Looks good and sound nice! In the late 70’s I’ve build my first tube amp from an old radio my father gave me. I used a transistor amp from an old recordplayer put it in front of the tube amp and it sounded amazing, like a Marshall, I remember my father being proud of me. I was about 14 years old. I’m still building my own amps and effect pedals and I’m still learning a lot by watching your video’s! Very inspiring too! Thanks👍
Uncle Doug...I am humbled to be able to experience the unbelievable patience you have to slow everything down, edit tape, explain, draw diagrams, entertain us with pet antics...I have modified, built, serviced, styled quite a few amps/pedals with high regard in my area...even fixed air conditioners, heaters, lamps, aviation headsets, stereos, wired entire garages with electricity you name it...all because you took the time to make these videos for us! Thank you for that, thank you so much for that. I sincerely hope that you continue to have the love in your heart to pass on the secrets of your trade to those of us who will keep the skill alive into the future....Each of these videos are going to be the documentation of the characteristics of each of these vintage amps as a library to the rest of us someday.... Having said that...as a musician...is there any way you can incorporate a higher decibel-level microphone in order to dial up the input gain to higher levels like around 5-7 (not cranked, I absolutely hate any person who uses the word "CRANKED" in any amp video title or description) so that we can actually hear more of the tonal effects of the entire system under a higher drive? I feel that every end-result testing at the conclusion of your videos with volumes at two tend to sound very similar with the amps you build/service and the system effect/impact on distortion/tone is not entirely communicated. I am a humble student. I hope you will consider my suggestion. Thank you for your time. Marlon
Thanks so much for your very kind and generous comments, Marlon. Rusty and I are quite pleased that our videos have enabled you to accomplish so much in the area of electronics repair. I fully understand your recommendations on how to improve the audio testing of amps and agree that my methods are definitely sub-optimal. My video camera does not allow for the use of a separate microphone, so each audio test is hampered by the limitations of my equipment (i.e. grain-of-rice-sized microphones). One of these days, I fully intend to invest in a better, more flexible, video camera that will allow for higher fidelity and volume recording. Meanwhile, thanks so much for watching, commenting, and offering good suggestions.
Outstanding job, I love the rear panels and way the sides/top/bottom wrap around part of the front to meet the groovy red grill. The red with black gator skin is perfect. Really nice layout and install of the electronics. Looks and sounds great. True craftsmanship.
I absolutely love you videos. They are very helpfull. I have a suggestion though. You have no reason to apologize for your guitar playing. My wife put it well to me one day. She told me that people who enjoy watching me play and sing would rather not hear my apologies. Your playing serves the purpose. It is very good compared to the majority of people standards. Apologies start sounding like excuses. To those that don't play as good as you it can be disheartening to them. Some wish they could play as good as you. You are a wise talented man and I hope that you take this as a compliment and advice from someone who has learned from his wife of 30 years. People are very apprecitative of me not whining anymore. Keep up the good work. Thank you for all you do.
Real music played from the soul is always good! John Lee wasn’t a technically great player but, he was one of the best players! It’s not how good you are but how good you are. Rock on! I like your playing!
I agree. Virtually all the speakers I have removed from organ tone cabinets have been Magnavox, code 232. I should have mentioned this in the video. Thanks for your input.
I love your take on the Woody! You're an artist... and I love that you share your thought process before you start to build. Adding "grid stoppers" and the Choke were also smart ideas. The Supro "24" (6424) uses the same Quasi "Long Tailed Pair" Phase Inverter. This is one of my favorite inverters because, if you voice it properly with the right coupling caps, it creates some gorgeous harmonics when pushed. The reason some of those old design caps sound so rich and unique, is because their tolerances are sloppy. When we look at today's tight tolerance caps, and apply the RC Time Constant Math and Frequency Calculations, we see a very precise Frequency Response and Tone behavior. When we insert a leaky loose tolerance cap... the frequency and tone response isn't quite so sharp and precise. You might say that they're softer. I've actually rolled my own tone caps before. You can also use some fancy frequency test gear and see the difference when you sweep them with an audio frequency. I think Leo opted for controlling tone for his guitars by selectively using gain stage coupling caps, instead of a complex control that steals the guitar's chime, and also relying on the guitar's volume and tone controls. Moving the tone control was a brilliant idea. The stock Woody is more of a Vox High-Cut approach, had it been a little closer to the phase inverter. Back then they weren't over-driving the front end with pedals. I've recently started a Supro 24 build that is using (4) EL34's for the finals. (EL84's would have also given the Woody a sweet grit.) I'm wrapping up the bias board and then it's time to fire her up. The Woody and the 24 are great brothers and sisters, but you need a little more oomph if you're going to gig a larger venue. The 34's should enhance the Quasi Inverter harmonics... I'm going for something Janis Joplin... a little raw and nasty... Thanks again for another history lesson!
The 15" speaker was also very smart... when you add, say a decent 12" to a Champ, the voice opens up like the heavens. Those small speakers choke an amp. I also love the semi-open backed cab that you built! A closed cab should be left for a bass rig. lol
Say... there's a great little hack that you can add to an amps power supply to silence the hum in place of a choke; although I prefer the choke like you used. (On a vintage restore, the added holes for the choke are frowned upon, whereas the added cap and resistor are harmless.) Add a 20uf to 80uf electrolytic cap right after the rectifier, and then a 100 ohm to 250 ohm 5 watt resistor, to strip off some 60 cycle noise before the B+ goes to the output transformer. This works great on a single-ended amp like the Champ, and the lower power push-pull rigs. So it's... power output tranny to rectifier to a 20uf to 80uf cap to ground (with a 220k safety bleed resistor in parallel with the cap to drain the cap when the power is off) to a 100 ohm to 250 ohm 5 watt resistor to the output transformer B+ (that also has at least a 16uf cap to ground) and then to the rest of your power supply resistors and filter caps. One other note... with the added cap, you want to use the smallest cap that will do the trick for you. Larger caps do put a strain on the power supply transformer. On Champs, I use a 20uf 500 volt cap with a 250 ohm resistor and they run whisper quiet. Again... the choke is a much better option if you can get away with it and an added filter cap will affect the "sag." I've also added a filter cap right after the rectifier and then a choke, and then the OT B+ with great results, too. Oh... and if you want to add a "standby switch," place it right after the 250 ohm 5 watt resistor and before the output transformer B+. You can also add a 100k 1/2 watt resistor across the standby switch to bleed a little voltage across the switch to keep the filter caps slightly charged in order to lower the current inrush when the switch is turned on and to prevent arcing.
Thanks for your nice comments and a great deal of informative, helpful information, Mark. Viewers like you definitely make the YT learning experience a two-way street. I am in complete agreement that much of the "vintage tone" associated with old amps.....and missing from the new ones.....is due to old, out-of-spec resistors and capacitors providing warm, imperfect, analog, harmonic-rich output that simply cannot be matched with precise metal-film resistors and high-dollar capacitors. To me old vs new is like a Rembrandt painting compared to an Etch-a-Sketch.
WOW! EIA code 513 was originally allocated to The Houston Transformer Company of Houston, Texas. Yes, of course, they did electrodynamic speaker and PM speaker voice coil winding, and even cast their own speaker motor parts too. I do not know if they stamped frames out or not, but they did smash stamp the motors' cast bosses onto the stamped metal frames. What a rare bird.
Thanks, John. Of all my home-built amps, this one turned out to be the best with regard to tone and power, and is one of my favorites. Yes, the old "virtual center tap" trick was once more employed to reduce hum (which is "virtually" non-existent) :)
wow, I could imagine the sound in person. wonderful, no need to apologize to Roy I am sure he is proud. he is my favorite singer /artist, I sing very much like him and many other people. just for fun. your work is out of this world man!!!!
Tis a thing of great beauty uncle doug ! showcasing your usual impeccable sense of taste in all things electronic and otherwise, for that matter😎 cool is ,,as cool does !
Thanks, Otter. Of all my scratch-builds, this is my favorite. As you say, the tone and silent operation (I added a filter choke plus some other updates) are exceptional.....and who would have expected it from such an early circuit design?
"...I'm a-walkin' in the rain, Tears are fallin' and I feel the pain, Wishin' you were here by me, To end this miz-zar-ee, An' I wonder"...,etc. And that amp is really Really beautiful... I'm surprised no one's approached you to market it... yeah, just stunning. Thanx Uncle Doug and... cheers
Hi Doug The 1946 Woodie Fender Pro used a 15” Field Coil Speaker. I still own the 1996 repro of that model from the fender custom shop for its 50th anniversary of Leo Fenders First amplifier. I haven’t been able to ops check it, I had some problems with it from day one blowing tubes. We corresponded about it but I haven’t been able to budget shipping it to you to restore it.
Thanks, Josef. The original circuit had the tone control after the 6V6's, but I moved it to a more conventional location after the pre-amp and before the phase inverter. I'm glad you like the tone.....it's one of my all-time favorite amps.
***** Thanks, Alva. I think point-to-point is the "purest form" of circuitry. The other methods are simply ways to facilitate mass production and minimize expensive, skilled hand labor.
Uncle Doug I agree. My preference is for turretbboards in my own amps, because I like the ease it provides in modifications, and I suspect components are the most secure with turret boards, but the beauty of point-to-point is hard to beat.
JZ, over the years I've accumulated lots of NOS brown, carbon resistors, but only use them when repairing a vintage circuit, so the replacement resistors match the old ones. In my scratch builds, I use metal-film resistors and occasionally, new carbon resistors of 1 watt (or higher) rating. I've heard that metal film resistors have a negative effect on "vintage" tone, but have never seen or heard any direct evidence of this being true. IMHO, their precision, longevity, and tone are superb.
Hi Uncle Doug , Nice build , your model 26 sounds great . I own 2 Model 26 Deluxes from May 1946 and they don't sound as nice as that one you've made . There's a couple of differences between the schematic you used and a real one , Mainly in the tone stack . Leo Fender used a very primitive tone stack for the "Woodie" Deluxe . He used a 0.05uf 600v capacitor that was fed through a 500kB pot between the 2 anodes of the 6V6 output tubes . the 3rd lug of the pot wasn't used . He also used a 300ohm resistor to bias the output tubes with a 10uf cap. and he had no resistor between the input jack on the Mic channel and the grid, it was just straight into the grid. The resistor from the Mic input jack to ground was 2 Meg and there was no resistor to ground on the Hi / low input of the instrument channel. (they had 3 inputs 1 x Mic , 2 x Inst). But the instrument channels two inputs were wired the same way later fenders were so you had a 6db difference between the two inputs ... I personally prefer plugging into the Mic inputs on mine , it sounds so much crisper and dynamic than the instrument channel .... I hope this information helps . I've sent Tommy the diagrams explaining all this , regards Mark
We're aware of the differences between the original schematic and my new, improved circuit, FAF. The changes were made to provide superior tone, component safety, and longevity......as you noticed. When cloning very early, primitive circuits, it's generally best to update them a bit with some more modern design technology. Thanks for your input.
Thank you for sharing the updated schematics! I'll try to build this amp (or maybe a bit modified) into an old-ish combo. Alas, the 6N7 is rare in the EU, so maybe a substitute will be needed. 6SL7 might be a bit stout, the 6SN7 a bit weak, but the latter might drive the output tubes enough to get close to the sound of the old Model 26 :)
Those loudspeakers were commonly used in Magnavox consoles of the day. Particularly the Magnavox Imperial/Concert Grand, I believe they are Jensen manufactured specifically for that purpose.
No problem. The hole in the center of the magnet was actually for a black plastic cap that would go over it in the sets. Here's one in it's natural habitat www.radiomuseum.org/images/radio/magnavox_co_fort/imperial_classic_1_st233_ch_6401_00_1523745.jpg. I work on a lot of these bi amp chassis so I always have a spare horn and woofer. Hard to not recognize them now!
232 is Magnavox, who made a lot of speakers and provided them for early radios and amps. That one is early, similar to a 40's Jensen magnet. Of course I am sure you know Peter Jensen designed speakers for Magnavox before he went out on his own. Anyway cheers Sir.
Even with the shortcomings of the camera mic, it still sounds very warm and round. The key (IMHO) is that it sounds warm/round AND clear with good note separation. For me, that's the perfect guitar tone. Thanks for sharing. Love the 15" speaker.
+quicklynamed You're welcome, QN, and I agree completely. The tone is exactly as you describe and I give much of the credit to the vintage 15" speaker. Thanks for watching :)
Oaktron speakers are code number 918. I have never seen, owned, or heard of them before, so I have no idea of their value. You should do what we all do when confronted by an item we don't know much about.....do an Ebay search and see if any are listed or have sold. That would be the best assessment of value.
Wow... Doug, your craftsmanship is literally impeccable... your amps and trucks and all the other things you show that you built are awesome... I'm proud to know you. :-)
Job well done Uncle Doug!! I am learning so much from studying your designs and workmanship on these one off amp builds.. I’m seriously thinking about ordering my first amp build.. thank goodness I’m good with tinkering..retired fabricator/welder/ Sheetmetal worker.. simply amazing work, yours(probably not the right word describing your articulation in amp repair/building)..it is truly a nice way for passing away my evening free time...way better Hogan’s Hero’s reruns!! 👌 Here’s to You and Family having an awesome 2019!!
I just soldered my very first joint (practice bits) and I feel like Jesus just kissed me full on the mouth. Never take anything anything anything for granted. First solder. I rock.
"Crocodile skin -I guess" Hahaha, you always find space for humor Uncle. Loved the sound of this little beast! Super defined and present. Thanks for sharing!
That froggy is pondering on HOW THE F will I fix my Princeton Reverb right... The people over here in Puerto Rico don't seem to get it right, ever! Sheez... T_T
+Uncle Doug I know I will, and your videos will be instrumental. You have given us, your viewers, the beautiful gift of wisdom by sharing your experience. And I know how to discharge the filter capacitor so I'll be good to go.
Nice call on using the 15 inch speaker. The amp sounds terrific. Usually I'm satisfied with your playing (or is it Rusty?) on the demonstrations, but this amp sounds so good that I couldn't help wishing that a test pilot more along the lines of Billy Gibbons had been there to plug in. He's the kind of guy who is sensitive to what you are doing with an amp like this and would know how to nudge it in all the right revealing ways. Anyway, very nice amp.
+ironpirites Thanks, IP. My choice of 15" speaker was partially due to the fact that some forms of the original Model 26 came that way....and partially due to the fact that I had a really nice, vintage 15" speaker that was begging to be used :) Anytime Billy is available for a demo, Rusty and I will welcome him with open paws. He occasionally visits a recording studio nearby.....maybe we can bribe him with promises of beer and Mexican food :)
Uncle Doug I think he has quite a collection of vintage amps, large and small, so he would be right in tune with the sort of thing that you like. It would be great to hear him checking out the playing parameters of some of your stuff. A fun thing to think about. Ya never know . . .
Doug, You have outdone yourself on this build... It really looks and sounds special! Your p2p as always, is a stellar show of craftsmanship as well. Hope you aren't planning to fire up the buffing wheel as a "Stunt Of The Day" with the muslin hanging in the wheel. Old folks like us should have stopped doing things like that for excitement by now... At least too often 🙂 Thanks again for sharing another one from The Uncle Doug Files!
Doug, I've been wondering about filter chokes when and where to use them. It might make an interesting video. How to chose the values would also be helpful. Thanks again. Very interesting video. I picked up a deluxe clone today whilst buying some speakers! After doing some repairs to it it sounds gorgeous.
Thanks so much, Jimi. Of all the amps I have built, this one is still special to me. It was a long shot, but it turned out much better than I had hoped.
Great video and cool amp. I actually own a real model 26, I don't turn it on/plug it up obviously because it's never been serviced...but really I don't know how to proceed with it, to service it and keep it original/retain it's value and mojo. I think you'd dig it!
That is SO Beautiful and so Professional Made, you could sell these on Ebay and make a Mint ! ..as I would Bid and love to Own, But like your self after so much time and effort I'd keep her .. after all you created Her !! I use to take Phono tube amps and make my own cab's ..and moddified an old Fender bassman 100 in my video's for Guitar and used a Peavey cab 2-12 fit perfect, had to cut the angle and loved the wood work with dove tail joints Thanks for Posting these Video's as they are inspiring and thrilling :)
You can improve on the artificial center tap on the heater winding by installing 'humdinger', a 500 ohm pot wired across the winding with its wiper to ground. The pot can then be adjusted for minimum hum.
Chris, it's a shame you're eliminating the 6N7's. They're an uncommon, but great-sounding tube. When I first completed the amp, it's sound was far from impressive and the old 6N7 I used was microphonic, so I hunted down an NOS 6N7......the difference was astounding. Also, multiple 8" or 10" speakers is a great idea. Check out my videos on the Magnatone Melodier, Gretsch 6161, and National Aztec. Multiple small speakers provide a unique, dynamic sound.....like a chorus instead of a soloist.
now that amp does sound good ! I'm startin to think the 6SC(N)7 's are better than 12AX7 's " hawaiian love songs " I was trying to forget all about that
How fantastic is THAT ? Must sound incredible in person. UD, I love that 15" spkr..I have one very similar in my shop...it's from a Hammond organ, and it looks identical, but probably isn't. *heh*.... NICE WORK.
Carl Rudd Thanks, Carl. It does indeed sound wonderful, especially in person. I'm a fan of 15" speakers. Some people prefer smaller speakers due to more favorable cone dynamics (less mass, more rapid response), but in my book, especially for rock music, no single speaker can match a big, powerful 15". You're right, it is a "retired" completely original organ speaker. I get lots of (very high quality) components from old organ amps and sound cabinets.
My very first amp was a narrow panel Tweed Pro with a 15. That was a powerful amp. Wish I still had it. That was in 1964 - traded it in on a 'brand new' Gibson Mercury II gutless wonder amp.....one of the worst decisions I ever made.
Immediately exchanged the Mercury II for a Gibson GSS-100, which had plenty of power..... transistor power. Remember, in those days it was all about trading in for whatever the store had on the floor.
Giod choice of music. The first one is run a way, by Del Shannon and the second one is Pretty Woman, by Roy Oberson. OH MY GOSH, I just gave away my age😀.
I also possess dozens of illustrations - most in a journal, drawings and photos. As a book enthusiast - "readers" I, like Mister Lennon, will illustrate whatever is relevant. The pics alone are worth the price of admission. Portraits of punks'n'folks, alive and dead. Drunken and twisted fantasies. The only photocopy of the Beatles portrait that I drew in 1967 is in that journal. Imagine using a 6B pencil for 230 hours drawing your heroes. The Xerox is disintegrating so should be scanned. My neighbor down the hall just bought a scanner and he is turning his apartment into a petri dish so perhaps he has lost his mind. Many folk are adopting the petri-dish approach to their environment. Then Dhani Harrison plays a George song in YT - the Inner Light, which I've been singing and playing for 54 years. Why do folk turn their homes into giant petri dishes? Is it a Fox news thing?
Wow! I really really like that! I have zero skills in electronics, although i can make a nice cabinet. Thing is, i need a good little bass guitar amp like that. I have no idea how to make an amp like that suitable for lower volume bass. But the look of it is just beautiful, and the controls are all i want, a volume, tone, off/on. Guess i need to do more research and learn how to make a small bass amp like that. Man that beastie sounds cool though!
Thanks so much, Nusior. This is probably my favorite of all the amps I have built. Once I found a really good, NOS 6N7 for it (no easy task) it just "took off" with tone and volume that equal most (if not all) of my vintage amps. Rusty and I really appreciate your time and interest :) ^. .^
ah.very interesting..nice build .One of my radio/phono consoles (RCA VRA 121 ) uses a 6SC7 as phase inverter., and I have an old 6L6 push/pull amp that I am rebuilding that actually originally used 2 6N7's ,but I am rebuilding it from a schematic that uses 6SJ7's and 6J5 asphase inverter. I think it would be interesting to see how different an amp like this might sound using two- four 8 inch or 10 inch speakers as opposed to one 12 or 15 inch speaker
Very cool! I may be turned nah an 50’s Olsen hifi into one of these for someone since it has mostly the same tubes. A woodworking friend is going to build a replica Woody Art Deco cab for it ,too. I was wondering if the tone pot might be better off (and safer) somewhere else,as well.
I love the baffle in the style of your 1947 National. Great touch! The speaker basket seems to resemble a Magnavox, but I have seen that speaker code on a driver from a "Califone" record cabinet... that speaker's basket looks like a Utah... This may be more confusing than helpful, but I hope it helps! I also wanted to mention the control scheme... I think someone else made a comment regarding the 5E3... I recently repaired a gentleman's 1954 Fender Pro amplifier. The controls were exactly the same as this and the 5E3, where the volume are interactive... a very peculiar circuit indeed. Regarding the Pro Amp, it was a real treat for me being the oldest piece of guitar gear I've ever played through, let alone had the pleasure to work on. The original Jensen P15N was even there and in spectacular shape to boot! The worst offense was the blonde(ish) tolex somebody used to cover up the (probably tattered) tweed - there were traces of some unidentified pink goop (contact cement?) between the two layers. At least the original grill cloth was still there (under a layer of modern poly-oxblood) - a little bit of stretching and it was almost like new! I wish you could've seen it.
Greetings, Britt, and thanks for the kind words re the speaker baffle. The speaker code is 583525, and according to my list, 583 indicates Magnavox....probably the 25th week of 1955 (not 65, I would guess, based on the style of Alnico magnet). What a shame that someone covered over the original tweed on the early Pro amp, especially after slathering it with pink contact cement :( I always cringe when I see these counterproductive "repairs".
Do you have the parts list for this amp. I would like to find some of these vintage parts and try building one. I find your videos very interesting and I thank you for that. It is great, that you share your knowledge.I have some basic electronic education and your videos have made me interested in electronics again. Thanks
Greetings, 330, and thanks for the kind words. I have no plans or parts list, other than a schematic I downloaded on the Internet. When I build, I generally do so without plans, simply making things up as I go. I can tell you that I used the power transformer, output transformer, and filter choke (I installed one, even though the original Model 26 didn't use a FC) from a Deluxe Reverb amp. You could also use the PT and OPT from the 5E3 Deluxe if you wished. I also moved the tone control from between the output tubes and OPT to the volume control circuit (just after the 6SC7). I encourage you to build one of these jewels for yourself.....the tone is exceptional !! Good luck.
Very cool UD! Sounds very similar to mine but I’m I’m trying to eliminate some 60hz hum. May just be coming from the power transformer but I’m hoping I can fix it by finagling the heater wires. I’m running out of options pretty quickly! Hopefully I’ll figure it out. It’s not HORRIBLE but it just bugs me.
Another great video Doug! Some beautiful work here (ya gotta like a guy who designs his own chassis and cabinet)! Walking through the circuit, I'm reminded of some similar circuits in other old amp designs that seem to use the grid leak resistor but omit the grid stopper resistor in the single "Mic" input but do the opposite in the "Instrument" input (i.e. have grid stopper but no grid leak resistor) - like we have here in the 26. If you have time for a question - what's up with that? In any case, thanks for these videos - I've learned more from them and you than a lot of years of reading books!
Thanks, Richard. I believe the reason is that instrument, i.e. guitar, input signals are much stronger than microphone signals, thus the grid stopper may be needed for them, but not for the microphone input. In my revised schematic for the Modified Model 26 Deluxe (see link in video description), both inputs have identical grid stoppers, but the grid leak resistors are quite different, to provide different input impedance and gain.
Thanks so much, Ron. Yes, I occasionally sell my vintage and home-built amps. If you are interested in any specific ones, please send me a personal message and I will provide the details, like shipping and price.
Gavin, I gather that you don't play the guitar and thus have no use for the amp......so, other than sending it to me :), you might consider listing it on Craigslist, if you are near a big city, or on Ebay. They are quite rare, but appeal to a limited group of collectors/musicians (like me and a lot of subscribers to this channel) who tend to favor older vintage amps. Working or not, it would be of great interest to one of us.
It was generally for microphone (singing) and instrument (lap-steel guitar). The impedance had to be different to match each input.....but people soon discovered that they could plug a guitar into the microphone (louder) input and make more noise.
I wasn't aware they had such adapters, Petar. If they are available and from a reputable source, I see no reason why you couldn't use it. Is it prohibitively expensive to simply order a couple 6SC7's from the US ?
Hi Doug....I continue to be impressed by this build. Great schematic mods. Does the dotted lines in the circuit represent a shielded wire? Also, I see a capacitor connected to the fuse in the video and the original schematic, however, it isn't present in the updated schematic. Moreover, I would think that this is a death capacitor but you have a three prong cable. What is that capacitor used for? Thanks! Bart
+redfishbum Thanks, Bart. This ended up being a really nice amp. If the dotted lines are on both sides of a solid line, then they indicate a shielded cable. The "death cap" helps to eliminate any electrical noise that comes in with the 120VAC in the primary circuit. They work with both two (if the plug is oriented correctly) and three-wire power cables.
Uncle Doug. Love your videos, I'm learning a lot from them. Can you explain why the grid of the 2nd preamp tube connects to those resistors (10K, 250K)? Is this just another amplification stage after the first half of this tube or something else? What do you call this stage?
+Dan Cullinane Thanks, Dan. Actually, the 6N7 is a Paraphase Phase Inverter, which provides an in-phase signal to one of the output tubes and an out-of-phase signal to the other one, so they can provide the push-pull signals for the output transformer. I explain this better in my video on Phase Inverters.
I borrowed a trick from the Bassman and put them all on the rear of the chassis, near the power transformer, facing the speaker. If you look at photos of the amp during construction (posted on my Uncle Doug's Vintage Amps Facebook page) you will see them.
Hey Uncle Doug....I've been kicking around another build in the future (crazy me but I absolutely love the Supro Clone that I cloned after yours!).....I've been looking at alnico speakers on eBay. Thoughts on a single 15" as you have here or twin 10" or 12"? Overkill for this design? Thanks!
You're welcome, Bart. I'm torn between both of your options. Nothing conveys bass and power any better than a big 15" speaker......but multiple smaller speakers can be really impressive too. I recall the brownface Concert amp I restored a couple years ago, putting an orphaned chassis back into an original 4 x 10" cabinet with new, good quality speakers. The moment I struck a chord through it, I felt shivers up the spine. It was spectacularly nice. I think if you are limited to two 10" or 12" speakers, I would do something unusual and use mismatched speakers, i.e. one Alnico and one Ceramic. You would have the best of both worlds.....and a truly rich, full sound.
Looks good and sound nice! In the late 70’s I’ve build my first tube amp from an old radio my father gave me. I used a transistor amp from an old recordplayer put it in front of the tube amp and it sounded amazing, like a Marshall, I remember my father being proud of me. I was about 14 years old. I’m still building my own amps and effect pedals and I’m still learning a lot by watching your video’s! Very inspiring too! Thanks👍
You're welcome, Ricky. Keep up the good work :)
Uncle Doug...I am humbled to be able to experience the unbelievable patience you have to slow everything down, edit tape, explain, draw diagrams, entertain us with pet antics...I have modified, built, serviced, styled quite a few amps/pedals with high regard in my area...even fixed air conditioners, heaters, lamps, aviation headsets, stereos, wired entire garages with electricity you name it...all because you took the time to make these videos for us! Thank you for that, thank you so much for that. I sincerely hope that you continue to have the love in your heart to pass on the secrets of your trade to those of us who will keep the skill alive into the future....Each of these videos are going to be the documentation of the characteristics of each of these vintage amps as a library to the rest of us someday....
Having said that...as a musician...is there any way you can incorporate a higher decibel-level microphone in order to dial up the input gain to higher levels like around 5-7 (not cranked, I absolutely hate any person who uses the word "CRANKED" in any amp video title or description) so that we can actually hear more of the tonal effects of the entire system under a higher drive? I feel that every end-result testing at the conclusion of your videos with volumes at two tend to sound very similar with the amps you build/service and the system effect/impact on distortion/tone is not entirely communicated.
I am a humble student. I hope you will consider my suggestion. Thank you for your time.
Marlon
Thanks so much for your very kind and generous comments, Marlon. Rusty and I are quite pleased that our videos have enabled you to accomplish so much in the area of electronics repair. I fully understand your recommendations on how to improve the audio testing of amps and agree that my methods are definitely sub-optimal. My video camera does not allow for the use of a separate microphone, so each audio test is hampered by the limitations of my equipment (i.e. grain-of-rice-sized microphones). One of these days, I fully intend to invest in a better, more flexible, video camera that will allow for higher fidelity and volume recording. Meanwhile, thanks so much for watching, commenting, and offering good suggestions.
Outstanding job, I love the rear panels and way the sides/top/bottom wrap around part of the front to meet the groovy red grill. The red with black gator skin is perfect. Really nice layout and install of the electronics. Looks and sounds great.
True craftsmanship.
+bru th Thanks so much, Bru. Rusty and I really appreciate your very kind appraisal. Glad you liked the amp. Thanks for watching and commenting :)
Great looking amp, and a good history lesson in Fender amps. Sounds great. Thanks for posting!
You're welcome, Norm. I'm glad you liked the video :)
That amp sounds like a million bucks! Awesome build Doug.
Thanks so much, FM.
I absolutely love you videos. They are very helpfull.
I have a suggestion though. You have no reason to apologize for your guitar playing. My wife put it well to me one day.
She told me that people who enjoy watching me play and sing would rather not hear my apologies.
Your playing serves the purpose. It is very good compared to the majority of people standards. Apologies start sounding like excuses. To those that don't play as good as you it can be disheartening to them. Some wish they could play as good as you.
You are a wise talented man and I hope that you take this as a compliment and advice from someone who has learned from his wife of 30 years. People are very apprecitative of me not whining anymore. Keep up the good work. Thank you for all you do.
Ron Mason Excellent advice, Ron. My thanks and best wishes to you and your wife.
Uncle Doug It worked well for me. Listening to my wife that is. I do appreciate all that you are doing to help people on UA-cam.
Thanks Ron.
You're welcome. Our best to you all.
Real music played from the soul is always good! John Lee wasn’t a technically great player but, he was one of the best players! It’s not how good you are but how good you are. Rock on! I like your playing!
I agree. Virtually all the speakers I have removed from organ tone cabinets have been Magnavox, code 232. I should have mentioned this in the video. Thanks for your input.
The sound was very similar to the original. Congratulations!
Thanks, GA :)
I love your take on the Woody! You're an artist... and I love that you share your thought process before you start to build. Adding "grid stoppers" and the Choke were also smart ideas. The Supro "24" (6424) uses the same Quasi "Long Tailed Pair" Phase Inverter. This is one of my favorite inverters because, if you voice it properly with the right coupling caps, it creates some gorgeous harmonics when pushed. The reason some of those old design caps sound so rich and unique, is because their tolerances are sloppy. When we look at today's tight tolerance caps, and apply the RC Time Constant Math and Frequency Calculations, we see a very precise Frequency Response and Tone behavior. When we insert a leaky loose tolerance cap... the frequency and tone response isn't quite so sharp and precise. You might say that they're softer. I've actually rolled my own tone caps before. You can also use some fancy frequency test gear and see the difference when you sweep them with an audio frequency. I think Leo opted for controlling tone for his guitars by selectively using gain stage coupling caps, instead of a complex control that steals the guitar's chime, and also relying on the guitar's volume and tone controls. Moving the tone control was a brilliant idea. The stock Woody is more of a Vox High-Cut approach, had it been a little closer to the phase inverter. Back then they weren't over-driving the front end with pedals. I've recently started a Supro 24 build that is using (4) EL34's for the finals. (EL84's would have also given the Woody a sweet grit.) I'm wrapping up the bias board and then it's time to fire her up. The Woody and the 24 are great brothers and sisters, but you need a little more oomph if you're going to gig a larger venue. The 34's should enhance the Quasi Inverter harmonics... I'm going for something Janis Joplin... a little raw and nasty... Thanks again for another history lesson!
The 15" speaker was also very smart... when you add, say a decent 12" to a Champ, the voice opens up like the heavens. Those small speakers choke an amp. I also love the semi-open backed cab that you built! A closed cab should be left for a bass rig. lol
Say... there's a great little hack that you can add to an amps power supply to silence the hum in place of a choke; although I prefer the choke like you used. (On a vintage restore, the added holes for the choke are frowned upon, whereas the added cap and resistor are harmless.) Add a 20uf to 80uf electrolytic cap right after the rectifier, and then a 100 ohm to 250 ohm 5 watt resistor, to strip off some 60 cycle noise before the B+ goes to the output transformer. This works great on a single-ended amp like the Champ, and the lower power push-pull rigs. So it's... power output tranny to rectifier to a 20uf to 80uf cap to ground (with a 220k safety bleed resistor in parallel with the cap to drain the cap when the power is off) to a 100 ohm to 250 ohm 5 watt resistor to the output transformer B+ (that also has at least a 16uf cap to ground) and then to the rest of your power supply resistors and filter caps. One other note... with the added cap, you want to use the smallest cap that will do the trick for you. Larger caps do put a strain on the power supply transformer. On Champs, I use a 20uf 500 volt cap with a 250 ohm resistor and they run whisper quiet. Again... the choke is a much better option if you can get away with it and an added filter cap will affect the "sag." I've also added a filter cap right after the rectifier and then a choke, and then the OT B+ with great results, too. Oh... and if you want to add a "standby switch," place it right after the 250 ohm 5 watt resistor and before the output transformer B+. You can also add a 100k 1/2 watt resistor across the standby switch to bleed a little voltage across the switch to keep the filter caps slightly charged in order to lower the current inrush when the switch is turned on and to prevent arcing.
Thanks for your nice comments and a great deal of informative, helpful information, Mark. Viewers like you definitely make the YT learning experience a two-way street. I am in complete agreement that much of the "vintage tone" associated with old amps.....and missing from the new ones.....is due to old, out-of-spec resistors and capacitors providing warm, imperfect, analog, harmonic-rich output that simply cannot be matched with precise metal-film resistors and high-dollar capacitors. To me old vs new is like a Rembrandt painting compared to an Etch-a-Sketch.
Right on... Teamwork... And community... And yes... Analogue can never be duplicated digitally. Glass will always be in style.
Amen, brother :)
WOW! EIA code 513 was originally allocated to The Houston Transformer Company of Houston, Texas. Yes, of course, they did electrodynamic speaker and PM speaker voice coil winding, and even cast their own speaker motor parts too. I do not know if they stamped frames out or not, but they did smash stamp the motors' cast bosses onto the stamped metal frames. What a rare bird.
Thanks for the informative input, Seth.
Spectacular build - see your virtual center tap once again.
Thanks, John. Of all my home-built amps, this one turned out to be the best with regard to tone and power, and is one of my favorites. Yes, the old "virtual center tap" trick was once more employed to reduce hum (which is "virtually" non-existent) :)
That is one nice sounding amp. I bet it sounds great cranked.
Thanks, HA. It is indeed one of the best sounding amps I have worked on...or made.
A masterpiece, sir. As ever. 15" speakers are so unstressed. Good choice 👍
Thanks, Bill :)
One of the most balanced tones I've heard from and amp.
Thanks, PW. I'm glad others like the tone of this amp.....it's one of my all-time favorites :)
Uncle Doug you are a great teacher. I wish you were my uncle so I could hang out in your shop and work on this stuff with you!
+James Leinbach Thanks so much, James. Perhaps I can adopt you as my nephew :)
Thanks for the nice note, BC, and thanks for subscribing. There are many more similar videos on the way...........
i could watch your videos over anything thats on TV. great job Uncle Doug!
High praise indeed, Trevor. Thanks :)
Great point to point vintage amp gorgeous one
Thanks, Hugo :)
wow, I could imagine the sound in person. wonderful, no need to apologize to Roy I am sure he is proud. he is my favorite singer /artist, I sing very much like him and many other people. just for fun. your work is out of this world man!!!!
+jeff b Thanks so much, Jeff......glad you liked it :)
Tis a thing of great beauty uncle doug ! showcasing your usual
impeccable sense of taste in all things electronic and otherwise,
for that matter😎 cool is ,,as cool does !
Thanks so much, William. It is one of my all time favorite homebuilt circuits.
Very nice build and deathly quiet... Great sound too!!!
Thanks, Otter. Of all my scratch-builds, this is my favorite. As you say, the tone and silent operation (I added a filter choke plus some other updates) are exceptional.....and who would have expected it from such an early circuit design?
Leo Fender would love this amp. It's amazing. Beautiful tone!
High praise indeed, James. Thanks so much.
"...I'm a-walkin' in the rain,
Tears are fallin' and I feel the pain,
Wishin' you were here by me,
To end this miz-zar-ee,
An' I wonder"...,etc. And that amp is really Really beautiful... I'm surprised no one's approached you to market it... yeah, just stunning. Thanx Uncle Doug and...
cheers
Thanks, Jonny. It's still one of my all-time favorite amps....and tunes :)
Hi Doug The 1946 Woodie Fender Pro used a 15” Field Coil Speaker. I still own the 1996 repro of that model from the fender custom shop for its 50th anniversary of Leo Fenders First amplifier. I haven’t been able to ops check it, I had some problems with it from day one blowing tubes. We corresponded about it but I haven’t been able to budget shipping it to you to restore it.
I remember it well, Joseph. Let me know if you do find a way to afford the shipping and repair. It would make a very interesting video.
Man what a nice little amp. Immaculate. Sounds great! Nice job!
Thanks, Ron.
wow! a tone control after the power tubes, now that is sonthing you don't see every day! Amazing amp, the circuit is ancient but it sounds great!
Thanks, Josef. The original circuit had the tone control after the 6V6's, but I moved it to a more conventional location after the pre-amp and before the phase inverter. I'm glad you like the tone.....it's one of my all-time favorite amps.
Sounds great and looks awsome. I love point to point wireing, easy to trouble-shoot and repair.
Thanks. Agreed :)
Looks and sounds great.
Kudos Doug
What a nice looking and nice sounding amp! I liked that the circuit was point to point. No turret board necessary! Great work!
***** Thanks, Alva. I think point-to-point is the "purest form" of circuitry. The other methods are simply ways to facilitate mass production and minimize expensive, skilled hand labor.
Uncle Doug I agree. My preference is for turretbboards in my own amps, because I like the ease it provides in modifications, and I suspect components are the most secure with turret boards, but the beauty of point-to-point is hard to beat.
Thanks so much, BT.
JZ, over the years I've accumulated lots of NOS brown, carbon resistors, but only use them when repairing a vintage circuit, so the replacement resistors match the old ones. In my scratch builds, I use metal-film resistors and occasionally, new carbon resistors of 1 watt (or higher) rating. I've heard that metal film resistors have a negative effect on "vintage" tone, but have never seen or heard any direct evidence of this being true. IMHO, their precision, longevity, and tone are superb.
Hi Uncle Doug , Nice build , your model 26 sounds great . I own 2 Model 26 Deluxes from May 1946 and they don't sound as nice as that one you've made . There's a couple of differences between the schematic you used and a real one , Mainly in the tone stack . Leo Fender used a very primitive tone stack for the "Woodie" Deluxe . He used a 0.05uf 600v capacitor that was fed through a 500kB pot between the 2 anodes of the 6V6 output tubes . the 3rd lug of the pot wasn't used . He also used a 300ohm resistor to bias the output tubes with a 10uf cap. and he had no resistor between the input jack on the Mic channel and the grid, it was just straight into the grid. The resistor from the Mic input jack to ground was 2 Meg and there was no resistor to ground on the Hi / low input of the instrument channel. (they had 3 inputs 1 x Mic , 2 x Inst). But the instrument channels two inputs were wired the same way later fenders were so you had a 6db difference between the two inputs ... I personally prefer plugging into the Mic inputs on mine , it sounds so much crisper and dynamic than the instrument channel .... I hope this information helps . I've sent Tommy the diagrams explaining all this , regards Mark
We're aware of the differences between the original schematic and my new, improved circuit, FAF. The changes were made to provide superior tone, component safety, and longevity......as you noticed. When cloning very early, primitive circuits, it's generally best to update them a bit with some more modern design technology. Thanks for your input.
I agree @@UncleDoug that tone circuit on the original is very scary ... if the coupling cap opens it's Anode onto Anode ... BOOM
what a most beautiful build. Blessings uncle Doug!
Thank you, Barry. Likewise on the blessings :)
Thank you for sharing the updated schematics! I'll try to build this amp (or maybe a bit modified) into an old-ish combo. Alas, the 6N7 is rare in the EU, so maybe a substitute will be needed. 6SL7 might be a bit stout, the 6SN7 a bit weak, but the latter might drive the output tubes enough to get close to the sound of the old Model 26 :)
You're welcome, Y. Good luck with your project.
Those loudspeakers were commonly used in Magnavox consoles of the day. Particularly the Magnavox Imperial/Concert Grand, I believe they are Jensen manufactured specifically for that purpose.
Thanks for your input, Alex :)
No problem. The hole in the center of the magnet was actually for a black plastic cap that would go over it in the sets. Here's one in it's natural habitat www.radiomuseum.org/images/radio/magnavox_co_fort/imperial_classic_1_st233_ch_6401_00_1523745.jpg. I work on a lot of these bi amp chassis so I always have a spare horn and woofer. Hard to not recognize them now!
It does have a Magnavox EIA code. If Jensen had manufactured it, I would expect to see the Jensen code (220).
232 is Magnavox, who made a lot of speakers and provided them for early radios and amps. That one is early, similar to a 40's Jensen magnet. Of course I am sure you know Peter Jensen designed speakers for Magnavox before he went out on his own. Anyway cheers Sir.
Thanks for your helpful input, SHW.
Even with the shortcomings of the camera mic, it still sounds very warm and round. The key (IMHO) is that it sounds warm/round AND clear with good note separation. For me, that's the perfect guitar tone. Thanks for sharing. Love the 15" speaker.
+quicklynamed You're welcome, QN, and I agree completely. The tone is exactly as you describe and I give much of the credit to the vintage 15" speaker. Thanks for watching :)
I agree, this is an incredibly good sounding amp. Full of, well, LIFE! A bit more of the overdriven sound would have been nice.
Oaktron speakers are code number 918. I have never seen, owned, or heard of them before, so I have no idea of their value. You should do what we all do when confronted by an item we don't know much about.....do an Ebay search and see if any are listed or have sold. That would be the best assessment of value.
Wow... Doug, your craftsmanship is literally impeccable... your amps and trucks and all the other things you show that you built are awesome... I'm proud to know you. :-)
Thanks so much, Terry. This was one of my all-time favorite amp builds.
Right on... you're welcome. :-)
A great sounding amp Doug very nice looking too,oooo!
Thanks, David. It's one of my all-time favorites :)
Job well done Uncle Doug!! I am learning so much from studying your designs and workmanship on these one off amp builds.. I’m seriously thinking about ordering my first amp build.. thank goodness I’m good with tinkering..retired fabricator/welder/ Sheetmetal worker.. simply amazing work, yours(probably not the right word describing your articulation in amp repair/building)..it is truly a nice way for passing away my evening free time...way better Hogan’s Hero’s reruns!! 👌 Here’s to You and Family having an awesome 2019!!
Thanks so much, Luth. Best wishes for great success with your new hobby and in the New Year.
The amp sounds great too!
Thanks, William. It's one of my favorites.
your chassis designs are gorgeous!
Thanks so much, 442 :)
Very nicely build, very clear sound.
+RODALCO2007 Thanks, Rod. Glad you liked it :)
I just soldered my very first joint (practice bits) and I feel like Jesus just kissed me full on the mouth. Never take anything anything anything for granted. First solder. I rock.
Congratulations, B, and best wishes for many happy solderings in the future.
WOOW!! Beautiful clean sound!!
+MrFosamax Thanks, Mr. F. Of all the amps I've built, I would place it in the top 2 or 3 with respect to tone. You have a good ear :)
That's one handsome looking and great sounding little beast. I like it.
Sounds great!
Thanks, Mario. I was real pleased with how it turned out.
Super nice!!! Love these builds , they all sound awesome!!!
+Jethro Mann Thanks so much, Jethro. Rusty and I really appreciate the kind comments.
NIce to save the history of the unit
+James Hurley It always helps to do research on any amp that is restored or even scratch-built.
Happy to be 1000.
Thanks for watching, Joe. In honor of being the 1000th viewer for this video, you win a free subscription to my channel !! Happy New Year ;))
"Crocodile skin -I guess"
Hahaha, you always find space for humor Uncle. Loved the sound of this little beast! Super defined and present. Thanks for sharing!
You're welcome, Fuga. From the looks of your icon photo, you're no stranger to amphibians and reptiles :)
That froggy is pondering on HOW THE F will I fix my Princeton Reverb right... The people over here in Puerto Rico don't seem to get it right, ever! Sheez... T_T
I understand, Fuga. I hope froggy can figure it out :)
+Uncle Doug I know I will, and your videos will be instrumental. You have given us, your viewers, the beautiful gift of wisdom by sharing your experience. And I know how to discharge the filter capacitor so I'll be good to go.
Sounds good, Fuga. Thanks so much for your very nice comments, and best of luck with your repairs.
Really nice!
Thanks, VC. It was one of my best ever.
Nice call on using the 15 inch speaker. The amp sounds terrific. Usually I'm satisfied with your playing (or is it Rusty?) on the demonstrations, but this amp sounds so good that I couldn't help wishing that a test pilot more along the lines of Billy Gibbons had been there to plug in. He's the kind of guy who is sensitive to what you are doing with an amp like this and would know how to nudge it in all the right revealing ways. Anyway, very nice amp.
+ironpirites Thanks, IP. My choice of 15" speaker was partially due to the fact that some forms of the original Model 26 came that way....and partially due to the fact that I had a really nice, vintage 15" speaker that was begging to be used :) Anytime Billy is available for a demo, Rusty and I will welcome him with open paws. He occasionally visits a recording studio nearby.....maybe we can bribe him with promises of beer and Mexican food :)
Uncle Doug I think he has quite a collection of vintage amps, large and small, so he would be right in tune with the sort of thing that you like. It would be great to hear him checking out the playing parameters of some of your stuff. A fun thing to think about. Ya never know . . .
Stranger things have happened, IP.....and it never hurts to dream :)
Great build! Very clean and inspiring........as usual.
+redfishbum Thanks, Bart. It's one of my all-time favorite amps......homebuilt or manufactured.
love you videos very helpful you do a great job of explaining things
Thanks, LS. Glad to hear it :)
Doug,
You have outdone yourself on this build...
It really looks and sounds special!
Your p2p as always, is a stellar show of craftsmanship as well.
Hope you aren't planning to fire up the buffing wheel as a "Stunt Of The Day" with the muslin hanging in the wheel.
Old folks like us should have stopped doing things like that for excitement by now... At least too often 🙂
Thanks again for sharing another one from The Uncle Doug Files!
You're welcome, John. Thanks so much for your very nice comments :)
Nice sounding amp. Thanks.
+Gunnar Örn Knutsson Thanks, Gunnar. In person, it sounds even better. Of all my hand-built amps so far, I think it sounds the best.
Doug, I've been wondering about filter chokes when and where to use them. It might make an interesting video. How to chose the values would also be helpful. Thanks again. Very interesting video. I picked up a deluxe clone today whilst buying some speakers! After doing some repairs to it it sounds gorgeous.
Very Nice!
Thanks, Tom. It's one of my favorite amps.
Great Video ,GREAT sound man !!
Thanks so much, Jimi. Of all the amps I have built, this one is still special to me. It was a long shot, but it turned out much better than I had hoped.
Great video and cool amp. I actually own a real model 26, I don't turn it on/plug it up obviously because it's never been serviced...but really I don't know how to proceed with it, to service it and keep it original/retain it's value and mojo. I think you'd dig it!
Check my video list for videos dedicated to the Fender "Woody" amps, P, including one that will be posted quite soon.
Hey :-)
Your videos are just great... cool tipps and stuff... just built my own a really nice class A all tube bassamp :-)
Rock On and On an On
MB
Thanks, MB. We're glad the videos are helpful.
Beautiful work !!!
Thanks, Kal. It turned out to be one of my favorite amps......great tone.
Thats just beautiful work ... Thats nice hand wired stuff Nice and tidy ))) super amp ))) sounds great
Thanks, AT. We really appreciate your nice comments :)
Yea , Well deserved ... ))) ... I am infatuated with that Bassman ... That is really something as well ... )))
That is SO Beautiful and so Professional Made, you could sell these on Ebay and make a Mint ! ..as I would Bid and love to Own, But like your self after so much time and effort I'd keep her .. after all you created Her !!
I use to take Phono tube amps and make my own cab's ..and moddified an old Fender bassman 100 in my video's for Guitar and used a Peavey cab 2-12 fit perfect, had to cut the angle and loved the wood work with dove tail joints
Thanks for Posting these Video's as they are inspiring and thrilling :)
Thanks so much for the kind words, B2. It sounds like you have some woodworking experience. I really appreciate your input :)
Great job Uncle Doug,better than the original,hands down.
High praise indeed, John. Thanks so much :)
You're welcome! Looking forward to seeing more :)
You can improve on the artificial center tap on the heater winding by installing 'humdinger', a 500 ohm pot wired across the winding with its wiper to ground. The pot can then be adjusted for minimum hum.
Indeed, Silas. Some amps come already wired with this pot. It is an excellent idea.
Thanks a lot, great video !
Thank you, DXT. Glad you liked it :)
Chris, it's a shame you're eliminating the 6N7's. They're an uncommon, but great-sounding tube. When I first completed the amp, it's sound was far from impressive and the old 6N7 I used was microphonic, so I hunted down an NOS 6N7......the difference was astounding. Also, multiple 8" or 10" speakers is a great idea. Check out my videos on the Magnatone Melodier, Gretsch 6161, and National Aztec. Multiple small speakers provide a unique, dynamic sound.....like a chorus instead of a soloist.
Very shimmery sounding (at least what I can hear through the camera mic.) Would make a great recording amplifier! Looks like a 2000 dollar amp!
Thanks so much, Bryan. To be honest, we like it so much it would probably take that amount of money to pry it from Rusty's paws :)
now that amp does sound good !
I'm startin to think the 6SC(N)7 's are better than 12AX7 's
" hawaiian love songs "
I was trying to forget all about that
Rusty and I dearly love the sound of early octal pre-amp tubes, like the 6SL7, etc. To us they sound even "tubier" than the venerable 12AX7.
beautiful job and I've have to concur with your choice of 15 , to me it gives a better rounder sound
How fantastic is THAT ? Must sound incredible in person. UD, I love that 15" spkr..I have one very similar in my shop...it's from a Hammond organ, and it looks identical, but probably isn't. *heh*.... NICE WORK.
Carl Rudd Thanks, Carl. It does indeed sound wonderful, especially in person. I'm a fan of 15" speakers. Some people prefer smaller speakers due to more favorable cone dynamics (less mass, more rapid response), but in my book, especially for rock music, no single speaker can match a big, powerful 15". You're right, it is a "retired" completely original organ speaker. I get lots of (very high quality) components from old organ amps and sound cabinets.
My very first amp was a narrow panel Tweed Pro with a 15. That was a powerful amp. Wish I still had it. That was in 1964 - traded it in on a 'brand new' Gibson Mercury II gutless wonder amp.....one of the worst decisions I ever made.
Wow, that really was a step down, Carl. I guess we've all made similar errors in judgement when young, that we (thankfully) lived to regret.
Immediately exchanged the Mercury II for a Gibson GSS-100, which had plenty of power..... transistor power. Remember, in those days it was all about trading in for whatever the store had on the floor.
Ugh, things went from bad to worse....but such are the mistakes of our youth :)
Giod choice of music. The first one is run a way, by Del Shannon and the second one is Pretty Woman, by Roy Oberson. OH MY GOSH, I just gave away my age😀.
Thanks, Cliff. You can always claim that you heard the tunes on your father's record player while still a tot :)
back of amp door on, then door off, was like dance of the seven veils starting up
Yep, I try to keep the audience on the edge of their chairs :)
I also possess dozens of illustrations - most in a journal, drawings and photos. As a book enthusiast - "readers" I, like Mister Lennon, will illustrate whatever is relevant. The pics alone are worth the price of admission. Portraits of punks'n'folks, alive and dead. Drunken and twisted fantasies. The only photocopy of the Beatles portrait that I drew in 1967 is in that journal. Imagine using a 6B pencil for 230 hours drawing your heroes. The Xerox is disintegrating so should be scanned. My neighbor down the hall just bought a scanner and he is turning his apartment into a petri dish so perhaps he has lost his mind. Many folk are adopting the petri-dish approach to their environment. Then Dhani Harrison plays a George song in YT - the Inner Light, which I've been singing and playing for 54 years. Why do folk turn their homes into giant petri dishes? Is it a Fox news thing?
There is no explaining the acts of irrational individuals, B.
Beautiful!!!
Thanks, WTD. I still have this amp and consider it to be one of the best I ever built.
Wow! I really really like that!
I have zero skills in electronics, although i can make a nice cabinet.
Thing is, i need a good little bass guitar amp like that.
I have no idea how to make an amp like that suitable for lower volume bass. But the look of it is just beautiful, and the controls are all i want, a volume, tone, off/on.
Guess i need to do more research and learn how to make a small bass amp like that.
Man that beastie sounds cool though!
Thanks so much, Book. Good luck with your project.
Sweet amp. Great job. I really enjoy your videos and watch them one after another so You have one more happy subscriber :)
Thanks so much, Nusior. This is probably my favorite of all the amps I have built. Once I found a really good, NOS 6N7 for it (no easy task) it just "took off" with tone and volume that equal most (if not all) of my vintage amps. Rusty and I really appreciate your time and interest :) ^. .^
ah.very interesting..nice build .One of my radio/phono consoles (RCA VRA 121 ) uses a 6SC7 as phase inverter., and I have an old 6L6 push/pull amp that I am rebuilding that actually originally used 2 6N7's ,but I am rebuilding it from a schematic that uses 6SJ7's and 6J5 asphase inverter. I think it would be interesting to see how different an amp like this might sound using two- four 8 inch or 10 inch speakers as opposed to one 12 or 15 inch speaker
Very cool! I may be turned nah an 50’s Olsen hifi into one of these for someone since it has mostly the same tubes. A woodworking friend is going to build a replica Woody Art Deco cab for it ,too. I was wondering if the tone pot might be better off (and safer) somewhere else,as well.
Good luck with your project, William.
I love the baffle in the style of your 1947 National. Great touch!
The speaker basket seems to resemble a Magnavox, but I have seen that speaker code on a driver from a "Califone" record cabinet... that speaker's basket looks like a Utah... This may be more confusing than helpful, but I hope it helps!
I also wanted to mention the control scheme... I think someone else made a comment regarding the 5E3... I recently repaired a gentleman's 1954 Fender Pro amplifier. The controls were exactly the same as this and the 5E3, where the volume are interactive... a very peculiar circuit indeed.
Regarding the Pro Amp, it was a real treat for me being the oldest piece of guitar gear I've ever played through, let alone had the pleasure to work on. The original Jensen P15N was even there and in spectacular shape to boot! The worst offense was the blonde(ish) tolex somebody used to cover up the (probably tattered) tweed - there were traces of some unidentified pink goop (contact cement?) between the two layers. At least the original grill cloth was still there (under a layer of modern poly-oxblood) - a little bit of stretching and it was almost like new! I wish you could've seen it.
Greetings, Britt, and thanks for the kind words re the speaker baffle. The speaker code is 583525, and according to my list, 583 indicates Magnavox....probably the 25th week of 1955 (not 65, I would guess, based on the style of Alnico magnet). What a shame that someone covered over the original tweed on the early Pro amp, especially after slathering it with pink contact cement :( I always cringe when I see these counterproductive "repairs".
Doug have you thought of building an organ speaker as we discussed before Jim Hermansen
I really haven't had a chance to think much about it, Jim. Things have been rather hectic.
Do you have the parts list for this amp. I would like to find some of these vintage parts and try building one. I find your videos very interesting and I thank you for that. It is great, that you share your knowledge.I have some basic electronic education and your videos have made me interested in electronics again. Thanks
Greetings, 330, and thanks for the kind words. I have no plans or parts list, other than a schematic I downloaded on the Internet. When I build, I generally do so without plans, simply making things up as I go.
I can tell you that I used the power transformer, output transformer, and filter choke (I installed one, even though the original Model 26 didn't use a FC) from a Deluxe Reverb amp. You could also use the PT and OPT from the 5E3 Deluxe if you wished. I also moved the tone control from between the output tubes and OPT to the volume control circuit (just after the 6SC7). I encourage you to build one of these jewels for yourself.....the tone is exceptional !! Good luck.
Very cool UD! Sounds very similar to mine but I’m I’m trying to eliminate some 60hz hum. May just be coming from the power transformer but I’m hoping I can fix it by finagling the heater wires. I’m running out of options pretty quickly! Hopefully I’ll figure it out. It’s not HORRIBLE but it just bugs me.
Thanks, William. Good luck tracking down the hum source.
Another great video Doug! Some beautiful work here (ya gotta like a guy who designs his own chassis and cabinet)! Walking through the circuit, I'm reminded of some similar circuits in other old amp designs that seem to use the grid leak resistor but omit the grid stopper resistor in the single "Mic" input but do the opposite in the "Instrument" input (i.e. have grid stopper but no grid leak resistor) - like we have here in the 26. If you have time for a question - what's up with that? In any case, thanks for these videos - I've learned more from them and you than a lot of years of reading books!
Thanks, Richard. I believe the reason is that instrument, i.e. guitar, input signals are much stronger than microphone signals, thus the grid stopper may be needed for them, but not for the microphone input. In my revised schematic for the Modified Model 26 Deluxe (see link in video description), both inputs have identical grid stoppers, but the grid leak resistors are quite different, to provide different input impedance and gain.
What a Craftsman, nice job Uncle D, do you sell any of your amps? Nice work!
Thanks so much, Ron. Yes, I occasionally sell my vintage and home-built amps. If you are interested in any specific ones, please send me a personal message and I will provide the details, like shipping and price.
Uncle Doug Great thanks so much, keep up the good work.
Gavin, I gather that you don't play the guitar and thus have no use for the amp......so, other than sending it to me :), you might consider listing it on Craigslist, if you are near a big city, or on Ebay. They are quite rare, but appeal to a limited group of collectors/musicians (like me and a lot of subscribers to this channel) who tend to favor older vintage amps. Working or not, it would be of great interest to one of us.
Very nice build! Do you sell your amps?
Yes, I do, Ric. From time to time I do sell a vintage or home-built amp.....to make room for more :)
Many of these early amps seemed to have a instrument, and a mic input. Was this the evolution of the high and low gain inputs or bright channel input?
It was generally for microphone (singing) and instrument (lap-steel guitar). The impedance had to be different to match each input.....but people soon discovered that they could plug a guitar into the microphone (louder) input and make more noise.
What is the make of that 5Y3? I don't think I've ever seen a tube base printed like that before.
I is an unusual tube, D20. It is labeled "Videos Made in USA......Used or Seconds Guaranteed".
Hi Doug, can I use 12ax7 with adapter instead of 6SC7 as it is difficult to find these tubes especially here in Australia?
I wasn't aware they had such adapters, Petar. If they are available and from a reputable source, I see no reason why you couldn't use it. Is it prohibitively expensive to simply order a couple 6SC7's from the US ?
Hi Doug....I continue to be impressed by this build. Great schematic mods. Does the dotted lines in the circuit represent a shielded wire? Also, I see a capacitor connected to the fuse in the video and the original schematic, however, it isn't present in the updated schematic. Moreover, I would think that this is a death capacitor but you have a three prong cable. What is that capacitor used for? Thanks! Bart
+redfishbum Thanks, Bart. This ended up being a really nice amp. If the dotted lines are on both sides of a solid line, then they indicate a shielded cable. The "death cap" helps to eliminate any electrical noise that comes in with the 120VAC in the primary circuit. They work with both two (if the plug is oriented correctly) and three-wire power cables.
+Uncle Doug Thanks! I knew you had a reason.
Uncle Doug. Love your videos, I'm learning a lot from them. Can you explain why the grid of the 2nd preamp tube connects to those resistors (10K, 250K)? Is this just another amplification stage after the first half of this tube or something else? What do you call this stage?
+Dan Cullinane Thanks, Dan. Actually, the 6N7 is a Paraphase Phase Inverter, which provides an in-phase signal to one of the output tubes and an out-of-phase signal to the other one, so they can provide the push-pull signals for the output transformer. I explain this better in my video on Phase Inverters.
Very nice !! But you've got me stymied !! Where did you hide the 16 uF Power Caps ??
I borrowed a trick from the Bassman and put them all on the rear of the chassis, near the power transformer, facing the speaker. If you look at photos of the amp during construction (posted on my Uncle Doug's Vintage Amps Facebook page) you will see them.
Uncle Doug Got it !! Very nice !! What a sweet - clean construction !! smile !
Thanks, Donald. I was very pleased with the way it turned out :)
Hey Uncle Doug....I've been kicking around another build in the future (crazy me but I absolutely love the Supro Clone that I cloned after yours!).....I've been looking at alnico speakers on eBay. Thoughts on a single 15" as you have here or twin 10" or 12"? Overkill for this design? Thanks!
You're welcome, Bart. I'm torn between both of your options. Nothing conveys bass and power any better than a big 15" speaker......but multiple smaller speakers can be really impressive too. I recall the brownface Concert amp I restored a couple years ago, putting an orphaned chassis back into an original 4 x 10" cabinet with new, good quality speakers. The moment I struck a chord through it, I felt shivers up the spine. It was spectacularly nice. I think if you are limited to two 10" or 12" speakers, I would do something unusual and use mismatched speakers, i.e. one Alnico and one Ceramic. You would have the best of both worlds.....and a truly rich, full sound.
Uncle Doug Thanks for the reply my friend! I might give e-bay a try at finding some vintage speakers. Thanks again! B
Hi Doug,
What type of phase inverter is used in this build. I want to say a paraphrase of some kind, but I’m not sure.
Thanks
HR
If you did, I would agree with you, Howard.
Uncle Doug , Thanks.
I have some parts left over from donated and abandoned amps. This build might be the template I use.
Best regards,
HR
@@howardrose8481 Good luck with the project, Howard.
Uncle Doug , when you build an amp how thick of plywood do you use on your baffles?
I use 1/2" birch plywood, Tim. I get it from either Lowe's or Home Depot.
Uncle Doug thanks:)
Is there any books on tubes basic functions??
Yes. Gerald Weber wrote several books that are generally available on Amazon.