Secrets of the Fender "Twin-Amp" - Uncovering & Restoring a LOST CIRCUIT!

In this video, we'll use all our amp archaeology skills to uncover the original LOST CIRCUIT of the early, 1953 tweed Fender "Twin-Amp". The Twin Amp was Leo Fender's first 212 combo, and the first time he'd used separate Bass and Treble controls in a guitar amplifier. It also harbors a secret. The first iteration of these amps had a different tube compliment than the earliest published 5C8 schematic. The 5C8 schematic has a 6J5 tube before the tone stack, while the earlier amps - the first couple hundred perhaps - had all 6SC7 tubes. Without a schematic to go from, we'll have to examine the evidence closely and try to figure out what the original circuit was after decades of services and mods.
----------------------------------------
Check out the SONG | Songwriting Inspiration app:
magicalpick.ap...
----------------
GUITOLOGIST MERCH: teespring.com/...
SUBSCRIBE TO CHANNEL 2: bit.ly/Guitolog...
----------------------------------------------------------
SHOW YOUR SUPPORT
1: Donate via Paypal: paypal.me/guit...
2: Buy Merch: teespring.com/...
3: Send in Viewer Mail. (Contact Me for details at [e-mail] )
4: Purchase an ad! (Rate sheets available upon request at email above.)
5: Buy something from a sponsor and tell them I sent you.
6: Stand in the middle of the street naked screaming "LONG LIVE THE GUITOLOGIST!" Then when the cops arrive, tell them about my channel.
------------------------------------------------------------
♠STUFF I USE
-5A Variac: amzn.to/2FNWthU
-Jameco Isolation Transformer: amzn.to/2PRv1Fa
-Fluke 87: amzn.to/2DwHjvr
-Yotec 936 Soldering Station: bit.ly/2JqB1Vw
-Sealody SSA51 soldering station: amzn.to/2DJTS7P
-Black and Decker Heat Gun: amzn.to/2DWpDhr
-Geekcreit® LCR-T4 Mega328 Transistor Tester bit.ly/2J9uLSA
-HT02 Handheld Infrared Thermal Camera bit.ly/2LXfLoD
-Solderless Breadboard: bit.ly/2stkVAq
-Breadboard Jumper Wires: bit.ly/2JowaEh
-Geekcreit® XR2206 Function Signal Generator DIY Kit bit.ly/2LYBvkb
-Contact Cleaner: amzn.to/2FVitro
-Max Professional Cleaner and Lubricant: amzn.to/37R3JY8
-Deoxit Fader Cleaner: amzn.to/2LPwtsE
♠RECORDING
-JVC Everio Camcorder amzn.to/2RLIleU
-Andonstar USB Microscope: bit.ly/2q8QIWz
-Articulated Boom Arm with Cam Mount: amzn.to/2Hlo2AX
-Shure Beta 87A amzn.to/2rNPnoW
-EV 635A Omnidirectional Dynamic Mic amzn.to/2pR8HQT
♠RECOMMENDED BOOKS
-RCA TUBE MANUAL amzn.to/2GOBVqS
-DESIGN AND CONSTRUCTION OF TUBE AMPLIFIERS: amzn.to/2HSNMne
-Designing Tube Preamps for Guitar and Bass: amzn.to/2DK5tmt
♠2006 FENDER AMERICAN STD TELECASTER PICKUPS
-TV Jones Magnatron Neck: amzn.to/2q1zQjD
-Seymour Duncan Vintage Stacked Bridge: amzn.to/2GyZjrK

[@jenniferwhitewolf3784]

Steel guitarist and electronic guru Freddy Tavaris dropped in to Fender one day to complain about problems with Leo's amp designs. Leo hired him on the spot and he remained his technical right hand man, staying with the company long after the CBS sale. Many amp improvements were made co-incident with Tavaras joining the company. It may be possible that the changes seen in this amp early in its production were done by him. I'll need to check my books to confirm the dates, but its in this general time period. Also, everyone blindly gives credit to Leo for everything related to the company... which is not the way it was. His business manager Forrest was also a brilliant production engineer and totally changed the factory floor layout and materials handling.. as Leo had a freaking mess of a shop with no inventory control. Much of the product design came from George Fullerton and Freddy Tavaris. Leo hired a few great people in key positions that had a major impact on the positive evolution of the company. Sadly, when he sold to CBS, non of the key people were included in any way in the massive profit that Leo took. Forrest in particular had been offered a share of ownership that was never, NEVER, followed through by Leo.

[@whimpypatrol5503]

I always suspected Leo Fender could not have pulled it off without unfamed gurus of his day.

[@MrGavinspoppop]

didn t know

[@roadshowautosports]

As it is today, in history we always find very successful and famous people that promised a lot to the real geniuses but never delivered. Have you heard of a “genius“ called Steve Jobs? I bet you did! you’ve heard a lot about him, read the books, watched the movies, listened to the soundtracks, BUT very little was said about the other Steve! Yes! The other one! What is his last name? Oh yes, Wozniak! The one who actually MADE the computers and took a lot of Shit from the so called“genius” during the process. This is typical of many situations where a name is mentioned while it’s not the one actually doing it. Not saying Leo wasn’t capable of (much better than Jobs), but it would be very noble to mention all the people responsible for the great products and give them what was promised. Very sad to hear that. He was one of my idols from that era and considered him an innovator but never knew he could be that way.

[@jenniferwhitewolf3784]

AnticommentWarrior He was tired, and wanted to enjoy some play time.. He took millions, bought a yacht and went boating... He did try at some point to make it up to both Forrest White and George Fullerton by starting small companies with them... The venture with Forrest lasted only a short time, but the other stood the test of time, that being G & L.., George and Leo. G&L still survives as a company, and still has much of the original shop equipment that was once at Fender, all sold when CBS built huge new production facilities. There are youtubes of tours through G&H talking about all the surviving Fender benches, cabinets, and even drawings.

[@harrypalmer3481]

@@roadshowautosports Thomas Edison has to be the ultimate example of this. How many of 'his inventions' were actually invented by him? The more you delve into it, with reliable citations/evidence, the darker it gets, really quite depressing. Arguably his success could be attributed, along with undoubted intellect, more to Machiavellian psychopathy than to genuine genius like Nikola Tesla. For clarity - I don't place Leo Fender in this level of category! As it appears to me, Leo Fender was great &, like most people, part good & part a bit of a sh¡t.

[@dyamariv3628]

Brad is BACK!!!! Nice to see you working on amps and sounding more like yourself again :) I watched every second of the video, loved it all especially the added history part at the start!

[@TheGuitologist]

Thanks. I appreciate you watching.

[@jenniferwhitewolf3784]

Glad to see him back in 'in the realm' as well..

[@fuzzcityrecords432]

Dude you are crushing it on the custom intro game

[@TheGuitologist]

I have some very cool channel fans who made some of those for me. I made a couple on my own too, but theirs are better. :D

[@orenalbertmeisel3127]

Great to see you’re doing a guitar amp centered video again! Btw I’m not here only for the amp content, I do in fact enjoy the majority of your content.

[@TJHill-fk1cp]

Same here 👍

[@JazzStrat781]

@@TJHill-fk1cp Same with me

[@jerrystephenson1172]

ditto

[@TheGuitologist]

Thanks for watching the vids. I appreciate it.

[@Cpt_Adama]

I agree, that was the whole reason I came to this channel in the first place. His channel kinda fell off my radar lately so I hope he continues to bring more of this content.

[@roadshowautosports]

Hey, Brad, thank you for all of your videos. I confess that on the time I’ve first saw your videos i sincerely thought you were an amateur trying it ou things on electronics! I guess by your simple way of talking I couldn’t see the master of this craft that you really are! I’m amazed by the way you can troubleshoot every defect by just simple hints in the circuit! You always start with s simple “I bet...” and your intuition is pretty much on the spot! Sometimes, like in this video, by mentioning possible causes for the humming, you made it look so simple and intuitive while taking away the fear we all have of amplifiers. I didn’t even know one could remove tubes while the amp was ON!!! From there you show such a professionalism and care for the subject as well for its owner when trying to keep it original but functional. Another great quality of yours is how humble you are by not editing so much out of the final product to show how you finally find out what is causing it, your own “mistakes”, and how you got to the solution! You’re a blessing! Thank you!

[@alexkatsaros6180]

Hi Brad, I am a technical officer of 40 years experience. You have noted in other videos that some people have commented on the things you show or not show. I for one appreciate the the need for keeping videos short and or condensed. For me I completely understand and support what you do. I find it informative and entertaining. Please keep up the good work! Alex

[@TheGuitologist]

This presentation is over 1 hour and I showed less than half of the repair process. So you get it, I think.

[@DetroitWrecker666]

I love how you don't bullshit us. You show the issues you run into even after you have completely serviced it. Thanks for being YOU, Brad!

[@hrsey71]

I liked the info in the beginning! you should do that more often

[@Tomater768]

Now that's an amp! Love the old tube amps of the 50's. Getting rarer than hen's teeth to find! Thanks for sharing this one with us! There's a reason why those are Clapton's favorite!

[@krzysztofstokosa9786]

Man I love watching those 1h+ vids while working on a guitar. Lots of stuff I learn just by listening in sometimes taking a break from guitar and watching the content up close. Very interesting insight on the history and schematics, cant appreciate enough what I learned on your channel.

[@lpjbird]

Wow, not knowing squat about electronics, this was like all Chinese to me, but this video captivated me from start to finish with the patience & persistence you took tracking down the noise issue. That’s what separates the men from the boys in my opinion. As many times that must have been in for maintenance and buttoned back up without anyone noticing the grounds at the input jacks along with everything else. Amazing, I’m totally blown away, & them some sweet sounding chops to boot. Made my day, thanks.

[@USMarine75]

Agree with others... this was a great "new" format IMO for your vids with the informational -> repair -> demo.

[@thomasturner8474]

I was super happy to finally see an amp video again. Then I was even happier about the new format and production quality... then I saw Brad wearing a Tool shirt. All is right in the universe. Glad you're back, Brad.

[@gobigrey9352]

Dead quiet until you blow the windows out with an E chord.

[@gregg3525]

Welcome back Brad! This world needs you brother:)

[@lancehall3897]

Fantastic craftsmsnship in this amp and appreciated the deep dive you did in setting up the circuit

[@TheGuitologist]

Thanks Lance. Glad you dug it.

[@scottfulghum4398]

In 2003 I was in the shop picking my 68 twin and a fella walked in with his 52 twin. He was the original owner wanting to get it checked out before selling it. This gentleman was in his 80’s and used this amp all throughout his career as a steel player. I played it. It sounded like a toy compared to the high power twins. It broke up early but not as early as the 52 Deluxe I had the good fortune to play through. They both had similar tones. The twin was just a completely different animal compared to what I was used to. He was trying to get 6000 for it at the time. I wonder if he ever got the money he wanted? I enjoyed more so just meeting this man and having the connection with history.

[@patreidcocolditzcastle632]

how can you not love brad,this was great it made me open up my best amp a 1972 guyatone reverb jazz,basically a fender super reverb.and i noticed my tech did what brad did put in great caps and good pots.i love old amps they just do all you need

[@martinreid1740]

Back to what you do best Brad. A thourghly watchable and educational video, well done.

[@TheGuitologist]

Thanks for watching, Martin.

[@amphetamineblue4172]

Great to see another in depth vintage amp repair vid. Keep them up Brad !

[@joshuaweiner6378]

Great to see a classic Brad amp video again!

[@stevemartin9035]

I wonder if the tech before had stuck the 6SN7 in the mix position of the tone stack with the 50uf bypass cap. The lower mu tube may have allowed the preamp to load more into the tone stack. Interesting to have tried that with the tube complement originally supplied. Lot of work involved there, and time and money. Working on these older is always a challenge considering that Fender prototyped on the fly during this time. He'd loan an amp out, and someone would bring it back with comment, and they'd make a change. Jim Marshall was the same in developing his amps. Artist input was what drove the innovations.

[@TheGuitologist]

The 6SN7 is a different pinout than the 6SC7, so I don't think they were using it in the tone stack driver position. But yes, the supplied tubes does leave a bit of a mystery... The owner did say when he dropped the amp off that one channel seemed to not be working at all, so I assume that's because there was a 6SC7 in a socket re-wired for a 6SN7. I'm sure the amp would be more flexible with a different tube in the V1 or V2 position so that channel would respond differently, but in this case, I think re-wiring to factory spec was the right move because of the historical interest of the amp.

[@jayguitar]

Great to see you working on amps again Brad! I have missed these videos! 😊🤟🏽 have an amazing day dude!

[@boomeri]

This video made me want to 1. Get myself a Fender amp (never owned one ever) 2. Get back to working on my myriad of unfinished amp and guitar projects 3. Get a Bigsby for my Tele Stellar video, these are the kinds of videos that made me subscribe years ago. I often watch these while doing fretwork on guitars etc. Keep 'em coming, and thank you for the awesome content!

[@toddweaversound]

I was working on a tweed bassman today. It had the same noise and microphonic issues. I thought about emailing you for a solution, but then I decided to man up. Perhaps subconsciously remembering what caused the noise issue with the non grounded input jacks from this video made the fix quick and easy. It wasn't acting like an asshole because of all of the ways it could, it was behaving exactly as it should with ungrounded multiple inputs.

[@PaulNickens-nu9xp]

Hey Brad!!!! I really enjoy your channel, tech chops, and musician chops. According to Aspen Pittman and certain associates of Leo Fender, Leo resisted attempts from his design engineers to stabilize the output of his amplifiers making them more linear and audiophile. Leo knew that his claim to fame was that when his amps were pushed to clipping by musicians of the day they cipped musically and this is what sold Fender amps. The first thing that Leo's design engineers did after the CBS acquisition and Leo's departure was to design Ultra Linear amps to stabilize the output of Fender amps like the silver face Ultra Linear Twin 135 Watt Amp. Leo hated this. Leo loved the fact that his amps clipped musically and was averse to the new 'audiophile' direction that his engineers pursued. JAFWIW

[@donwilliams9661]

Nice tribute to Eddy too... and great to see you working on tubes again..

[@bdubbstsi]

Dude love the history section. You do a great job with it.

[@TheGuitologist]

Glad you dug it. I'll try to do more in the future like this.

[@akc5150]

Beautiful homage to EVH with 1984 in there. Cool vid and never realised the old Fender twin could get such a gritty sound!! Possibly why Eddie himself used Fender amps back stage in the warm up room!!

[@TheGuitologist]

I'd forgotten about Eddie using Fenders for that. I think I read that in an old Guitar World interview back in the day?

[@joeyboogenz]

My God ,Dude. You are an engineering marvel. I have been sending your vids to my Son ,who is an Engineering major in college. Thank you for all you do !

[@NitroModelsAndComics]

Good to see you back on amps brother. I'm hoping 2021 will see us ALL better and shaking off what can only be described as the bastard of years, 2020. Here for ya any time bro.

[@jasonkeen712]

I wish I had a tenth of the knowledge you have. Great video. I've been watching for a few years and I'm glad you're back doing your thing.

[@multishit6664]

''How to play every mode ALL AT ONCE and confuse the hell outta people" that was FUKIN hillarious

[@TheGuitologist]

I thought someone might get a kick outta that. :D

[@nellayema2455]

Good work! The amp sounds great. I can imagine an old-timer blues player kicking back on his porch playing through that amp.

[@woodyTM]

Another phenomenal video Brad! Thank you for taking the time and effort to produce such quality content, never has it ever not been enjoyable to watch these with my full undivided attention. This definitely takes priority over watching an hour long episode of whatever the heck TV shows you'd find on a streaming service.

[@TheGuitologist]

That is a glowing compliment, Jonah. I appreciate you saying so.

[@keithrevst692]

Brad you knocked this one out of the park. You are back and better than ever. I hope you continue putting out great content like this. We are pulling for you. Good luck.

[@florisbackx1744]

Brad back to fixing old amps, life is good : )

[@DerekHerbst747]

I dig the vibe you hit in this video. Nice to see you have your Mojo back! What a great old amp!

[@michaelmenkevich5712]

Great tutorial on vintage amp repair and troubleshooting, and amazing focus and determination. You stayed with it until you got it right. Brad is back! and nice tip o the hat to EVH. Thanks

[@TheGuitologist]

I think like a lot of other people, I've been reconnecting with Van Halen music since his death, and we really lost a luminary of massive importance. That much is clear.

[@emilychristoff9404]

Sweet sounding now i see why die hard electric guitar players love and want these old fender tweed amps. Learned something new today about circuits etc. I do love Hi Fi tube amps it warms up cds and gives life to vinyl! Thank you for posting!

[@graxjpg]

This is like a damn tv show it’s so well produced. Except there is no slime coming out of my TV set!

[@tsloth1390]

Excellent video, Brad. I’m glad you’re in a place where you can get top notch videos like this out to us! Great job dude, love it. 2020 has been such a bummer, I know you’re feeling it too and I just want you to know, whatever ideological differences we have, I really, really appreciate your knowledge on the subject of guitar electronics, which has turned out to be one of the most fulfilling parts of my life, thanks, in significant part to you and Uncle Doug for making it feel possible and straightforward. Keep it rockin’ man!

[@williambock1821]

Tommy Miner Right there with ya!

[@michaelmattson3515]

Like the album under the lamp.

[@johndodson4527]

I need a transistor for an old alamo amp.can u help me?

[@johndodson4527]

Itt 5210

[@Eddy63]

Jeremy Brett ... One of my favorite Sherlock Holmes ... Good vid ''The Old Brad '' ... Welcome back ...

[@TheGuitologist]

He WAS Holmes. He died playing that part. Pour his soul into it.

[@marknash7113]

This is one of the best amp projects that you have posted. The history and design era specific sleuthing to resolve the noise issues was so informative. It resolved questions Iv'e had with grounding design at Fender for years. Jennifer's comment is excellent historical input on who influenced the technical show at Fender. More please sir?

[@grateful4068]

Brad, you're the man! MVP. Videos like this are "the heart," as they say.

[@TheGuitologist]

Thanks for watching.

[@BMichel347]

That amp with humbuckers whooooo!!!!!! Excellent

[@thorc7762]

Great, informative video Brad.. I enjoyed nerding out on this twin..

[@WarrenBey]

He's BACK!

[@gunsofsteele]

"Check out the big brain on Brad! Jules Winnfield Nice repair! Great amp!!! ✌️

[@guitmickify]

That's awesome, and a cool coincidence. I recently scored a '57 Twin reissue on Reverb that had some heavy abuse, I've repaired the cabinet and just dropped it off yesterday to amp repair guy. I'm pretty excited to have one again, just a couple years ago I sold a '61 that I grew up with, and I was kind'a missing, even though it was such a beast :0)

[@timka880057]

Thanks Brad! This vid was truly entertaining. I was with you the whole time. I was glad when you decided to redo the heater wires and put a virtual tap to ground. I've had to replace jacks on a amp, which had no extra ground lugs. I wish I could show you a picture of the different style jacks I put in. The nuts are wide stainless steel, looks crome plated; decorative. I can't remember the name or where I got the first ones. I think they were given to me to try out. Bit it did make the amp look better and no noise.

[@TheGuitologist]

Cool. I'd like to see those sometime.

[@lloyddomke9563]

That is enough high end to make Johnny "Guitar" Watson ask for the treble to be turned down.

[@ericmdk]

On the single coils I felt it could get wild on the high end, humbuckers it seemed fine. I wondered about a better speaker to pair with it, but I've never messed with alnicos. Maybe just turning the treble knob down to suit your tastes would do the trick.

[@TheGuitologist]

heheh...yeah, I might have overdone it with the treble in the Tele parts. The camera mic was set to "Auto Level" on those parts too, which didn't help. I did the PRS parts with manual setting a bit lower. The thing is though, with a tone like that, it's going to CUT through a mix. Listen to old Stones records. If you isolated the lead parts, they would be this trebly, but in a mix, they sit where they're supposed to. If you make your lead tone too "creamy", you get lost in a mix and frankly, I think you lose the edge that a lead tone should have. A lot of shredders get this wrong, IMO.

[@WS-ij1fu]

I've seen many youtube videos about underrated guitarists/forgotten guitarists and Johnny "Guitar" Watson is never mentioned he was a superb guitarist and more unusually he was a superb musician.

[@RHR-221b]

@@TheGuitologist 😎 Agreed, B. R

[@buckodonnghaile4309]

@@WS-ij1fu Frank Zappa mentioned him as an early influence of his and played with him later on. That's how I discovered him

[@dmueller78]

Great format on this video. I really like the fast-paced history segment with the background music. Great job putting this together, Brad. Thank you!

[@RJ-bn5uw]

Lol , Jeremy Brett ! He rocked as Sherlock Holmes .

[@TheGuitologist]

He was the best Holmes. The man played that part to perfection. He died playing Holmes. Gave it everything he had.

[@willmorrison1022]

@@TheGuitologist Absolutely. He wrote 7 or 8 notebooks on observations on who Holmes was and how he thought. The man took the character seriously, and it shows in his portrayal. Rathbone was good, but Brett is the master.

[@dogpaw775]

i'm starved of live music, this dude jammin' is food for the soul.

[@TheGuitologist]

We are ALL starved for live music. Can't wait until we all cut the shit and get back to life. I'm done.

[@Bo-Yan]

Dear Brad, thank you very much for your interesting and helpful videos! Be blessed, healthy and happy, and I wish the same for all the people around you, and all your KZbin audience! Greetings from Bulgaria! :-)

[@TheGuitologist]

Thanks. I appreciate the support.

[@Bo-Yan]

@@TheGuitologist You are welcome!

[@russellhltn1396]

Why do I get the feeling that Rick Beato is living rent-free in your head? ;)

[@TheGuitologist]

Can't evict because of covid.

[@lordhydromage6614]

@@TheGuitologist hahahahahahahahahahahah

[@lordhydromage6614]

Russell. In his defense we at Song sent him down that path for our new ad. Not directly but with a long conversation of how to reach the group of folks that would benefit most from using our app.

[@hgostos]

Love those SoZo Blue caps... great in Fender style amps.

[@TheGuitologist]

This was my second experience with them in an old Fender. I think they offer a high-end feel to the project. Anyone who opens the back to inspect it should be impressed with the component selection. I think it just shows someone competent cared about it.

[@thorerik678]

Great job of sleuthing those troubles away! Even though I have been in the electronics game for many moons I continue to learn new stuff from you. Keep it up.

[@TheGuitologist]

Thanks for the comment. Glad you got something out of it.

[@bobbarcus8310]

Good Job looks cleaner Glad you got rid of the OD and IC caps fixed the ground wires

[@roncarter2188]

Did they do a reissue of this amp, that amp is a beast! I like the 6sc7 preamp tubes in the V1 and V2 positions. To bad there isn't a schematic for this amp.

[@Mojoman57]

A Fender amp repair that would even make Uncle Doug jealous! Great video and amp.

[@TheGuitologist]

I like to think Doug and Jack and the rest of his menagerie would approve.

[@Mojoman57]

@@TheGuitologist Oh, man. He's a Fender circuit fanboy for sure. I bet he's droolin' over this one. Or slobbering possibly.

[@johnsmith-bk4ps]

Uncle Doug shotguns everything. He should stick to tv sets

[@dlunsford1980]

Having built an all octal amp in the past, they can be challenging preamp tubes to work with. Much of the used old stock are either microphonic, noisy, loose bases, etc. But man when you find a good one they sure are sweet sounding.

[@TheGuitologist]

Yep! I agree. The pentode octals are particularly troublesome, but damn they can sound so good.

[@sfv1001]

Damn, I just bought that same style voltage display meter (DC) version recently. Good to know I think a little bit like the Guitologist!!

[@ReverendHellbilly]

These are my favorite vids you do,cheers

[@JC-11111]

Nice find on those jacks, Brad! 👍

[@kensolo6793]

Hi Brad - great to see you back to doing your thing your way! Ive missed these vids. Great video, very interesting and informative. Thank you!!

[@TheGuitologist]

More to come! Stay tuned.

[@marknash7113]

Wow! Set the wayback machine for 1953 Brad, Iv'e been Teleported back! Sounds killer and is dead quiet! Great work!

[@Robster-Craw]

I bet it sounds wonderful in person. KZbin just doesn't do a lot of these amps any justice. I play a crate bv120h through an old 70s Sunn 4x12. it's so fun to play. Those amp heads don't get enough appreciation or my speakers are just so awesome they make turds sound like top tier gear? Either way, Crank that bad boy and it's so chunky and loud. Such a good natural drive on the clean channel dimed. You can lean into the sound it moves so much air.

[@DavesGuitarChannel]

Great video Brad. This was a fun watch.

[@TheGuitologist]

Thanks Dave. Glad you enjoyed it.

[@pauldavis6356]

Nigel Tufnel - "These amps go to 11" Brad The Guitologist - "Well my Twin goes to 12 so there. Hmff."

[@samuellord8576]

Brad: "My Twin goes to *two* twelves"

[@erikvaldur3334]

Holy high end batman. Wow that Tele is bright in this amp.i know they're typically bright but I've not listened to them much. That PRS knocked down the highs quite a bit.

[@patrickinthesmokys5165]

this is why i subscribed..tx Brad!

[@lroy730]

What a great amp adventure! Wish I could work on apps like I used to. Now I do is work on guitars. Anyway great video Brad

[@TheGuitologist]

Hey dude. Good to see you.

[@lroy730]

@@TheGuitologist right back at you Brad. Here in La reporting from the Apocalypse. Still working never get sick. Just have to put up with a bunch of a-holes. So-so average day in La not much has changed.

[@russlachapelle1579]

Excellent video Brad for so many reasons... touche

[@TheGuitologist]

Thanks, Russ! I appreciate you saying so.

[@Drzingo]

Nice work Brad, top notch!

[@thomasgwilliams7957]

Great job Brad! Thanks man for the lesson and the 1984 tribute!

[@daveesco1]

Now this is the Brad I want to see . Love ya dude. Still say you have every right to voice your opinion on political stuff, set up a separate channel for that. It would really do well for those that like to discuss political stuff.

[@Zeinzu2]

Fantastic segment/topic . Plenty of people on KZbin show and play these thing. Giving us the TONES!!!! And that's all well and good. We all benefit watching those vids. But there's always more to the story. You going through, and giving us the history the way you do, is also just as important to the full story of these amps. Personally: I LOVE THIS SHIT, hahahah. Good to see you digging into your interests a little more. Great stuff, man!! Cheers from Akron, Ohio.

[@TheGuitologist]

Thanks for that. I'm really glad you enjoyed this one. I put a lot of work into it.

[@cgavin1]

Old video but this was really enjoyable to follow along with your troubleshooting. I think ultimately you struck an amazing balance between originality and functionality. Its pretty crazy how we went from this kind of "twin" to the AB763 in just a few years. You'd think it would have been the other way around given what they were doing musically in the 50's. 😁

[@fatsuperfly]

I would love to play one of those amps, I’m a metal guy and can’t play what you play to give it justice. But damn am I jelly. Love these vids bro, thank you again for all the great content.

[@lutboy2909]

That amp scream for old good stuff like bb king or Eric clapton, the sound of this is sick good job bro keep doing this I enjoyed all the video

[@TheGuitologist]

I'm getting a Freddie King vibe from it.

[@gerryloughran1676]

Cool you got some staying power to sort that out ...well done

[@CoolestMcGuy]

Glad to see you back! hope all is going well

[@thetoneknob4493]

i swear to god wen you said 1953 fender twin my dogs ears perked up and he sat down became very interested and watched for the better part of 15 mins before he had dog stuff he had to do and wandered off but i must say that's pretty darn impressive!

[@TheGuitologist]

hahaha! Maybe he's the reincarnation of Rusty.

[@williambock1821]

The Guitologist RUSTYYYYYYY!!!!🥺

[@jasonwright7513]

Man that amp has got mojo. You know why so many top players use them. I had a 25 watt version from ceriatone that I put in a 112 cabinet. I sold it a while ago , great amp that tweed circuit.

[@electroKrunch]

Brad... I'm so glad to be back.... I've ventured off into Bullshit Land and are now finding my roots back with Brad....

[@theguitaramptech]

Nice work, Brad. I really like the look of the blue Sozo caps all nicely aligned. Top class, mate.

[@rockyou42560]

Sound is great with prs ❤️ amazing job dude !

[@moonboogien8908]

You are the coolest fixer-upper on KZbin.

[@TheGuitologist]

Thanks. Nice of you to say.

[@rayjamesevilgenius5465]

Hey Brad, Oddly enough, at the 5:50 mark of your video, you can see a "550" stamp on teh the right speakerl frame. The white "550" ink stamp was a code that went on all speakers in Valco amps back in the day. I don't know if Valco put the stamp on there, or if Jensen did, but it's factual, all Valco amps had a 550 speaker stamp, whether they were from Rola or Jensen. Leads me to think someone may have pulled these from a Valco amp to replace blown originals.

[@RedGibsonsRock]

Valco definitely liked using P12P's. I've got 2 of them in my '63 Supro 1688T and one in my '54 Gretsch Electromatic.

[@rayjamesevilgenius5465]

@@RedGibsonsRock Their PM (alnico) speakers are great. I've stuck P15Ns in all my Thunderbolts. I started buying them up years ago in the used market for future replacement. The coils seem stout enough, but after all these years, they can be prone to develop mechanical problems-- vibrations, buzzing etc., as glues get more brittle and give up their bond.

[@TheGuitologist]

Thanks, and upon review, you're right.

[@tonyduncan9852]

Bearing in mind that speaker technology has progressed in materials and industrial design over sixty years, it seems that later replacements, even of different manufacture, could only refine and improve on the sound originating from the original electronic 'recipe'.

[@toddweaversound]

That thing has some mojo man! It doesn't hurt to have you playing that tele through it at all. I was screaming at my screen about halfway into the video about the unshielded tubes vs original, the crap original filament wiring, and the need for a virtual centertap. Why did you decide to put the VCT on the power tube cathode? What advantage is there over just popping one off of the pilot lamp? Three of those input jacks looked like non-switching from angle of the video, you found out there were two and you nailed it. I wonder how quiet the amp would have actually been with just the input jacks actually grounding properly before you did all of that other stuff. At any rate, that thing has been made right!

[@dieterdeclercq]

He’s elevating the reference voltage for the VCT from gnd to a higher voltage (typically around 40-50V). The cathode of a cathode-biased power tube is a convenient location for such a voltage. The heaters still operate at 6.3V but this floats on top of the elevated voltage. This is not always needed, but the elevation can reduce hum by reducing current between heater and cathode. Also the heater supply draws no current from the cathode so bias should remain unaffected (contrary to what Brad thought at first) Creating a VCT to gnd is indeed more convenient at the pilot light...

[@TheGuitologist]

Good thread. The best place in this instance seemed to be the power tube socket. I already had the ground connection right there on one of the pins, and the access to the cathode pin made it best for tying to that point. And Dieter is correct, the change in reference for the VCT means that any stray hum left in that 6.3V circuit will not be introduced into the chassis ground (where the input jacks are). In this case, it was throwing the bias off for some reason. In hindsight, I could have simply re-biased the output and left the VCT on the cathode, but I think the results were more than satisfactory by going to chassis ground, as this amp was DEAD quiet at idle after sorting the input jacks.

[@brich2929]

Excellent video, Brad! You knocked it out of the park with this one!

[@TheGuitologist]

I appreciate that! Thanks for saying so.

[@dougsie8791]

Thanks Brad. I really enjoyed the video; lots of great information & history in this one.

[@TheGuitologist]

Glad you enjoyed it

[@nosmoking2933]

Ace video, Brad! 👍🏿

[@TheGuitologist]

Thanks. I appreciate you watching.

[@nosmoking2933]

@@TheGuitologist that's OK dude cuz you rock! Very sad is the death of EVH though.

[@motorosso3349]

I enjoyed the video. Trying to troubleshoot a noise problem should always start with a check of all the grounds (electronics 101!). Hopefully, your customer didn't end up paying for all the experimenting. It is easy to go off on a tangent. This isn't a criticism, just a comment. Very interesting story.

[@rayjamesevilgenius5465]

Earlier Jensens had a different style logo and label. I think these would be from 1963, based on the Jensen sticker. If so, this would coincide with when Valco had amps with two 12" speakers. I don't think these are original.

[@TheGuitologist]

I questioned this as well. You may be right.

[@buffdoc46]

You are right. These are 63. Should have P12R or P12Q ribbed frame baskets

[@douglasahern7907]

C12PS "C" = ceramic, 1960s.

[@blucheer8743]

Damn bro you do good work! And you play damn good! Great channel man!!

[@Chance-ry1hq]

What???? No drama crap???? It’s nice to see you making an interesting video again, and leaving the drama crap to the drama queens.