it was rad that you had the correct speaker for this amp. it somehow reminded me of my cool old timer neighbor who had an pristine antique Winchester mod 94 lever action made in 1896 in 32-40 a caliber that was very hard to find in modern days, he told me that he had owned it for a long time but never got a chance to shoot it witch was on his bucket list. i told him to give me a few mins to go forage threw my strange ammo collection. i returned with 3 full 20ct boxes of cartridges the boxes wer for the 32win spsl witch he pointed out to witch i told him to check the head stamp on the actual cartridge and he let out a gasp...yup i said their all 32-40 sp nos. he asked what i wanted for them and my reply was for him to shoot them all then reload the shells a few times and just enjoy the experience!
What you see on the scope at about 27:29 is classic crossover-distortion, suggesting that either the two output tubes aren't properly biased, or, they're worn-out, or, something isn't letting them operate correctly.
Valco nee 'Supro' made the kind of classic rock tone we came to appreciate on our 70s vinyl. These little amps sounded monstrous in the studio and truth be told, not too shabby in the garage or bedroom. Their early breakup and natural distortion from those, shall we say, inexpensive components Valco used are what made that tone!
Old amps like this have tons of character. This would be a great one to bring into the studio. Sure it sounds boxy in the video but mic'd up it would sound totally different.
It's so relaxing to see you at work on all those old amplifiers. I only work on my guitars electrically like swapping out pickups now and then and experiment with different switching ideas. But I keep way clear of high voltage appliances. Keep up the excellent work, love your channels as well as your work 🙂
This show just keeps getting better...the playing, that clip of JP showing the tele he got from JB and that little 6970 supro with the 12' speaker., the phone call to SRVs amp tech. So much info I may want to watch this one twice after I go check my national and my supro for the 550 code on the jensens
Hey Brad, greetings from Bulgaria! Your amazing videos are very interesting, educational and motivational! I want to thank you so much for it! You are super professional musician and intelligent equipment technician! My respects! Happy New Year 2023 to you, your family, friends, all the people around you and your followers here! :-) God bless you all!
I have what I’m fairly certain is the Montgomery Ward equivalent (so to speak) of this amp and I have to say returning it to an old ‘66 C12Q was really what brought the whole thing home. As nice as the newer Jupiter speaker has the previous owner had installed was-the magnet was just to big or something.
Dude I just love listening to you mess around playing the guitars ...the bonus is generally the old amps at that. Plus I learn a bit more about the good electronics each upload. Merry Xmas to you and fam Brad.
Everytime I watch your vids I get the itch to go out garage saling & hitting up resales shops!! Great job reviving that Orpheum, sounds decent even with the RS speaker! Thanks Brad!!
@@fredgarvin4482 It's an old school name for lacquer or any solvent based coating, clear to opaque. Lacquer, or dope, hardens when it dries, and would make the cone more stiff, effecting it's response.
Magnific! Love me some old Valco. Other than the handle, the construction techniques and materials are identical to my old Airline 62-9017a. For any would-be Santas out there, I could use an Airline logo to make mine complete. Great video - thanks, Brad!
@Timothy B . . I was thinking the same thing. I have the Airline 62-9017A as well. Man it's hard to find a whole lot of info on it. Mine needs work, and has probably been in someone's basement for decades. It does have the Airline logo, but it's missing the big V that goes on the front.
I recently took an interest in the old Bose Wave radios. The prices are still high. Apparently the capacitors need to be replaced, just like older guitar amplifiers
for whatever reason the algorythm has stopped telling me when you post new videos... thankfully i check in once in a while to those i follow and appreciate. Merry Xmas Brad! keep making the great content you make ! love from Canada
I'm gonna comment before even watching today all because of your thumbnail for this vid. RED ZEPPLIN roflmfao! Very clever bro and Merry F'n Christmas! lol
Found one about 15 years ago at a salvage store $50. Got new can cap new rec tube and a new after market handle and a grounded power supply. Ended up at around $450. traded it to a guy that swore it was a page amp. The guy that repaired it said Jimmy didint play or record with this amp.I told him. I made out like a bandit.
Hey Brad, As you obviously know, Valco made the same amp branded for several companies. My second amp ever was the Supro version. A few years after I had moved on to other amps, I read an interview with Page that had photos of the same amp but with a Gretch badge. Jimmy referred to it as having two 10" speakers. My little Supro also had two 10s and although his amp looked darker in the black and white picture, and had the different logo, they looked identical. Just my 2 cents to muddy the waters as to the brand of Jimmy's amp. Thanks again for all the great 'edu-tainment' you provide!
Good timing - I just bought the same amp --- but it's the VALCO AIRLINE version 62-9033A Appears identical. Mine appears all original. Has the original tubes - all RCA's including the 6973's. Original Jensen C12Q. Killer tremolo! Great to see your video to help me go thru the amp! QUESTION --- I'm thinking this is the same circuit as the VALCO Gretsch 6162, except the addition of reverb on the 6162? Thank you!
I've had a couple of these over the years... they really have maximum bark!! Some amps break up so gradually... but these really jump at you... I would have liked to hear it miked up well, to show what they do with a good mic or two catching that speaker and amp drive
Steve Wilson worked on my 65 Gibson Mercury amp last year,an old barn find,glad to bring this old amp back to life.Tell Catfish hi for me next time you see him for me Brad!😁
🤗🤗 That amp sounds really great!! Old pro tip, ....record with a small amp to get a huge sound.....good advice. Thanks Brad..Cheers and Merry Christmas!!
@@enigma1247 The engineer that mixed Def Leppards Hysteria album (plus others) showed me how their producer, Mutt Lange, got such huge guitar tracks. He opened the door to the vocal booth and sitting on a stool was a small guitar combo amp with a 10" speaker. it had great sounding distortion and drive and it was conversation loud. Stack a double handful of tracks with different tones: Voila!
The rubbing speaker coils: If the coils are not detaching from the cone, remove the dust cap, shim out the coil, inject a small amount of water and let it evaporate for a couple of days. No guarantees but it might work and save a recone job. Good luck.
Hey Brad. IDK, it could be me, but at about 36:40- 36:41, when you are putting the nut on the screw, I noticed rocking, of something. I don't know, if it was the spkr. rocking on a potentially slightly warped front panel, or if it was the entire amp, rocking on the bench. Wouldn't the first scenario, also warp the spkr. ring, when tightened, creating the cone rub?.. Like i said, it might be me, but there was a definite rocking motion, somewhere. And, if Steve replaces the spkr., it may cause the same issue, with the new spkr..
Brad, I'm a long time sub with ALL notofications turned on for your channels. I have not been notified of any of your recent videos. Just a heads up mate, hope you are all doing well and best wishes from Canada!
@@TheGuitologist yea, usually they just effect non sub interaction... seems they are going to a new level lately... it sucks as it effects people's ability to learn from your videos as well :(, keep up the good fight man, we're rooting for ya!
I have A/B’d the EH 6973 and RCA black plate 6973 and it’s a world of difference, at least in my Valco Harmony 430. It came to life with the RCA’s. Getting rare and I’ve only came across a couple of matched pairs that were within a 100$ or a bit more these last few years. Got burnt on one set but it has been worth it to upgrade to these old 50’s RCA. Don’t know how the Sylvania 6973 compare though? Finally have a great backup pair to boot. I imagine that many a modern Supro owner has tried them out but I have no idea of how they sound in that circuit that uses the EH’s.
I LOVE old utah speakers! They are spongy as hell and have a very unique tone. I have a quad reverb with utah speakers and they sound amazing with pedals. The quad utahs are the same speakers that kurt used on inutero. From what ive seen, a lot of blues and country guitarist hate these speakers compared to the jensen alternative.
That amp has the exact same tolex pattern, and grill cloth as my Airline 62-9017A. . Also has the exact same 35mfd 50v capacitors, which I'm getting ready to replace because one of them has exploded like a firecracker.
The amp sounds a bit boxy to me. Back in the sixties most of the guitarists I knew thought the Supros were crap. Their reputation has changed over the years. Entertaining and informative video, Brad.
Thanks for saving my Xmas, have you come across the modern Supro Black Magik? I like mine, has everything i need, trem, verb, 2 channels and master vol, seems very well built ( for a modern amp ), thank god Electro Harmonix still make the 6973 tubes though- I bought a couple of spare sets just in case anyway. Keep up the good work.
The pin out modification might have something to do with using a 6cz5 or even a 5cz5 if you used a resistor to reduce the heater to 4.7 vac on the 5 volt version, usually 1 ohm for two tubes.These are much much cheaper tubes and comparable tube data. Long plate 5cz5's are very cheap and plentiful, I have a huge stash of them :) Remember too that the way the 6973 and 6cz5 are rated differently on tube sheets and are very likely able to handle the same voltages. Try a 5cz5 long plate I think you will like. BTW I see you address the 6cz5 later :)
I still have my first real head an old peavey 70’s era super festival F-800G with matching 4S scorpion cabinet. Of course it’s not working so I’ll be reworking it. It has 10 final power amps, and I may switch it to tubes.
Since I'm an organ player and guitar player I'm a big fan of Jensen Special Design speakers for Fender, Wurlitzer, and Thomas Organ Co., but UTAH speakers sound great on the Fender Bassman 2-12" cabinets.
I could've swore I remember reading an interview decades ago with Jimmy Page, where he did claim to use a Supro amp in the studio for the 1st Zep album. He even stated that once he mentioned the Supro in a very early interview, how everyone began snatching them up, and he couldn't even find one to buy for himself. So what amp did he use back then? Hopefully, the answer is in this video, so I'll have to watch it again, because I can't recall.
Man, I have an old Bogen Challenger CH35 that I converted to a guitar amp a few years ago. It has 6973s in it and sounds very much like the Supro/Valco, I absolutely love the sound of those things!! Irun it into a 1x12 open back cab I built which I also put a Jensen 12" in. I actually have 2 spare pairs of 6973s I pulled out of an old Silvertone console stereo 😍 (yes, I saved the associated output transformers) Seriously one of my favorite tubes, just a big fat warm dirty sound.
Brad, what is that book you always refer too.? It seems to have everything you need in there. Really enjoy your videos too, if you have any vintage amps for sale I’d love to get one that you’ve worked on!
Hey, Brad, great in depth troubleshooting video!!! Your explanation on jumping the pins 1 and 8, should we jump those in an amp using 6973’s? It wouldn’t hurt them would it? Because I’m thinking of adding a switch instead of jumping directly, any thoughts? Thank you for all of your help in keeping this art alive! Wish I have a small fraction of your knowledge!!!
I can't prove it, but I do know Page said in an interview about 1969 that he used a small Rickenbacker amp in the studio for Zeppelin's first album. I had the privilege of getting one of the first copies of the album in early January of 1969 (or late December 1968). I remember he said Rickenbacker because I did a double take and thought to myself (being from America) that I didn't know Rickenbackers made amps.
Nice one! That amp sounds good. Also cool to hear some Orpheum history. I have an Orpheum archtop guitar that I've always figured was older than 1950s.
What a sweeeeeeeeet amp! 😎 6973's are probably my favorite sounding tubes. Haven't done a shootout comparing RCA vs EHX 6973's, yet, but I've read the EHX 6973's sound quite a bit darker than the RCA's, which is no big surprise there. Oh well, they're better than nothing I guess. I have a NOS matched set of RCA's sitting on my shelf that I paid about $100 bucks 2-3 years ago though.. Just waiting for a Supro to pop em in to! If I can't find an old one, I'd definitely like to pick up a Black Magic 1696RT. 🤘
@@TheGuitologist sounds about right to me! 👍 Thanks for confirming. It's a good thing you kept those vintage ones then.. You never know when you'll need them. 🍻
I like these and have two of them - one Gretsch and one National branded. I also built one with no tremolo from a Hammond organ chassis. Years ago I bought many 6973s and 6CZ5s. Per your comments about RCA tubes - they are built better and sound better than the Sylvania tubes of the same specs/numbers from the same time period. Their structure is quite different. Also, although tube manuals state different voltage ratings between the 6973s and the 6CZ5s the RCA tubes under a magnifying glass look absolutely identical except for the pin connections. So for the RCAs I think they are the same tube. And - do they sound like JP? Maybe, but I sure as Hell don't.
You must be a new viewer. Hand wired stuff is great,stuff with PCB'S suck and the modern amps with PCB are just garbage. Watch any of the Mesa videos that he has and you will find out
Those orange painted “Realistic” speakers were actually just rebranded made in the USA Utah speakers. They would have likely had an aluminum dust cap originally. Great speakers!
That was my first amp in the early 80s only mine was supro branded with the gray covering. Also the first amp that got sacrificed to the gods of learning amp building.
The Supro Model 5624 shows the 250/10 output bias resistor bypassed by a 35uF/50V cap which I didn't see in this amp. I bet that was the clipped off lead on the rectifier socket.
Great vid Brad, know your love for the old valcos I own a airline 62-9023a . Same thing! What are your thoughts about bridging channels on them notice the reissues has a switch for it?
it was rad that you had the correct speaker for this amp. it somehow reminded me of my cool old timer neighbor who had an pristine antique Winchester mod 94 lever action made in 1896 in 32-40 a caliber that was very hard to find in modern days, he told me that he had owned it for a long time but never got a chance to shoot it witch was on his bucket list. i told him to give me a few mins to go forage threw my strange ammo collection. i returned with 3 full 20ct boxes of cartridges the boxes wer for the 32win spsl witch he pointed out to witch i told him to check the head stamp on the actual cartridge and he let out a gasp...yup i said their all 32-40 sp nos. he asked what i wanted for them and my reply was for him to shoot them all then reload the shells a few times and just enjoy the experience!
Beautiful.
That's a. Wonderful story, you rock!
Awesome.
What you see on the scope at about 27:29 is classic crossover-distortion, suggesting that either the two output tubes aren't properly biased, or, they're worn-out, or, something isn't letting them operate correctly.
Valco nee 'Supro' made the kind of classic rock tone we came to appreciate on our 70s vinyl. These little amps sounded monstrous in the studio and truth be told, not too shabby in the garage or bedroom. Their early breakup and natural distortion from those, shall we say, inexpensive components Valco used are what made that tone!
always a great way to kick off the weekend with a new amp video from the Guitologist! thanks Brad, and have a great weekend!
Thanks for watching, Jon.
Brad and Uncle Doug on the same day... Perfect! Cheers!
Old amps like this have tons of character. This would be a great one to bring into the studio. Sure it sounds boxy in the video but mic'd up it would sound totally different.
Well, ya also have to consider the pesky compression that happens to audio when loaded onto youtube.
Sounds boxy because of the ceramic caps. Old and dried out. Orange drops would remedy that for pennies.
It's so relaxing to see you at work on all those old amplifiers. I only work on my guitars electrically like swapping out pickups now and then and experiment with different switching ideas. But I keep way clear of high voltage appliances. Keep up the excellent work, love your channels as well as your work 🙂
It's not HV! HV is like above 480 V I thought!?
This show just keeps getting better...the playing, that clip of JP showing the tele he got from JB
and that little 6970 supro with the 12' speaker., the phone call to SRVs amp tech. So much info
I may want to watch this one twice after I go check my national and my supro for the 550 code on the jensens
These are the kinds of videos that really make me wish I knew a bit more about electronics. Great stuff - the amp is really cool!
Hey Brad, greetings from Bulgaria! Your amazing videos are very interesting, educational and motivational! I want to thank you so much for it!
You are super professional musician and intelligent equipment technician! My respects!
Happy New Year 2023 to you, your family, friends, all the people around you and your followers here!
:-) God bless you all!
I have what I’m fairly certain is the Montgomery Ward equivalent (so to speak) of this amp and I have to say returning it to an old ‘66 C12Q was really what brought the whole thing home. As nice as the newer Jupiter speaker has the previous owner had installed was-the magnet was just to big or something.
Really enjoy your videos! It's great to see and hear these classics, many of which I wouldn't be able to get to see in person.
Thank you!!!
Dude I just love listening to you mess around playing the guitars ...the bonus is generally the old amps at that. Plus I learn a bit more about the good electronics each upload. Merry Xmas to you and fam Brad.
Everytime I watch your vids I get the itch to go out garage saling & hitting up resales shops!! Great job reviving that Orpheum, sounds decent even with the RS speaker! Thanks Brad!!
Hey Karl. Good to see you here. Thanks for watching, as always.
For my money, it sounded best with that ‘Dali’ Tele you were using at the end. Fantastic.
I remember having one of those orange realistics and liking it quite alot.
I think it would be perfect for some amps, just not this one. Too much dope on the cone for this one.
@@TheGuitologist would you mind explaining what you mean by dope? I don't know what this is referring to.
@@fredgarvin4482 It's an old school name for lacquer or any solvent based coating, clear to opaque. Lacquer, or dope, hardens when it dries, and would make the cone more stiff, effecting it's response.
Magnific! Love me some old Valco.
Other than the handle, the construction techniques and materials are identical to my old Airline 62-9017a. For any would-be Santas out there, I could use an Airline logo to make mine complete.
Great video - thanks, Brad!
Re-pop Airline logo's are available on Ebay. Black or White. They are glue on...no screws
@Timothy B . . I was thinking the same thing. I have the Airline 62-9017A as well. Man it's hard to find a whole lot of info on it. Mine needs work, and has probably been in someone's basement for decades. It does have the Airline logo, but it's missing the big V that goes on the front.
I recently took an interest in the old Bose Wave radios.
The prices are still high.
Apparently the capacitors need to be replaced, just like older guitar amplifiers
for whatever reason the algorythm has stopped telling me when you post new videos... thankfully i check in once in a while to those i follow and appreciate. Merry Xmas Brad! keep making the great content you make ! love from Canada
Nice work and playing Brad, thank you Sir! Have a good weekend! :)
I'm gonna comment before even watching today all because of your thumbnail for this vid. RED ZEPPLIN roflmfao! Very clever bro and Merry F'n Christmas! lol
My 1967 Supro Thunderbolt was a Valco Amp and it came with 15" Jensen speaker
Wow looking at the square nuts on the side of the amp. Cool. That’s what voice rub sounds like. 🙏 thanks.
man i just love your intros
Found one about 15 years ago at a salvage store $50. Got new can cap new rec tube and a new after market handle and a grounded power supply. Ended up at around $450. traded it to a guy that swore it was a page amp. The guy that repaired it said Jimmy didint play or record with this amp.I told him. I made out like a bandit.
Beautiful vintage tone that blows anything current out of the water...
Hey Brad, As you obviously know, Valco made the same amp branded for several companies. My second amp ever was the Supro version. A few years after I had moved on to other amps, I read an interview with Page that had photos of the same amp but with a Gretch badge. Jimmy referred to it as having two 10" speakers. My little Supro also had two 10s and although his amp looked darker in the black and white picture, and had the different logo, they looked identical. Just my 2 cents to muddy the waters as to the brand of Jimmy's amp. Thanks again for all the great 'edu-tainment' you provide!
Good timing - I just bought the same amp --- but it's the VALCO AIRLINE version 62-9033A Appears identical. Mine appears all original. Has the original tubes - all RCA's including the 6973's. Original Jensen C12Q. Killer tremolo! Great to see your video to help me go thru the amp! QUESTION --- I'm thinking this is the same circuit as the VALCO Gretsch 6162, except the addition of reverb on the 6162? Thank you!
I've had a couple of these over the years... they really have maximum bark!! Some amps break up so gradually... but these really jump at you... I would have liked to hear it miked up well, to show what they do with a good mic or two catching that speaker and amp drive
I have no idea what this is all about, but i realy like watching it. I think it's an engineering mentality thing. Keep posting! Love this content.
The demo playing is always killer to watch. Nice old amp Steve has there and sounds good too.
Great playing once again man!
Steve Wilson worked on my 65 Gibson Mercury amp last year,an old barn find,glad to bring this old amp back to life.Tell Catfish hi for me next time you see him for me Brad!😁
🤗🤗 That amp sounds really great!! Old pro tip, ....record with a small amp to get a huge sound.....good advice. Thanks Brad..Cheers and Merry Christmas!!
More like a dumb tip...smh
Considering that's what a lot of old pros did, it's more like a fact. 😎
@@enigma1247 The engineer that mixed Def Leppards Hysteria album (plus others) showed me how their producer, Mutt Lange, got such huge guitar tracks. He opened the door to the vocal booth and sitting on a stool was a small guitar combo amp with a 10" speaker. it had great sounding distortion and drive and it was conversation loud. Stack a double handful of tracks with different tones: Voila!
The rubbing speaker coils: If the coils are not detaching from the cone, remove the dust cap, shim out the coil, inject a small amount of water and let it evaporate for a couple of days. No guarantees but it might work and save a recone job. Good luck.
Yep it works, I used acetone though.
I've seen that V/I = Futile sticker countless times, but it wasn't until this moment that 'Resistance is futile' jumped out at me.
Good call on the 5y3…the higher voltage from the 5ar4 + the higher line voltage today vs 1960s, a lot of components would have been cooking in there!
Excellent work per usual, Brad!
Hey Brad. IDK, it could be me, but at about 36:40- 36:41, when you are putting the nut on the screw, I noticed rocking, of something. I don't know, if it was the spkr. rocking on a potentially slightly warped front panel, or if it was the entire amp, rocking on the bench. Wouldn't the first scenario, also warp the spkr. ring, when tightened, creating the cone rub?.. Like i said, it might be me, but there was a definite rocking motion, somewhere. And, if Steve replaces the spkr., it may cause the same issue, with the new spkr..
Brad, I'm a long time sub with ALL notofications turned on for your channels. I have not been notified of any of your recent videos. Just a heads up mate, hope you are all doing well and best wishes from Canada!
I know. You and I both know why.
@@TheGuitologist yea, usually they just effect non sub interaction... seems they are going to a new level lately... it sucks as it effects people's ability to learn from your videos as well :(, keep up the good fight man, we're rooting for ya!
Same here!!!!
Jimmy through his original rig hits hard!
Telecasters rule!
Wow- Thanks Brad! That amp is RAGING!!
A very nice video! Thank you Brad and Steve!
Nice! I was hoping you would do a video on one of these type amps!
Man oh man mega respect dude. Wish I could work on or build amps😁👍
Just scored two military RCA tubes from 1944.
A VT-115 A 6L6G and a VT-115 CRC6L6.
I have A/B’d the EH 6973 and RCA black plate 6973 and it’s a world of difference, at least in my Valco Harmony 430. It came to life with the RCA’s. Getting rare and I’ve only came across a couple of matched pairs that were within a 100$ or a bit more these last few years. Got burnt on one set but it has been worth it to upgrade to these old 50’s RCA. Don’t know how the Sylvania 6973 compare though? Finally have a great backup pair to boot. I imagine that many a modern Supro owner has tried them out but I have no idea of how they sound in that circuit that uses the EH’s.
I agree with pretty much everything you just said.
That PT is super clean. Looks brand new.
I keep missing these premieres dude. TH-cam never notifies me for your videos anymore.
Love watching these, learning every day
Love your vids mate, they're always awesome and this one rocks too ! Keep up the good work.
Glad to see you are back informing us of obscure stuff...stay strong and THANK YOU! this is my Christmas present Sir Bradford😊😏😏
Love the old Valco. Pull the speaker from an old Hammond. Alnico , 16 ohms @ 15 watts. Perfect voicing
True! It's fairly easy to pick up old Jensen's online (reverb, eBay), for not much money too. I have one from an organ pull and it sounds great.
I always enjoy your gear related content 👍
Woo Hoo like number 235! Great video man. Keep up All of your good works, here and in the real world. I believe in you.
You're too kind. Thanks Cecil.
Great video, Brad! Keep it up!
I LOVE old utah speakers! They are spongy as hell and have a very unique tone. I have a quad reverb with utah speakers and they sound amazing with pedals. The quad utahs are the same speakers that kurt used on inutero. From what ive seen, a lot of blues and country guitarist hate these speakers compared to the jensen alternative.
Would have loved to hear it close miked
RCA projectors, like the one you showed a few years ago, use 6973 output in push-pull configuration. I still have a nice amp pull from one.
Voiced like Jimmy and his Tele' I believe that Zio found its mate!
That blows away my boss tremolo pedal.
Excellent video, Brad. Thanks
That amp has the exact same tolex pattern, and grill cloth as my Airline 62-9017A. . Also has the exact same 35mfd 50v capacitors, which I'm getting ready to replace because one of them has exploded like a firecracker.
The amp sounds a bit boxy to me. Back in the sixties most of the guitarists I knew thought the Supros were crap. Their reputation has changed over the years. Entertaining and informative video, Brad.
They were made for accordions and mics. An Italian tradition.
Thanks for the video. You make tube amp repair look like commen sense. Keep on rocking
Thanks for saving my Xmas, have you come across the modern Supro Black Magik? I like mine, has everything i need, trem, verb, 2 channels and master vol, seems very well built ( for a modern amp ), thank god Electro Harmonix still make the 6973 tubes though- I bought a couple of spare sets just in case anyway. Keep up the good work.
Looks like those marketed by Gretsch too. Another informative video. Thanks!
The pin out modification might have something to do with using a 6cz5 or even a 5cz5 if you used a resistor to reduce the heater to 4.7 vac on the 5 volt version, usually 1 ohm for two tubes.These are much much cheaper tubes and comparable tube data. Long plate 5cz5's are very cheap and plentiful, I have a huge stash of them :) Remember too that the way the 6973 and 6cz5 are rated differently on tube sheets and are very likely able to handle the same voltages. Try a 5cz5 long plate I think you will like. BTW I see you address the 6cz5 later :)
I still have my first real head an old peavey 70’s era super festival F-800G with matching 4S scorpion cabinet. Of course it’s not working so I’ll be reworking it. It has 10 final power amps, and I may switch it to tubes.
Could make for an interesting video.
The realistic speaker sounds great
Since I'm an organ player and guitar player I'm a big fan of Jensen Special Design speakers for Fender, Wurlitzer, and Thomas Organ Co., but UTAH speakers sound great on the Fender Bassman 2-12" cabinets.
I could've swore I remember reading an interview decades ago with Jimmy Page, where he did claim to use a Supro amp in the studio for the 1st Zep album. He even stated that once he mentioned the Supro in a very early interview, how everyone began snatching them up, and he couldn't even find one to buy for himself. So what amp did he use back then? Hopefully, the answer is in this video, so I'll have to watch it again, because I can't recall.
These sound so awesome. But why do we hear that Jimmy used marshalls?
Man, I have an old Bogen Challenger CH35 that I converted to a guitar amp a few years ago. It has 6973s in it and sounds very much like the Supro/Valco, I absolutely love the sound of those things!! Irun it into a 1x12 open back cab I built which I also put a Jensen 12" in. I actually have 2 spare pairs of 6973s I pulled out of an old Silvertone console stereo 😍 (yes, I saved the associated output transformers)
Seriously one of my favorite tubes, just a big fat warm dirty sound.
Great offering ! Bummer about the speaker.
I miss Radio Shack.
I am digging the overdrive tone on this amp. I bet it would even better with a more closed back
Damn, that sounds good. I really want one of the old Supro amps. Maybe one days I'll find one.
My Jukebox has 6973.... I THINK....... damn, gotta check my old videos. I put the EH in there, and it's been a non-issue.
daaaym i did not see that coming.. how well it sounded
No filter cap change?😮
Brad, what is that book you always refer too.? It seems to have everything you need in there. Really enjoy your videos too, if you have any vintage amps for sale I’d love to get one that you’ve worked on!
Hey, Brad, great in depth troubleshooting video!!! Your explanation on jumping the pins 1 and 8, should we jump those in an amp using 6973’s? It wouldn’t hurt them would it? Because I’m thinking of adding a switch instead of jumping directly, any thoughts? Thank you for all of your help in keeping this art alive! Wish I have a small fraction of your knowledge!!!
These are the same (Utah) speakers as my 71 twin reverb,I'm not the original owner but I believe they were stock, sound good.
I can't prove it, but I do know Page said in an interview about 1969 that he used a small Rickenbacker amp in the studio for Zeppelin's first album. I had the privilege of getting one of the first copies of the album in early January of 1969 (or late December 1968). I remember he said Rickenbacker because I did a double take and thought to myself (being from America) that I didn't know Rickenbackers made amps.
Maybe it was made by Supro for Rickenbacker
31:43 Are you Longmont Potion Castle's amp tech? lol
Nice one! That amp sounds good. Also cool to hear some Orpheum history. I have an Orpheum archtop guitar that I've always figured was older than 1950s.
That wuz great, Brad...
Thankum wally mooch
What a sweeeeeeeeet amp! 😎
6973's are probably my favorite sounding tubes. Haven't done a shootout comparing RCA vs EHX 6973's, yet, but I've read the EHX 6973's sound quite a bit darker than the RCA's, which is no big surprise there. Oh well, they're better than nothing I guess.
I have a NOS matched set of RCA's sitting on my shelf that I paid about $100 bucks 2-3 years ago though.. Just waiting for a Supro to pop em in to! If I can't find an old one, I'd definitely like to pick up a Black Magic 1696RT. 🤘
darker and lower volume. Lacking in some top end sparkle. I think the output is less with EHX.
@@TheGuitologist sounds about right to me! 👍 Thanks for confirming. It's a good thing you kept those vintage ones then.. You never know when you'll need them. 🍻
I like these and have two of them - one Gretsch and one National branded. I also built one with no tremolo from a Hammond organ chassis. Years ago I bought many 6973s and 6CZ5s. Per your comments about RCA tubes - they are built better and sound better than the Sylvania tubes of the same specs/numbers from the same time period. Their structure is quite different. Also, although tube manuals state different voltage ratings between the 6973s and the 6CZ5s the RCA tubes under a magnifying glass look absolutely identical except for the pin connections. So for the RCAs I think they are the same tube. And - do they sound like JP? Maybe, but I sure as Hell don't.
Also, Brad, do you have any video on your take on modern circuit vs hand wired amps? I’d love some input from you!
You must be a new viewer. Hand wired stuff is great,stuff with PCB'S suck and the modern amps with PCB are just garbage. Watch any of the Mesa videos that he has and you will find out
Those orange painted “Realistic” speakers were actually just rebranded made in the USA Utah speakers. They would have likely had an aluminum dust cap originally. Great speakers!
That was my first amp in the early 80s only mine was supro branded with the gray covering. Also the first amp that got sacrificed to the gods of learning amp building.
The Supro Model 5624 shows the 250/10 output bias resistor bypassed by a 35uF/50V cap which I didn't see in this amp. I bet that was the clipped off lead on the rectifier socket.
It's there. It's going from the other tube cathode to ground. The cathodes are connected together with a wire.
That yellow & black 35/50 capacitor jumped out at me immediately. My Airline amp has several of those.
Just to clarify-18:30-the word is pronounced `Trem-olo! Not Tre-molo! Otherwise-great and interesting work
My first show was at the Orpheum in Boston in 77... The Dead.
Great vid Brad, know your love for the old valcos I own a airline 62-9023a . Same thing!
What are your thoughts about bridging channels on them notice the reissues has a switch for it?
I don't think the reissues are anything like the originals. You can jumper channels on this though. I just didn't do it for the demo. Slipped my mind.
I find these videos so interesting.
Is there a schematic for this amp because i’d love to build one of these!
dude great sound great fix and sweet prs
Thanks for listening
My Uncle sold them in his Detroit music store for acordion in 1958.
What a beaut! Nice growl on that thing.