up. The whole electronic is brand new as the tubes to. Strange thing is everything works very good unless on higher volumes. The reverb tank has an impedance of 1,5 ohm. I haven't got a clue
+BAMPSANDPEDALS I can't diagnose issues like this without personally seeing and testing the amp, B&P. Is this a Fender Re-issue tube amp? If so, I have never heard of a Fender reverb tank with an impedance of only 1.5 ohms. If it's new, I would suggest taking back to where you bought it and seeking repair under warranty. Good luck.
I'm still kicking myself for not buying a mint condition 1967 BF Deluxe (with original cover)that a guy was selling locally for $3200 (Canadian) I kept thinking about buying and a day went by and I thought about it again and then boom! someone snapped it up. He who hesitates is lost.
I know I'm a few years late and I really enjoyed your video but am a bit confused about all the dates attributed to this amp. Under the on (red) lamp it clearly says that the design & circuits were Patented in 1968. Any comments? Thank you.
I have a 1965 pre CBS Fender Princeton that had been cut down to a head. Interesting, they made the head taller than normal. In fact you can still see the top of the speaker cut out. The amp was given to me in 1987 by a Scientologist in my apartment complex. I know he was grooming me a little, but being in Hollywood, skillfully fending off weird religions is in our blood. Nice guy though.
i think that was my amp. i bought it from a mexican who brother had it in the closet since new. oh nevermind my trem works and mine had all the paper work. also my cloth had more shine.i have the picsit had all paper work also. it sold for 3300 on ebay.
A question I was wondering about the other day - Is the reverb transformer in any danger with no tank or load attached? The tank in my 67 deluxe went bad and I'm running it without it until the replacement tank arrives. Thanks for any help. Love the videos!
Good question, Steve. I would say that no harm will occur, simply because the output of a 12AT7 is not enough to damage the transformer. To play it safe, however, pull the 12AT7 until the new tank arrives.
Nice. Not the kind of amp that was left in a dirty garage. I feel the love. Do you still feel the caracteristic subtle heartbeat rush when you've just discovered the culprit that was holding back such a fine piece of equipment from expressing it's full potential?
