Thanks, SI. These older amps are getting almost impossible to find, other than in collections, guitar shops, or someone's closet (extremely rare). Once they're checked out and repaired by a knowledgeable tech.....and not subjected to a lot of physical abuse.....they are quite reliable. You're right about the sound. To me they're like candles, with a warm mellow glow, rather than modern amps, especially solid state, which tend to be more like fluorescent lights....if that makes any sense.
You´re awesome Uncle Doug, i don´t know what's better, your videos, skills or your witty humor on the commentary of the video, it cracks me all the time. You should be on TV or Radio, don´t stop making videos, you're one of the best "youtubers" out there.
Join the crowd, Cat. Hardly a day goes by that I don't discover something which contradicts my previous notions. Since 5Y3 tubes were readily available in 1947, and you would think that using one tube would be easier and cheaper than using two, I'm not sure what benefits were gained from the dual rectifier set up. As I said in the video, it's a strange circuit, but it does sound quite nice.
The refurb on the National amp is extraordinary. If only I could find a plastic surgeon who has as much an eye for detail and cosmetic beauty as you have for amps. . .I would look great, too! I enjoyed the video thoroughly.
I LOVE the work you have done to this amplifier. I only started really diving into the circuits of tube amps in the past year but when you said loctal tubes I got very very excited. You did a fantastic job and it sounds great. Thanks for the time, effort, and comedic narration you put into this video and restoration.
Thanks back at you, Aaron. I really appreciate your kind words. Loctal tubes are truly a weird branch on the tree of vacuum tube evolution, but they sound great.....and offer the additional advantage of staying in their sockets come hell or high water. I wish they were still available for those top-mounted chassis in which the tubes hang up-side-down.
OK on the links, if you wish. It's hard to judge from a distance, but I will offer my opinions. Also, I'm not sure if you can send links by comment or message.
Beautiful restoration,Uncle Doug!I have worked on older,vintage amps' and it's a real task deciding what to do and not to do?This turned out totally classic looking!The sound is incredible and nice playing!
Thanks, Cat. The amp does have a great tone......with no modification other than a little delay. Re the dual rectifiers, I know that modern amp builders like Mesa use this method to ensure sufficient current flow (i.e. to prevent "sag") to the amplifying tubes. The 6X5 tubes were rated at only 70mA each, whereas 5U4GB's are rated at 275mA and 5Y3's at 125mA....so it took two 6X5's to produce the same current as a 5Y3. It would have taken 4 of them to match one 5U4GB.
You are like Leo Fender: not a great musician, but appreciate good music (and play a bit), and your love for music and electronics drives you to love the instruments used to create music, and lovingly heal them back to health. We dig it..!
i really dig the fact that you learned guitar in an era JUST prior to me. (this is not a dig at BOTH our advancing years :) ) You seem to have come up during the surf craze and I came up JUST after, when more bending and a slightly harder edge entered the scene via post early beatle invasion and hendrix. I do like the backing track and per usual, your channel is TOP drawer! Thanks as always. Bruce (1947 Chief from FB page recently).
Thanks so much, Bruce. My first guitar was a Harmony acoustic, back in the early 60's. I do recall trying to play along with the Ventures from time to time :)
That was really a special rebuild!! I also liked your new(at that time) demoing technic.. you asked.. I also believe that’s how the amp was meant to be played.. and you brought it back from it’s hard hard past life.. I’ll call it “The Phoenix Project”... amazing talent and professionalism!!
The schematic is tough to find and a little hard to read. I just added its location to the description of this video. To replace the electrodynamic speaker, you must first replace the missing field coil with a (high-wattage) resistor of equal resistance, and then connect the voice coil wires to the terminals of the new, permanent-magnet speaker.
To my knowledge, loctal tubes were made for car radios in the 50s-60s. WW2 vintage equipment for military use had separate spring clamp wires that went over the (usually metal) tubes.
If you'd like to see one of these amps in absolutely MINT condition, there is one currently listed on Ebay at a substantial price. Do an Ebay search for: 1946/47 Valco
Thanks, Charles. I agree completely. These amps were built at a very significant time in our country's history.....when America led the world in manufacturing and design. Those were happier, simpler times. I miss them.
Hello , Uncle Doug , Brilliant video ! Now that amp sounds smooth like a wet Sunday afternoon with rain drops running down window pane. Going through your record collection with a pint of beer not a worry in the world. Beautiful sound . Thanks again !
You're a poet at heart, DD. Thanks so much for the kind words and verbal artistry. It's raining here as we speak, and I suddenly have a strong desire to guzzle some beer and root through my old vinyl albums :)
trillriff-axegrinder Thanks so much, TA. I posted two other videos featuring side-by-side comparisons of nine and twelve different vintage amps....all in this format. Please check them out if you have the time.
That looks cool, great job! I like the cabinet, ventilation holes and the controls. Loctal tubes in a guitar amp,wow ! 1940's Philco radios used them ! I heard they were invented for use in car radios to reduce vibration..and higher frequency capability...I have seen many radios with 2 rectifiers ,I actually have a 1950's Philips radio/phono that has all miniature tubes and uses 2 6X4 minature rectifiers.(2 6AQ5 output)..I have to rewind the power transformer in that one.!
Yes, it's my understanding that the Loctals were an attempt to resist vibration. They do tend to stay, quite securely, in their sockets. Re the multiple rectifiers, if you check the DC output current capability of the 6X4's and 6X5's, it's so low (70mA) that a chassis with multiple amplification tubes would require two of them (at least). I still can't figure out why a single 5Y3 or 5U4 would not have been preferable.
by color I mean like a flavor, tang, Great example : Carlos Santana playing the singing guitar solo in "I'm Feeling You", but still the simplicity of tone like the slap guitar scene in the movie August Rush. Bright, sweet, aching, clear beautiful, fun. Thank you for doing something so wonderful as this collection of time to a lost generation
Holy Moly. Who in their right mind would have done anything with this other than toss it in the nearest dumpster? Answer... nobody. Which is why the world is a better place for having the clearly unhinged Uncle Doug. Wow! Less a restoration than an inspiration to create a work of art. Respect.
WOW, what an amazing sounding amp, well worth your efforts Uncle Doug, and the sound testing format works well. looking forward to lots more video`s. Thank you for your effort. Dave.
Thanks, John. I have posted a couple videos on my channel featuring a comparison of several different vintage amps, including this one. You might find these videos interesting.
If you would want to make it all loctal: 7A4 or XXL to replace the 6J5, 7C5 output tubes and 7X4 rectifier tubes. The 7B4 is a loctal equivalent of the 6SF5.
I was sickened when you showed the actual condition of the unit; Radio Shack Speaker, oh lord! regardless, you did a fabulous job on the restoration of the National vintage guitar amp. "Amazing"
+DwightMS1 Thanks for the flattering comparison, Dwight. I restored antique jukeboxes for many years, sometimes starting out with a pile of kindling wood and seemingly-junk metal, so this was actually a fun project. Glad you liked it :)
Doug you are an artist. Love the two tone look and maybe it looks different in person but i find that grill cloth quite tasteful.Way to raise the dead.Sounds as good as it looks and the demo was killer loved the backing track.
Hi Doug, What a great job youo did resurrecting this old amp... it even sounds good (your playing on this is part of that good sound). I noticed that you mentioned that there were two rectifier tubes on this amp, and that was a very rare thing. I have a Fender '57 Tweed Twin (low power... but the more recent reissue, which is basically the same amp. All hand wired (and priced accordingly if you can find a new one, but mine was used.) The amp also has a pair of rectifier tubes (GZ-34) which was a surprise... It's rated at about45 watts, the same as the tweed '59 Bassman (which has only one rectifier tube). Interesting... Also, I can't help but notice that the speaker grill opening on the front of this amp, if turned 90 degrees, forms a stylized "N" (for National?) I'm surprised to note that the folks at National never noticed this...
+Bill Daniels Thanks, Bill. I'm not sure why they would use two low-output 6X5 rectifiers, when it would be easier to simply use one 5Y3 or 5U4. Maybe they had a bunch of 6X5's laying around, or no power transformers with a 5VAC output. They did miss the boat by not rotating the grill cutout 90%.
Amazing video and expertise Uncle Doug!!! A whole lot of TLC I'm not so sure most of us would be willing to put into something in this condition..Thanks for all the informative videos!! John
Thanks, Mark. I got this amp in a group purchase and initially gave it little hope.....but it responded nicely. I also found the Loctal tubes to be interesting.
Loctals are another piece for the history museum. Most of them lived on a few years later in common octals such as... the 7C5 is a 6V6gt, the 7F7 is a 6SL7. Have you run into any 12 pin Compaction Tubes? I had one in an old Ampeg Bass Head a few months ago. They were designed for Color TV's and there would be 3 triodes or 2 pentodes. I've got a box of them on the shelf so I made a neat little 3 watt practice amp out of one just for giggles.
Loctals are rugged tubes, Mark. I mourn their passing. I have read about Compactrons and find them to be very interesting. The idea of building a one-tube SE amp or a two-tube DE amp is intriguing.....definitely on the list for future projects.
It sounds pretty good. I used a fender reverb driver tranny that sits on top of 2 of the triodes to an 8 ohm 10" jensen mod speaker. I used the 3rd triode as the pre-amp with a 120k plate resistor and 1k5 for the cathode with a 10uf cap. There is no volume or tone. You use the guitar for that. I'm pleased with the result. I'm thinking about building a vintage cab for it... Which cab are you fond of?
After some study of the RCA Tube Handbook, the advantage of two 6X5's becomes apparent. 6X5: filament current 600mA, DC output current 70mA. 5Y3: filament current 2 Amps, DC output current 125mA. With two 6X5's you get more output current (140ma vs 125 mA) and only draw about half (1.2A vs 2.0A) the filament current of a 5Y3. The 6X5's are MUCH more efficient.
I know this is an old video but truly amazing work on this one doug! And that sound check was tasty. I think my dad and I are a lot more like you than I'd previously thought. Not only do we breed and have a passion for Australian native parrots as well as a host of other birds, vintage cars and motorbikes have always been top priority in our family and anything vintage guitar related sits quite nicely as well :). I've said it before and I'll say it again love the videos and keep up the great work.
I may well try to do it both ways. The only problem I run into is the length of the videos. I worry that if they are too long, people might lose interest, so I try to moderate the running time. The guitar input is only slightly altered for this video, using exactly the same settings I use when personally playing this amp, and virtually all the others. I don't go in for heavy effects.....it does destroy the natural sound of the amp.
@11:53 we see "Amphenol...Chicago" on the socket. I now work for the TMS division of Amphenol in the (Amphenol) World Headquarters building in Wallingford, CT!! It looks like they used to be in Chicago in 1947(?) . Maybe it was a manufacturing facility back then. I'll have to look into that. Interesting.
You're right, JL.....I never noticed that before. The sockets are probably military surplus, so you might check to see if your company was involved in providing electronic components during WWII. Some Loctal sockets were also used in automobile radios, so that would be another area to investigate.
Liked the dinner music,really.Fantastic restoration and sounds great.Believe it or not,Radio Shack makes a pretty decent sounding speaker.I put one in a Fender Champ to keep from blowing the original speaker with pedals.It had very good clarity and nice gain
No, I used razor blades to slit and fit the material together in and over the corners, like a geometric puzzle. I believe the two 6X5's were necessary because each is capable of only 70mA, while a single 5Y3 can flow 125mA. It makes no sense from an economic standpoint, since double 6X5's and sockets HAD to cost more than a single 5Y3. Maybe 6X5's were cheap and readily available after the war and it made sense at the time. I have never seen another chassis like this.
Hi Uncle Doug, When you were first describing this amp and mentioned throwing it in the dump, i think the dump would have thrown it back. :) Seriously, the amp now looks and sounds great. Well done.
Wow, what a nice rebuild! If i found this, i simply would have taken out the chassis put in a head style case and dumped the cabinet. You have done a wonderful cabinet work! It may have some features not sen here, as the output tubes are transformer driven you can run it with grid current and very high drive levels. You may discover someday that if you running the Amp "all the way right" that it might have a very warm and hot overdrive. This is what only transformer coupled Amps can do.
Thanks, TC. I really like these circuits in which a center-tapped transformer provides phase inversion for the output tubes. Wurlitzer jukebox amplifiers used this same method (see my video) and, as you predicted, the result is really warm tone with strong bass.....ideal for jukeboxes (and old National amps :)
It´s because if the grid is coulped via FilmCap and a rather high resistorthere is always a delay due to dis- and re-charge the cap. This affects the tone and is the cause for some other side-effects if the resistor value of some negaive grid bias is not calculated probberly or choosen according to the datasheet... This can be totally ignored/neglected when a transformer is used as the phase splitter. As one can feed the neg grid bias via the center tap and the grid is beeing diven by a very low impedance souce. Even the negative grid bias is of low impedance. This leeds to a very good control of the tube and resulting a a very clear and linear tone...
Wow... Excellent Work! An eight year old video but still has Great Content and your signature off-the-cuff Hilarious commentary, the mark a True Consistent Professional! This amp's tone sounds Great! Awesome Video! Enjoyed it Thoroughly!! --Jason ✌🏻&❤️
Wow, i have lots of those tubes with the pin that clicks in. They were used and manufactured for a very long time in my country(nowadays czech republic, czechoslovakia back then :) ) I think we even had like a EL 34 tube with this kind of a socket.
+vojtasTS29 The Loctal tubes were very popular for a short period of time, right after WW II, then quickly died out. In my opinion, they are very rugged, good quality tubes that provide great service and tone.
I totally get the candle. Warmth fills the soul and the room despite how tiny the flame, but a florescent light is crisp, functional, cold. I've felt Light, colors, tastes, sounds share a similar feeling since I was a baby. My dream amp is a Carlos Santana "color" but the full life of this amp. Do you mind if I send you ebay links to some amps I just saw?
hi doug, that sounds sweet, great job again. them loctals i got a early 1951 bth mix power amp, well its got 8 ef50s 2 on each input, the outputs 4 6F6 small 6v6 got some wallop realy. yeah jam a long with doug, great idear, nice reverb or the room? great
"looks like a cat just backed up and sprayed it" .... "I don't blame him, I was tempted to do the same thing" ... I freaking literally laughed out loud at that one ....
Outstanding narrative and videotaping.I would never believe that great sound & tone would come from an amp like that. Please inform us of the guitar(s) you are using .
Yes, I do believe that Matsumoku made the Aria instruments.....which are generally of high quality and rather desirable. I'm not sure about the Yamaha, I thought they made their own. You could try automotive rubbing compound on the lacquer finish of the Yamaha. If the clouding is superficial, it will rub off. If not, you would have to strip the lacquer and replace it.
Thanks, 2005, for your very kind comments. This poor amp had been so horribly abused, bringing it back to life was both a challenge and a pleasure. It was almost like taking home a sick, stray dog and nursing it back to health......they always make the best (and most loyal) pets :)
Output transformer NAILED to the inside of the cabinet - you just don't get craftsmanship like that any more!!!! OK, so she won't bear close inspection in terms of original condition, but you've rescued something very precious and she sings again. Great job and compelling viewing - love your dry sense of humour too.
Yes indeed, Stony, the use of big nails to hang vital components always distinguishes a "true artisan" from the random gaggle of incompetents.....and there is nothing like a heavy dose of cat urine AND a reeking rat's nest to provide that "special" vintage ambiance. All that was missing was a black widow spider's nest to complete the Trifecta :) Which reminds me of a joyous experience many years ago, when I repaired clocks for local antique shops. I was working on a "grandmother" clock from Louisiana in my workshop, and laid the cabinet on it's back to facilitate disassembly. While working, I noticed some motion out of the corner of my eye.....and watched in horror as as some sort of "swamp tarantula" the size of a wharf rat crawled out of the cabinet. Before I could get a 2 x 4 to subdue the beast, it disappeared into the bowels of my workshop. This was B.R. (before Rusty), who would have (no doubt) killed and eaten it on the spot......so for several months thereafter, I had to stop work every few minutes and check to be sure nothing was crawling up my leg. Ah, the joys of restoration :)
What with all these Vintage amps I thought you might appreciate my Leather "Steamer Trunk" Corner protectors. Have a look.Guitar Amp Cabinet Video Export 2
Hey Uncle dog I love your video and I have the same amplifier that you are showing in the video mine is in good shape the outside doesn't look too pretty but nothing is beat up or tore up and everything seems original, so it needs a cap job and for the most part it has plenty of power and sounds actually pretty good but all the capacitors are old and wore out and bubbly looking so I was wanting to see if you could send me a link or a PDF file of the schematic thanks for any help keep up the good work.
Thanks, Ron. I have already posted photos of the original schematic on my FB page: Uncle Doug's Vintage Amps. You can find it there. Good luck with your project.
Nice tone on your final refurbish. You could probably sell that vintage Radio Shack speaker on ebay. In addition to the high dollar price tag that this brand demands, I would imagine the succulent allergy-attack-inducing bouquet of mildew, with an aftertaste finish of aged-in-pine-cabinet rat urine, is a feature that the new relic'd VintageOldStock speakers simply cannot accurately replicate.
Bravo! I do this kind of work too, but you are beyond me. Sounds and looks like a million bucks. Your approach to video is exemplary. My one critique would be to say not to poo-poo the Realistic speaker too much. Yes it's incorrect; yes it's ruined, but I'd bet dollars to donuts that when brand new, it was a good speaker, maybe a great speaker. Either way...good show.
Carl Rudd Thanks so much, Carl. Rusty and I are glad you enjoyed the video. Our criticism of the Realistic speaker was motivated primarily by just how visually wrong it was for this amp.....not that it was an inherently bad speaker.
Pretty nice playing but I really wanted a comparison demo of the mic and instrument inputs. The amp came out beautifully and I think the sparkle burlap is amazing. Do you ever run into a situation where the output transmixer is just so weeny that you beef it up just a tad? Thanx for another great vid and... cheers
The only difference between inputs is the overall gain, Jonny......they sound the same, only one is louder. I have since changed the grill cloth (sorry) and sold the amp :( You're right.....the OPT is inadequate for the power of the amp.
I haven't seen any military equipment with Loctal tubes. Loctal tubes were only used widely by a few equipment manufacturers, most notably Philco, which used the tubes in many table radios. (Wikipedia) I know that Sears used then in a number of their 1940s hi-fis.
Every time I watch one of these restoration vids I get mad at myself for letting my 3 old amps go !One was at least a fire hazard if not explosive device but the reverb was awesome sounding!
Uncle Doug youre right about that!The guy at the little repair shop said it would cost way more than they were worth to fix so I gave the to some body else to see what he could do and they were never seen again!The newer one was a little Dean Markley practice amp that had a beautiful range for its size ...Guess Im gonna go lookin!
Amp restoration can get a little pricey, unless you study and gain the skills to do it yourself. It's also much more rewarding. Good luck with finding a nice project.
Uncle Doug Oh,Im not gonna touch the insides of one of these things! I reluctantly change out an electrical outlet in my house from time to time!But I appreciate your expertise in these matters and especially liked the explanation of the inner workings of the speaker voice coil.Thanks!
Thanks, SI. These older amps are getting almost impossible to find, other than in collections, guitar shops, or someone's closet (extremely rare). Once they're checked out and repaired by a knowledgeable tech.....and not subjected to a lot of physical abuse.....they are quite reliable. You're right about the sound. To me they're like candles, with a warm mellow glow, rather than modern amps, especially solid state, which tend to be more like fluorescent lights....if that makes any sense.
You´re awesome Uncle Doug, i don´t know what's better, your videos, skills or your witty humor on the commentary of the video, it cracks me all the time. You should be on TV or Radio, don´t stop making videos, you're one of the best "youtubers" out there.
Thanks so much for your very nice comments, Mr. D. Rusty, Jack, and I really appreciate them :)
I'll second the affection for your humor. :)
Join the crowd, Cat. Hardly a day goes by that I don't discover something which contradicts my previous notions. Since 5Y3 tubes were readily available in 1947, and you would think that using one tube would be easier and cheaper than using two, I'm not sure what benefits were gained from the dual rectifier set up. As I said in the video, it's a strange circuit, but it does sound quite nice.
The refurb on the National amp is extraordinary. If only I could find a plastic surgeon who has as much an eye for detail and cosmetic beauty as you have for amps. . .I would look great, too! I enjoyed the video thoroughly.
I LOVE the work you have done to this amplifier. I only started really diving into the circuits of tube amps in the past year but when you said loctal tubes I got very very excited. You did a fantastic job and it sounds great. Thanks for the time, effort, and comedic narration you put into this video and restoration.
The amp looks and sounds great. The delay sounds nice and the playing sounds good too.
Thanks so much, Henry. Coming from a musician of your skill and experience, favorable comments like this mean a lot. Thanks for watching :)
Thanks, I really appreciate your kind words.
Thanks back at you, Aaron. I really appreciate your kind words. Loctal tubes are truly a weird branch on the tree of vacuum tube evolution, but they sound great.....and offer the additional advantage of staying in their sockets come hell or high water. I wish they were still available for those top-mounted chassis in which the tubes hang up-side-down.
OK on the links, if you wish. It's hard to judge from a distance, but I will offer my opinions. Also, I'm not sure if you can send links by comment or message.
Thanks, CP. I appreciate your input and will definitely keep your recommendations in mind.
Thanks, Henry, I really appreciate your visits to my channel and your kind words.
Beautiful restoration,Uncle Doug!I have worked on older,vintage amps' and it's a real task deciding what to do and not to do?This turned out totally classic looking!The sound is incredible and nice playing!
Thanks so much, Charles. I'm really glad you liked the video and the amp.
You're welcome, SI. I can tell you are a poet at heart......
Thanks, Cat. The amp does have a great tone......with no modification other than a little delay. Re the dual rectifiers, I know that modern amp builders like Mesa use this method to ensure sufficient current flow (i.e. to prevent "sag") to the amplifying tubes. The 6X5 tubes were rated at only 70mA each, whereas 5U4GB's are rated at 275mA and 5Y3's at 125mA....so it took two 6X5's to produce the same current as a 5Y3. It would have taken 4 of them to match one 5U4GB.
You are like Leo Fender: not a great musician, but appreciate good music (and play a bit), and your love for music and electronics drives you to love the instruments used to create music, and lovingly heal them back to health. We dig it..!
Thanks, PhD. That pretty well sums it up :)
i really dig the fact that you learned guitar in an era JUST prior to me. (this is not a dig at BOTH our advancing years :) ) You seem to have come up during the surf craze and I came up JUST after, when more bending and a slightly harder edge entered the scene via post early beatle invasion and hendrix. I do like the backing track and per usual, your channel is TOP drawer! Thanks as always. Bruce (1947 Chief from FB page recently).
Thanks so much, Bruce. My first guitar was a Harmony acoustic, back in the early 60's. I do recall trying to play along with the Ventures from time to time :)
That was really a special rebuild!! I also liked your new(at that time) demoing technic.. you asked.. I also believe that’s how the amp was meant to be played.. and you brought it back from it’s hard hard past life.. I’ll call it “The Phoenix Project”... amazing talent and professionalism!!
Thanks so much, Luth. This was the most amp difficult restoration project I have undertaken. The 1485 in the recent video is second.
The schematic is tough to find and a little hard to read. I just added its location to the description of this video. To replace the electrodynamic speaker, you must first replace the missing field coil with a (high-wattage) resistor of equal resistance, and then connect the voice coil wires to the terminals of the new, permanent-magnet speaker.
You made a great job of restoring that amp,Doug. I think the speaker cloth is fine. Loved the sound from it and also your lovely warm guitar sound.
Thanks, Eddie :)
You really knocked it out the park.Love the details .Wanna run my hand across that beautiful covering.
Glad you liked the video, Stephen.
Well this just popped up in my feed 9 years later. Great job of resurrecting the Unwalking Dead Uncle Doug.
Glad you enjoyed it, Tom :)
To my knowledge, loctal tubes were made for car radios in the 50s-60s. WW2 vintage equipment for military use had separate spring clamp wires that went over the (usually metal) tubes.
Galfonz You may well be correct, Galfonz. Thanks for your input.
nice restoration on this old amp ,idk if i would have been able to go that far with it but thats why all love your projects
Thanks, Joe.
Great restore video. It sounds really sweet. Probably sounds even better now than it did originally when new in 1947.
Cheers!
Krang Gangs Thanks, KG. There's no way to know that for sure, but I am quite pleased with how it turned out.
Where else can you find such interesting subject matter along with humor and great music?
Thanks, John....high praise indeed :)
If you'd like to see one of these amps in absolutely MINT condition, there is one currently listed on Ebay at a substantial price. Do an Ebay search for: 1946/47 Valco
Thanks, Charles. I agree completely. These amps were built at a very significant time in our country's history.....when America led the world in manufacturing and design. Those were happier, simpler times. I miss them.
Sound fantastic! Beautiful tone, I feel like I'm in paradise. Awesome work.
Thanks so much, RS. Glad you liked it :)
Very nice improvisation U.D. ! A really nice melody ,,! The amp sounded very sweet with those fx you were using,! Nice job !
Thanks, GM.....we're glad you liked it :)
Hello , Uncle Doug , Brilliant video ! Now that amp sounds smooth like a wet Sunday afternoon with rain drops running down window pane. Going through your record collection with a pint of beer not a worry in the world. Beautiful sound . Thanks again !
You're a poet at heart, DD. Thanks so much for the kind words and verbal artistry. It's raining here as we speak, and I suddenly have a strong desire to guzzle some beer and root through my old vinyl albums :)
i like the new format,you have some impressive chops and this amp sounds just wonderful ,clean and full.
trillriff-axegrinder Thanks so much, TA. I posted two other videos featuring side-by-side comparisons of nine and twelve different vintage amps....all in this format. Please check them out if you have the time.
Fantastic. Another great job from Uncle Doug.
Thanks, B66 :)
Wow. Beautiful amp. That's the way it should have looked in the first place. Great sound check as well. Love these videos
Thanks, Brandon....glad you are enjoying the videos :)
You, sir, are a freakin magician of the highest order.Someone once told me "you can't polish a turd....", you have proved them wrong.Nice demo too!
Thanks, NF. Rusty and I used almost a whole can of Turd Polish on this amp. We're glad you like how it turned out :)
My gosh that sound so good, Uncle Doug.
Thanks, Dominic :)
That looks cool, great job! I like the cabinet, ventilation holes and the controls. Loctal tubes in a guitar amp,wow ! 1940's Philco radios used them ! I heard they were invented for use in car radios to reduce vibration..and higher frequency capability...I have seen many radios with 2 rectifiers ,I actually have a 1950's Philips radio/phono that has all miniature tubes and uses 2 6X4 minature rectifiers.(2 6AQ5 output)..I have to rewind the power transformer in that one.!
Yes, it's my understanding that the Loctals were an attempt to resist vibration. They do tend to stay, quite securely, in their sockets. Re the multiple rectifiers, if you check the DC output current capability of the 6X4's and 6X5's, it's so low (70mA) that a chassis with multiple amplification tubes would require two of them (at least). I still can't figure out why a single 5Y3 or 5U4 would not have been preferable.
by color I mean like a flavor, tang, Great example : Carlos Santana playing the singing guitar solo in "I'm Feeling You", but still the simplicity of tone like the slap guitar scene in the movie August Rush. Bright, sweet, aching, clear beautiful, fun. Thank you for doing something so wonderful as this collection of time to a lost generation
Your humor.....priceless!
Thanks, MS :)
Holy Moly. Who in their right mind would have done anything with this other than toss it in the nearest dumpster? Answer... nobody. Which is why the world is a better place for having the clearly unhinged Uncle Doug. Wow! Less a restoration than an inspiration to create a work of art. Respect.
Thanks so much, Bill. Somebody had to help this poor old girl out ;)
Looks fantastic Uncle Doug
Thanks !!
Great work!! I have a Silvertone am radio with the loctal tubes that im currently restoring..
Thanks FM. Those loctals are definitely odd tubes.....but they sound great :)
WOW, what an amazing sounding amp, well worth your efforts Uncle Doug, and the sound testing format works well.
looking forward to lots more video`s.
Thank you for your effort.
Dave.
+Dave Chandler You're welcome, Dave, and thanks for your very kind words. I'm glad you like the National amp and are enjoying the videos.
Another great video Unk Doug. Keep going. This is one of my favorite U Tube sites.
Thanks, TD :)
That's real sweet sounding Doug!
Thanks, John. I have posted a couple videos on my channel featuring a comparison of several different vintage amps, including this one. You might find these videos interesting.
If you would want to make it all loctal: 7A4 or XXL to replace the 6J5, 7C5 output tubes and 7X4 rectifier tubes.
The 7B4 is a loctal equivalent of the 6SF5.
Thanks, D20, but I think I'll leave it as-is :)
I was sickened when you showed the actual condition of the unit; Radio Shack Speaker, oh lord! regardless, you did a fabulous job on the restoration of the National vintage guitar amp. "Amazing"
+John Cunningham Thanks, John.....glad you liked how it turned out :)
Doug, you're like a guitarist's idea of "American Restoration," and I like both programs.
+DwightMS1 Thanks for the flattering comparison, Dwight. I restored antique jukeboxes for many years, sometimes starting out with a pile of kindling wood and seemingly-junk metal, so this was actually a fun project. Glad you liked it :)
Doug you are an artist. Love the two tone look and maybe it looks different in person but i find that grill cloth quite tasteful.Way to raise the dead.Sounds as good as it looks and the demo was killer loved the backing track.
Thanks for all the very nice comments. Rusty and I are really glad that you liked the video, demo, and the completed amp :)
Hi Doug,
What a great job youo did resurrecting this old amp... it even sounds good (your playing on this is part of that good sound).
I noticed that you mentioned that there were two rectifier tubes on this amp, and that was a very rare thing. I have a Fender '57 Tweed Twin (low power... but the more recent reissue, which is basically the same amp. All hand wired (and priced accordingly if you can find a new one, but mine was used.) The amp also has a pair of rectifier tubes (GZ-34) which was a surprise... It's rated at about45 watts, the same as the tweed '59 Bassman (which has only one rectifier tube). Interesting...
Also, I can't help but notice that the speaker grill opening on the front of this amp, if turned 90 degrees, forms a stylized "N" (for National?) I'm surprised to note that the folks at National never noticed this...
+Bill Daniels Thanks, Bill. I'm not sure why they would use two low-output 6X5 rectifiers, when it would be easier to simply use one 5Y3 or 5U4. Maybe they had a bunch of 6X5's laying around, or no power transformers with a 5VAC output. They did miss the boat by not rotating the grill cutout 90%.
Rusty does most of my demos.....he's been playing for about 63 (dog) years :)))
Amazing video and expertise Uncle Doug!!! A whole lot of TLC I'm not so sure most of us would be willing to put into something in this condition..Thanks for all the informative videos!! John
You're welcome, JT. The bigger the challenge, the greater the reward :)
A sweet resurrection... and a nice sounding piece of history!
Thanks, Mark. I got this amp in a group purchase and initially gave it little hope.....but it responded nicely. I also found the Loctal tubes to be interesting.
Loctals are another piece for the history museum. Most of them lived on a few years later in common octals such as... the 7C5 is a 6V6gt, the 7F7 is a 6SL7. Have you run into any 12 pin Compaction Tubes? I had one in an old Ampeg Bass Head a few months ago. They were designed for Color TV's and there would be 3 triodes or 2 pentodes. I've got a box of them on the shelf so I made a neat little 3 watt practice amp out of one just for giggles.
Loctals are rugged tubes, Mark. I mourn their passing. I have read about Compactrons and find them to be very interesting. The idea of building a one-tube SE amp or a two-tube DE amp is intriguing.....definitely on the list for future projects.
It sounds pretty good. I used a fender reverb driver tranny that sits on top of 2 of the triodes to an 8 ohm 10" jensen mod speaker. I used the 3rd triode as the pre-amp with a 120k plate resistor and 1k5 for the cathode with a 10uf cap. There is no volume or tone. You use the guitar for that. I'm pleased with the result. I'm thinking about building a vintage cab for it... Which cab are you fond of?
I like the old National and Oahu cabinets. I try to incorporate some of their design cues in my homebuilt amps.
After some study of the RCA Tube Handbook, the advantage of two 6X5's becomes apparent. 6X5: filament current 600mA, DC output current 70mA. 5Y3: filament current 2 Amps, DC output current 125mA. With two 6X5's you get more output current (140ma vs 125 mA) and only draw about half (1.2A vs 2.0A) the filament current of a 5Y3. The 6X5's are MUCH more efficient.
I know this is an old video but truly amazing work on this one doug! And that sound check was tasty. I think my dad and I are a lot more like you than I'd previously thought. Not only do we breed and have a passion for Australian native parrots as well as a host of other birds, vintage cars and motorbikes have always been top priority in our family and anything vintage guitar related sits quite nicely as well :). I've said it before and I'll say it again love the videos and keep up the great work.
Thanks so much, Bill. We are indeed kindred spirits.....even Rusty is of Australian ancestry :) Best of luck with all your pursuits.
I may well try to do it both ways. The only problem I run into is the length of the videos. I worry that if they are too long, people might lose interest, so I try to moderate the running time. The guitar input is only slightly altered for this video, using exactly the same settings I use when personally playing this amp, and virtually all the others. I don't go in for heavy effects.....it does destroy the natural sound of the amp.
@11:53 we see "Amphenol...Chicago" on the socket. I now work for the TMS division of Amphenol in the (Amphenol) World Headquarters building in Wallingford, CT!! It looks like they used to be in Chicago in 1947(?) . Maybe it was a manufacturing facility back then. I'll have to look into that. Interesting.
You're right, JL.....I never noticed that before. The sockets are probably military surplus, so you might check to see if your company was involved in providing electronic components during WWII. Some Loctal sockets were also used in automobile radios, so that would be another area to investigate.
thank you very much for the demo greetings jan
jan kolk You're welcome, Jan. We're glad you enjoyed the video :)
A truly heroic rescue effort!
+Arnold Rimmer Thanks, Arnold. I love challenges like this.....the end result (hopefully) justifies the (sometimes huge) effort :)
I was literally laughing out loud at your description of this beauty.
Glad you enjoyed it, Sting :)
I have one of these..still working on it.
Liked the dinner music,really.Fantastic restoration and sounds great.Believe it or not,Radio Shack makes a pretty decent sounding speaker.I put one in a Fender Champ to keep from blowing the original speaker with pedals.It had very good clarity and nice gain
Thanks so much, William. Over the years, I used many Radio Shack products and never had any problems with them. Indeed, I mourn their loss.
Really liked that sound check.
Thanks, Dan :)
UD: "I was feeling, uh, adventuresome so I decided to fix it up"
Me: you are a mad man.
Me +40sec: oh you beautiful beautiful man!
Glad you like the outcome, PM.
Love your grill designs!
Thanks, Steve. This one was original, but I do try to come up with unique vintage-style grills for the amps I build.
No, I used razor blades to slit and fit the material together in and over the corners, like a geometric puzzle. I believe the two 6X5's were necessary because each is capable of only 70mA, while a single 5Y3 can flow 125mA. It makes no sense from an economic standpoint, since double 6X5's and sockets HAD to cost more than a single 5Y3. Maybe 6X5's were cheap and readily available after the war and it made sense at the time. I have never seen another chassis like this.
Great sound check!! Awesome vid!!
Thanks, Kj :)
Hi Uncle Doug,
When you were first describing this amp and mentioned throwing it in the dump, i think the dump would have thrown it back. :)
Seriously, the amp now looks and sounds great. Well done.
Good observation, Donnie. It would be like Chuckie.......burn it, throw it away, ship it to Siam.......and it shows up back on your doorstep :O
P.S. Thanks :)
Wow, what a nice rebuild! If i found this, i simply would have taken out the chassis put in a head style case and dumped the cabinet. You have done a wonderful cabinet work!
It may have some features not sen here, as the output tubes are transformer driven you can run it with grid current and very high drive levels. You may discover someday that if you running the Amp "all the way right" that it might have a very warm and hot overdrive. This is what only transformer coupled Amps can do.
Thanks, TC. I really like these circuits in which a center-tapped transformer provides phase inversion for the output tubes. Wurlitzer jukebox amplifiers used this same method (see my video) and, as you predicted, the result is really warm tone with strong bass.....ideal for jukeboxes (and old National amps :)
It´s because if the grid is coulped via FilmCap and a rather high resistorthere is always a delay due to dis- and re-charge the cap. This affects the tone and is the cause for some other side-effects if the resistor value of some negaive grid bias is not calculated probberly or choosen according to the datasheet...
This can be totally ignored/neglected when a transformer is used as the phase splitter. As one can feed the neg grid bias via the center tap and the grid is beeing diven by a very low impedance souce. Even the negative grid bias is of low impedance. This leeds to a very good control of the tube and resulting a a very clear and linear tone...
WOW, I thought I had some basket cases around here! Splendid job Man.
+Jeff Brooks Thanks, Jeff :)
Great video, as always! Many thanks!
+SiliconSet You're welcome, SS :)
The circuit and tube complement are a bit strange, Francois, but once completed, it is a very nice, soulful amp.
Nice job
Wow... Excellent Work! An eight year old video but still has Great Content and your signature off-the-cuff Hilarious commentary, the mark a True Consistent Professional! This amp's tone sounds Great! Awesome Video! Enjoyed it Thoroughly!! --Jason ✌🏻&❤️
Thanks so much, J :)
That sounds amazing!
Thanks, Jack :)
Wow, i have lots of those tubes with the pin that clicks in. They were used and manufactured for a very long time in my country(nowadays czech republic, czechoslovakia back then :) ) I think we even had like a EL 34 tube with this kind of a socket.
+vojtasTS29 The Loctal tubes were very popular for a short period of time, right after WW II, then quickly died out. In my opinion, they are very rugged, good quality tubes that provide great service and tone.
I totally get the candle. Warmth fills the soul and the room despite how tiny the flame, but a florescent light is crisp, functional, cold. I've felt Light, colors, tastes, sounds share a similar feeling since I was a baby. My dream amp is a Carlos Santana "color" but the full life of this amp. Do you mind if I send you ebay links to some amps I just saw?
Nice Uncle Doug.
Thanks, Chris :)
hi doug, that sounds sweet, great job again. them loctals i got a early 1951 bth mix power amp, well its got 8 ef50s 2 on each input, the outputs 4 6F6 small 6v6 got some wallop realy. yeah jam a long with doug, great idear, nice reverb or the room? great
freak55beat Thanks, FB, glad you liked it. I think the reverb effect was provided by the "lively" acoustics in the room.
great sound mate, would record nice, the amp is alive
Thanks, FB. Glad you like it :)
Lovely job.
Thanks, Adam. The bigger the challenge, the greater the sense of achievement when it is completed :)
I think this much better ... That is got to be one of the nicest sounds of the amp ..,))) ... seems you bin practicin Mr. Doug ... )))
Thanks, AT :)
another cracking rebuild!!!
Sweet sound
TheOldgeezah Thanks, OG. Glad you liked it :)
"looks like a cat just backed up and sprayed it" .... "I don't blame him, I was tempted to do the same thing" ... I freaking literally laughed out loud at that one ....
Thanks, TG.....glad you liked it :)
Very nice... Great video content 😎
Thanks, Jean.
Outstanding narrative and videotaping.I would never believe that great sound & tone would come from an amp like that.
Please inform us of the guitar(s) you are using .
Thanks so much, Molson. My shop guitar is a 1979 Matsumoku Vantage V-695 Performer with MMK-45 humbucker pickups.
Yes, I do believe that Matsumoku made the Aria instruments.....which are generally of high quality and rather desirable. I'm not sure about the Yamaha, I thought they made their own. You could try automotive rubbing compound on the lacquer finish of the Yamaha. If the clouding is superficial, it will rub off. If not, you would have to strip the lacquer and replace it.
We like Uncle Doug!
That's great to hear, Mr. T. Thanks !!!
Thanks, 2005, for your very kind comments. This poor amp had been so horribly abused, bringing it back to life was both a challenge and a pleasure. It was almost like taking home a sick, stray dog and nursing it back to health......they always make the best (and most loyal) pets :)
Output transformer NAILED to the inside of the cabinet - you just don't get craftsmanship like that any more!!!! OK, so she won't bear close inspection in terms of original condition, but you've rescued something very precious and she sings again. Great job and compelling viewing - love your dry sense of humour too.
Yes indeed, Stony, the use of big nails to hang vital components always distinguishes a "true artisan" from the random gaggle of incompetents.....and there is nothing like a heavy dose of cat urine AND a reeking rat's nest to provide that "special" vintage ambiance. All that was missing was a black widow spider's nest to complete the Trifecta :)
Which reminds me of a joyous experience many years ago, when I repaired clocks for local antique shops. I was working on a "grandmother" clock from Louisiana in my workshop, and laid the cabinet on it's back to facilitate disassembly. While working, I noticed some motion out of the corner of my eye.....and watched in horror as as some sort of "swamp tarantula" the size of a wharf rat crawled out of the cabinet. Before I could get a 2 x 4 to subdue the beast, it disappeared into the bowels of my workshop. This was B.R. (before Rusty), who would have (no doubt) killed and eaten it on the spot......so for several months thereafter, I had to stop work every few minutes and check to be sure nothing was crawling up my leg. Ah, the joys of restoration :)
Uncle Doug
LOL - I never would have set foot in that workshop again - clearly you are made of sterner stuff!
OMG, i am laughing so hard at your evaluation of the original condition. You are killing me!!! Too funny!
Thanks, Mo......glad you enjoyed it :)
What with all these Vintage amps I thought you might appreciate my Leather "Steamer Trunk" Corner protectors. Have a look.Guitar Amp Cabinet Video Export 2
Very nice work, Greg. Definitely old world craftsmanship at its best !!
Looking for the Schematic...trynna find out the Capacitor Values. I would like to know how to do the Speaker Mod as well.
Hey Uncle dog I love your video and I have the same amplifier that you are showing in the video mine is in good shape the outside doesn't look too pretty but nothing is beat up or tore up and everything seems original, so it needs a cap job and for the most part it has plenty of power and sounds actually pretty good but all the capacitors are old and wore out and bubbly looking so I was wanting to see if you could send me a link or a PDF file of the schematic thanks for any help keep up the good work.
Thanks, Ron. I have already posted photos of the original schematic on my FB page: Uncle Doug's Vintage Amps. You can find it there. Good luck with your project.
Nice tone on your final refurbish. You could probably sell that vintage Radio Shack speaker on ebay. In addition to the high dollar price tag that this brand demands, I would imagine the succulent allergy-attack-inducing bouquet of mildew, with an aftertaste finish of aged-in-pine-cabinet rat urine, is a feature that the new relic'd VintageOldStock speakers simply cannot accurately replicate.
So true, A7. I considered making a Covid mask out of the urine-soaked cone, but couldn't resist the huge cash offers from vintage collectors.
Bravo! I do this kind of work too, but you are beyond me. Sounds and looks like a million bucks. Your approach to video is exemplary. My one critique would be to say not to poo-poo the Realistic speaker too much. Yes it's incorrect; yes it's ruined, but I'd bet dollars to donuts that when brand new, it was a good speaker, maybe a great speaker. Either way...good show.
Carl Rudd Thanks so much, Carl. Rusty and I are glad you enjoyed the video. Our criticism of the Realistic speaker was motivated primarily by just how visually wrong it was for this amp.....not that it was an inherently bad speaker.
Pretty nice playing but I really wanted a comparison demo of the mic and instrument inputs.
The amp came out beautifully and I think the sparkle burlap is amazing.
Do you ever run into a situation where the output transmixer is just so weeny that you beef it up just a tad? Thanx for another great vid and...
cheers
The only difference between inputs is the overall gain, Jonny......they sound the same, only one is louder. I have since changed the grill cloth (sorry) and sold the amp :( You're right.....the OPT is inadequate for the power of the amp.
I haven't seen any military equipment with Loctal tubes. Loctal tubes were only used widely by a few equipment manufacturers, most notably Philco, which used the tubes in many table radios. (Wikipedia) I know that Sears used then in a number of their 1940s hi-fis.
I believe they were also used in car radios, Steve.
The speaker field coil, as you mention worked as a choke. Is there room for a filter choke on the chassis?
NJPurling Yes, the absence of the field coil was compensated for in the amp circuit.
Every time I watch one of these restoration vids I get mad at myself for letting my 3 old amps go !One was at least a fire hazard if not explosive device but the reverb was awesome sounding!
gary h No matter how far gone they may appear, Gary, they can (and should) all be saved :)
Uncle Doug youre right about that!The guy at the little repair shop said it would cost way more than they were worth to fix so I gave the to some body else to see what he could do and they were never seen again!The newer one was a little Dean Markley practice amp that had a beautiful range for its size ...Guess Im gonna go lookin!
Amp restoration can get a little pricey, unless you study and gain the skills to do it yourself. It's also much more rewarding. Good luck with finding a nice project.
Uncle Doug Oh,Im not gonna touch the insides of one of these things! I reluctantly change out an electrical outlet in my house from time to time!But I appreciate your expertise in these matters and especially liked the explanation of the inner workings of the speaker voice coil.Thanks!
You're welcome, Gary. Best of luck :)
sounds real sweet thx
You're welcome, Fred.
sounds like heaven ,made me think about Frankie and Annette.
That goes back a long way, Richard, to the early days just post Micky Mouse Club on TV.