Happy new year Brad! These troubleshooting and repair vids are what brought me to your channel. Good to see a new one pop into my notifications. I watched so many that during Christmas break I decide to build a kit amp. For the first time working on an amp, I thought it went well, and the end result sounds killer. I was able to recall tons of knowledge from your channel. Keep up the good work my man!
Russell, I got a Mojotone Studio One, which is a 1 watt output head. The tone stack is loosely based off a JCM800 according to Mojotone. Sounds great to my ears. Clean channel has a 12AY7, and the dirty channel uses two 12ax7’s. Output section uses a single 12bh7. It’s Diode rectified. I really liked it as a first build, but I will say that soldering small 9pin tube sockets takes a little practice for a newbie. Definitely not a small sounding amp through a 4x12, just much tamer on volume.
Russell E Simonetta, that’s a good idea. I’ll have to get on there and take a look. It’s fun being able to learn a new skill like this. Hopefully do another one in a few months. The wife is gonna love it lol.
All of a sudden, the pc board design made sense to me once you mentioned that Magnavox owned Ampeg at this time. I took apart a 1964-ish Magnavox console stereo and made a blackface Fender Champ out of it, but the pc board used on the radio portion has the exact same sort of design and orientation. The board on this radio was soldered to the chassis, which made things even more difficult. Basically, Ampeg used this design of circuit board because Magnavox used it.
My old roommate, the renowned amp guru Frank Levi III once told me that the 6u10 tubes don't hold up to the continuous hot internal climate of the amp, the adjacent tubes, and the rising heat from the upside down 6u10. And it's squatty wide girth so close to the pcb. The pcb actually retained the tubes heat. He said the Magnavox TV factory was where they built the amps, and since tube TV's rarely had tubes in upside down locations (let alone with 4 or more beam power-amp tubes heating things up), the engineers were surprised the amps were as reliable as they even were! They sure sound great though. I've gigged with several. As far as solid state amps, the Ampeg G110 fet based, guitar combo amp is so damn dynamic! Great clean to dirty picking attack. Nothing sterile or cardboard about it. Just a raw no-eq'ed acoustic guitar piezo pick-up sounds great through it. Excellent reverb and tremolo too.
You have no strain relief on the power cord you added. If you're going to do it wrong and use a grommet instead, you should at least tie a knot in it so it doesn't pull out the first time somebody trips over the cord.
Blue line graphics on Ampeg usually means first run 68/69. They changed to black with sharp corners in 70 and then softened the corners on the logo by 75
I have not closely inspected date codes on this other than the cap I show with a 1968 date code. I'm beginning to this this is late 1968 or early 1969 and therefore first run of this amp, because [SPOILER ALERT] the speaker turns out not to be original to this amp as I suspected it might not be.
It's interesting though that you saw a 72 date code on the transformer. If it's not a replaced Transformer, then that muddles things up a bit...I would think the OEM speaker would've been a square back CTS or something like that.
A few months back I bought a HeathKit hifi amp to convert into a 2203/2204 JCM800 style circuit. 2x 6EU7's, a 12AX7 PI and a pair of 7591A's. Not quite what Marshall used lol, but it sounds killer into a Marshall cab. The Heathkit schematic has the 7591s really hot from the factory, which I imagine is for the clean headroom, and maybe because they probably didn't expect people to dime their hifi stereo. Anyway, I bet that Ampeg is going to be awesome when this one is done. Glad to see a project that isn't giving you an existential crisis
Happy new year! When I saw the broken AC Outlet and that the epoxy looked suspect, I think I'd have eliminated that jack in favor of a modern IEC AC entry module. Trim the panel and pop that sucker in. It's cheap insurance for only a few bucks. They even make them with built-in ground line chokes and fuses.
I only understand about 15% of what you're saying and I know you're already trying to cater to people that are not electrical engineers but I appreciate it and I'm learning. I think. I still get nervous doing pickup and pickguard swaps but someday I will tinker with amps and pedals with any luck. Thanks for showing the slow process, and the added music during soldering montages helps I'm glad you're getting good footage of each step, A+ lighting and camera angles you could produce videos for Sweetwater, HSN or QVC and make bank if you're ever hurting for cash. May the power of Jesus Christ be with you.
I own one of these amps... The speaker shown in this video is definitely original as mine has the exact speaker. Others I've seen also have this Jensen C12R ("C" for Ceramic magnet, 12" speaker, "R" designates 25 Watts)..... The GU-12 is a 15 Watt amp. The speaker easily handles the power output. The screws in all Ampegs of this era are called Clutch head screws. Yes, they are weird. Why Ampeg chose those types of screws is a curiosity.... they require a 5/32 Clutch bit or screwdriver. Most people change these to Phillips head screws as the are far more common and a phillips screwdriver is usually within reach. The Ampeg Logo, on this amp, in the video, is missing from the speaker grill.
Makes me miss that period of my life where I had an early 70s V4...definitely don't miss all its problems though...but damn that amp sounded awesome, and best reverb I've ever heard in an amp.
It certainly catches your attention, I have not noticed any other music throughout the whole video (maybe there isn't any other music?), but I stopped listening to whatever he was saying when this started playing.
I had one of those (but with a different speaker). It had an intermittent problem that made it sound anemic 90% of the time, but the 10% of the time the problem was absent it sounded amazing. I took it to my tech, but he couldn't locate the problem. So I had no choice but to get rid of it.
I have a VT-22 still going strong. The main issue is the pads lifting from the board from my experience. I had to also redo some grounds as it was noisy when I got it.
Happy 2019! Those screw heads were a industry blunder in the 70s! They were used in just about everything, from consumer electronics to the mobile home industry. Hated by the public! Is that a Baxandall tone stack? I thought the amp was naisaly sounding. Your overall view of what the amp is and needs to be, is spot on. These service videos are so incredible! I know you may be tired of doing them, but if it weren't for you and Uncle Doug, we, your loyal followers, would be without our hit of ampoholics fix. There are so many others who do excellent service repairs, but yours are like you are in the room with you looking over your shoulder. You give a honest appraisal of the mods that work the best for the money spent. Love ya! Thanxz
I had a 56 Chevy pick up that used those clutch screws to hold the fenders onto the bed. I bet if I tear apart the garage I might be able to find them :)
Hi, those fasteners were called clutch . I still have my old clutch driver from 48 years ago, and the Ampeg B25 head and bottom that went with, lol the bottom had 2 -15" CTS speakers
From Leo: I am in the same opinion as you about tubes hanging off bottom of a printed circuit board. The heat does not need to be concentrated on the board. I have worked on some early Fender Blues deluxe and Deville amps that the tube sockets had long metal legs that would suspend the tube sockets at least 3/4" off the boards. These old amps show no burning around the tubes and the solder is in good shape The inverted PC boards are a bad design but the extended tube sockets were a good method of overcoming the deficiency. I would like to find a source for those extended octal tube sockets, they could save a lot of aging vintage amps. I get the willies every time something comes in with a 6U10 tube. Anyone that has any wants a ton of money for it, even if it is weak.
Magnovox TV circuit boards of this same era looked identical and also had all sockets soldered to the circuit board... The traces are super delicate, too.
Brad, those side bolts are called "Clutch-head". You can find the frivers in many of those multi-tip screwdriver sets with one driver and two dozen bits that fit it. They usuallt come in a little silver blow-molded case with a hinged lid. Find 'rm online or at harbor freight. They used to be used in some foreign cars, and I've actually seen them used on old American carburetors.
These Ampegs came with CTS speakers with square magnets (a terrible honking sounding speaker IMO much better for bass) Optional were Altec Lansing which sounded magnificent .. basically a clean amp with lots of headroom.
Re flowing broken wave solder joints was 1/3 of my business when I had my repair shop. Wave solder was great for smaller components, Large components or things that got warm, not so much.
Hey Brad I watch a lot of yor videos, great work. The special driver bit you need for that Chassis screw is in the Harbor Frieght driver bit set (about $9).
I'd wanna rip that put and put a turret board in hahahaha. Wow. I love your documentation of so many amps.. Great stuff. But im not getting enough sleep I can't sleep because I'm watching like a binge watcher of whatever that's called? Um Netflix?
I remember playing through a friends Ampeg amp....it was a 2×12 and on the input it had guitar or accordion written .....it made a warm fuzzy sound, and with an overdrive it could really sing....really fat solo tone....but, very muddy trying to riff out.....still cool.....
Being that I'm OCD and fairly paranoid, I prob would've literally re-flowed every single joint on that board. There aren't a ton of components, so it wouldn't have been too much of a time suck. Plus I get a weird satisfaction out of watching old joints get fresh, shiny solder after 40 years
Thank you for showing the whole process. What was always missing in previous videos were the steps you took to get where you needed to be. It always seemed incomplete. Sped up, etc.. whatever. Just show the entire repair!!
I've got the same amp, the C12R was almost certainly the original speaker; that's what was used in this model. It was not up to the task of what rock guitar players were going to put it through. Ampeg didn't design amps for rock guitar players until a little bit later. They didn't expect people to push the volume past noon or so, I imagine. That said, once you replace the speaker, it is a remarkably good sounding amp. I've owned many, many Ampegs over the years (my first amp back in '72 was a brand new VT-40) and here in 2019, I have to say, the GU-12 is my favorite. It captures the "Ampeg sound" and basic personality of the VT-40 but in a much smaller, much more manageable format. BTW... the use of the bass and treble controls should be VERY notable. If they aren't, there's something wrong. That is a highly effective tone circuit. Here are a couple vids of mine: ruclips.net/video/HxAVc2bgcEs/видео.html ruclips.net/video/kHWtAJ-Wl5c/видео.html
@@TheGuitologist Sadly, true. Some companies are more than happy to provide one if you ask for it, but even they are few. I don't touch amps for repair just because I'm not that great with engineering. But I know enough to be able to look at a schematic and know what each tube is doing so I can be a bit judicious in selection.
Thanks Brad! I learn so much from watching your videos and they're amusing too. The straightforward approach in troubleshooting and fixing has inspired me to have a go at my own stuff, so keep up the good work and the no b.s. attitude. A word of caution though, please don't use a plastic strip as the only powercord retainer. I've seen them come loose many times ( electrician ) and you're the one responsible for the safety of the costumer. I'd use anything that clamps or squeezes by the force of a thread. Cheers and a Happy new Year! Jerker Fridh
Almost forgot... I suspect Ampeg designed the amp to be serviced with the top of the chassis on the bench, due to the end block "legs" being shock-mounted (which doesn't support the chassis very well on their own). IOW, what some consider a "fault" is really "by design" from the perspective of Ampeg at the time.
Not sure I'd trust epoxying that outlet. I think it's a pretty run of the mill appliance part. I remember replacing one years ago (can't remember what on) and finding one at the big orange box store.
"Hard" cracked me up! Alright Brad, you're telling us you couldn't fix this in a single vid? Just because Fran's Heath Kit build is going to take 5 vids to complete doesn't mean you can slack off! Maybe that Mesar Booger damaged your spirit. Only kidding. I love all your vids.
Schematic on the top cover was a wonderful idea. Also the layout on schematic was damn good the way they labeled the section to the related tube. Just finished watching this video and I don't really think I need it...uh...yeah...umm I think I'd like to return this. What's your refund policy?
Hope the Boogers revenge isn't too much trouble ;) Love for Ampeg started with "Get Yer Ya Yas Out", then a new release ('69 i believe, i was 12). Later in '73, a class mate stepped up his rig to a SG Standard and a V-4 full stack. Nice set up.
I don't know why but that the epoxy job is bothering me. I know you're the regular guys tube repair dude and all and I dig that about your channel. You should watch some silicone caulk/cornstarch cheap mold tech videos to learn how to quickly mold half broken parts n knobs.
Donald Robinson.... This is very good info for people with vintage Ampeg’s... My ‘73 810 has about five hundred 3/8" Clutch Head screws mounting all the drivers, which would’ve been a PITA for me to remove ‘em all with a flathead screwdriver or something...
I love that you are rerunning these, you didn’t lose me with your political views in ‘21, hopefully you are getting what you want from your channel again if you weren’t.🙂
Hello, i have a Gu12 with a replaced tremolo module. Tremolo works but doesn't get that pronounced. I'm interested if you can demo the tremolo range on that amp since it seems to have the original clairex photomod CL1110 ! Thx
I love seeing amps like this that seem really uncommon where I am. Board mounted tube sockets irk me though. I know lots of manufacturers have done it but given all the downsides and the overall design it makes me think reliability/serviceability much of a concern to them. Sure, it can be done alright with a proper design but more times than not it's just an attempt to pinch pennies where chassis mount would have been better. I don't mind so much when it's a seperate board like some of the Fender amps but generally it's just dumb. Of course I know I'm preaching to the choir here.
Always enjoy your videos! Quick question... I know the legend of the flat woods monster but is that a sticker for a band or some project you were involved with?
Hey Brad did you ever try J-B Weld 5-minute epoxy? It's a lot more versatile because he dries rock hard as opposed to the other epoxy which never really gets completely hard. And it's steel grey which always looks good.
Artie Saginario saw a vid the other day where a guy compared epoxy glues, several different brands. A couple were standout winners. Can't recall which.
My opinion on this amp is that it's not a '72 but a '69. Just because the Jensen is a '72 doesn't mean the amp is, I would wager that Jensen is a replacement. The cap with the 6846 date code coincides with the nickel-plated chassis '69 Ampegs. IME. By '72, they had already switched to black-painted chasses. So, that cap was likely not "old stock"/left-over; that amp's likely a '69.
Ahh no wonder my V4 can heat a small room! tubes that run hot, the V4 has these odd labeled jacks on the back, my interpretation was it was a way to link 2 V4’s together, is that right Brad? I did it on an 80 degree day, they both became too hot to touch the chassis, my friend who owned the second one got nervous. But his was driving a 4 x12, mine was driving a Carvin Vega 18”. Fabulous bass tone, louder than the SVT together
Those be Clutch Head screws which have been savaged by years of screwdriver miscegenation. Collectors of vintage Ampegs often prefer to see the original screws and the drivers are available at Amazon.
Beat me to it. Those clutch head screws were once common to mobile homes. Almost nobody went to he trouble of getting the bit for them. They just stuck a flat screwdriver in them.
You Yanks should have adopted the Robertson screw (square drive) invented here in Ontario. When using the proper size driver you will break off the head of the screw before stripping the socket - unlike the Phillips which strips if you look at it sideways.
Just did an old VT22 with a 6K11 compactron. Some of those old V4/VT22's had the compactrons and some didn't. Must be Magnavox had a glut of them and engineered the amps to use them up from changing TV technology. It had a lot of PCB issues I had to fix.
Good call on the Magnavox connection and Compactron. GE also had a factory in Skenekdedy, or however you spell that. Also a factory in Kentucky, not far from Magnavox Indiana plant.
@@TheGuitologist Schenectady LOL! Yeah I live about 3 hours from there. GE used to have a foundry 5 minutes from my home. The good old days where things were booming before and after the war. My dad worked at a local Westinghouse plant a few minutes away and my mom worked at the biggest A+P food processing plant on the east cost a few minutes away when A+P was a household name. I live 15 minutes from Corning Inc.( Corning Glass Works) who became famous for Pyrex back in the day and Corelle dishes. They now make all the gorilla glass flat panel TV screens and fiber optics. If I would have had a clue about tubes when I was a kid my dad could have gotten 1000's of 12AX7's and all the power tubes I would ever need. I'd be a rich man with all the NOS tubes he could have gotten for pennies back then.
Upside down valves? All the electrons will fall out! It's a pity manufacturers no longer include the schematic like that, I guess everything is now a single chip solution!
The factory is still there! You should go ask the current occupant if you can do a quick film for historical purposes and upload to RUclips! I'd watch that.
Can someone tell me how to have him fix my slightly older Fender Silver Face Twin? Compared to that MESA fix/repair this should be an easy Repair/Mod ready amp! He is my favorite TECH! Thank you Brad, ESJ
It’s called a clutch head screw and the bit is obviously a clutch head screwdriver bit. I’m lucky enough to have the correct screwdriver cuz they are hard to find
Harbor Freight grommet collection.. FLEX!
That B2B scene is the seed that planted my desire to play guitar.
Happy new year Brad! These troubleshooting and repair vids are what brought me to your channel. Good to see a new one pop into my notifications. I watched so many that during Christmas break I decide to build a kit amp. For the first time working on an amp, I thought it went well, and the end result sounds killer. I was able to recall tons of knowledge from your channel. Keep up the good work my man!
Awesome, Dan! Congrats!
Russell, I got a Mojotone Studio One, which is a 1 watt output head. The tone stack is loosely based off a JCM800 according to Mojotone. Sounds great to my ears. Clean channel has a 12AY7, and the dirty channel uses two 12ax7’s. Output section uses a single 12bh7. It’s Diode rectified. I really liked it as a first build, but I will say that soldering small 9pin tube sockets takes a little practice for a newbie. Definitely not a small sounding amp through a 4x12, just much tamer on volume.
Russell E Simonetta, that’s a good idea. I’ll have to get on there and take a look. It’s fun being able to learn a new skill like this. Hopefully do another one in a few months. The wife is gonna love it lol.
The design of this amp is very thoughtful for serviceman. Accessible from the top and bottom. Thumbs up Ampeg. Great video sir.
All of a sudden, the pc board design made sense to me once you mentioned that Magnavox owned Ampeg at this time. I took apart a 1964-ish Magnavox console stereo and made a blackface Fender Champ out of it, but the pc board used on the radio portion has the exact same sort of design and orientation. The board on this radio was soldered to the chassis, which made things even more difficult. Basically, Ampeg used this design of circuit board because Magnavox used it.
Who the flex is giving this a thumbs down? I was hoping we wouldn't have so many thumbsuckers this year... oh well, great video Brad! Carry on!
My old roommate, the renowned amp guru Frank Levi III once told me that the 6u10 tubes don't hold up to the continuous hot internal climate of the amp, the adjacent tubes, and the rising heat from the upside down 6u10. And it's squatty wide girth so close to the pcb. The pcb actually retained the tubes heat. He said the Magnavox TV factory was where they built the amps, and since tube TV's rarely had tubes in upside down locations (let alone with 4 or more beam power-amp tubes heating things up), the engineers were surprised the amps were as reliable as they even were! They sure sound great though. I've gigged with several.
As far as solid state amps, the Ampeg G110 fet based, guitar combo amp is so damn dynamic! Great clean to dirty picking attack. Nothing sterile or cardboard about it. Just a raw no-eq'ed acoustic guitar piezo pick-up sounds great through it. Excellent reverb and tremolo too.
You have no strain relief on the power cord you added. If you're going to do it wrong and use a grommet instead, you should at least tie a knot in it so it doesn't pull out the first time somebody trips over the cord.
I just finished watching "Back to the future" trilogy and you hit me with that intro.
Blue line graphics on Ampeg usually means first run 68/69. They changed to black with sharp corners in 70 and then softened the corners on the logo by 75
I have not closely inspected date codes on this other than the cap I show with a 1968 date code. I'm beginning to this this is late 1968 or early 1969 and therefore first run of this amp, because [SPOILER ALERT] the speaker turns out not to be original to this amp as I suspected it might not be.
It's interesting though that you saw a 72 date code on the transformer. If it's not a replaced Transformer, then that muddles things up a bit...I would think the OEM speaker would've been a square back CTS or something like that.
Flex
Ok, good. Back to regularly scheduled programming!
A few months back I bought a HeathKit hifi amp to convert into a 2203/2204 JCM800 style circuit. 2x 6EU7's, a 12AX7 PI and a pair of 7591A's. Not quite what Marshall used lol, but it sounds killer into a Marshall cab. The Heathkit schematic has the 7591s really hot from the factory, which I imagine is for the clean headroom, and maybe because they probably didn't expect people to dime their hifi stereo. Anyway, I bet that Ampeg is going to be awesome when this one is done. Glad to see a project that isn't giving you an existential crisis
Happy new year! When I saw the broken AC Outlet and that the epoxy looked suspect, I think I'd have eliminated that jack in favor of a modern IEC AC entry module. Trim the panel and pop that sucker in. It's cheap insurance for only a few bucks. They even make them with built-in ground line chokes and fuses.
First vacation I’ve had in years, and this is what I’m doing! Love these old ampegs, thanks for sharing.
I only understand about 15% of what you're saying and I know you're already trying to cater to people that are not electrical engineers but I appreciate it and I'm learning. I think. I still get nervous doing pickup and pickguard swaps but someday I will tinker with amps and pedals with any luck. Thanks for showing the slow process, and the added music during soldering montages helps I'm glad you're getting good footage of each step, A+ lighting and camera angles you could produce videos for Sweetwater, HSN or QVC and make bank if you're ever hurting for cash. May the power of Jesus Christ be with you.
I own one of these amps... The speaker shown in this video is definitely original as mine has the exact speaker. Others I've seen also have this Jensen C12R ("C" for Ceramic magnet, 12" speaker, "R" designates 25 Watts)..... The GU-12 is a 15 Watt amp. The speaker easily handles the power output. The screws in all Ampegs of this era are called Clutch head screws. Yes, they are weird. Why Ampeg chose those types of screws is a curiosity.... they require a 5/32 Clutch bit or screwdriver. Most people change these to Phillips head screws as the are far more common and a phillips screwdriver is usually within reach. The Ampeg Logo, on this amp, in the video, is missing from the speaker grill.
The actress who's playing your toddler sounds adorable lol.
LightningDogg she's very convincing. Even wakes me up in the middle of the night. Method actor! :)
Makes me miss that period of my life where I had an early 70s V4...definitely don't miss all its problems though...but damn that amp sounded awesome, and best reverb I've ever heard in an amp.
Interesting version of Nirvana's Lounge Act at 22:40.
Brad has covered the whole album!
@@mstecker Ah cool. Good taste!
@@PaulJoy Search for Electric Tooth Syndrome "Whatever, Nevermind". You'll find the whole thing.
I also thought to myself - what is this zorba nirvana stuff?
It certainly catches your attention, I have not noticed any other music throughout the whole video (maybe there isn't any other music?), but I stopped listening to whatever he was saying when this started playing.
I had one of those (but with a different speaker). It had an intermittent problem that made it sound anemic 90% of the time, but the 10% of the time the problem was absent it sounded amazing. I took it to my tech, but he couldn't locate the problem. So I had no choice but to get rid of it.
I had the same problem, had to let it go.
I have a VT-22 still going strong. The main issue is the pads lifting from the board from my experience. I had to also redo some grounds as it was noisy when I got it.
Thanks Brad, interesting, informative and humorous yet again. Much appreciated.
Happy 2019! Those screw heads were a industry blunder in the 70s! They were used in just about everything, from consumer electronics to the mobile home industry. Hated by the public! Is that a Baxandall tone stack? I thought the amp was naisaly sounding. Your overall view of what the amp is and needs to be, is spot on. These service videos are so incredible! I know you may be tired of doing them, but if it weren't for you and Uncle Doug, we, your loyal followers, would be without our hit of ampoholics fix. There are so many others who do excellent service repairs, but yours are like you are in the room with you looking over your shoulder. You give a honest appraisal of the mods that work the best for the money spent. Love ya! Thanxz
Your chassis screws on the side of the case are called "Double D" in the old automotive world. lol
Brad, Great video! I hope it makes you 9k this month.
Commonly know as clutch head screws.
I had a 56 Chevy pick up that used those clutch screws to hold the fenders onto the bed. I bet if I tear apart the garage I might be able to find them :)
Very common in/on Campers & older truck caps.
Clutch head...double Ds...sounds about right. :)
Ampeg also used a 6K11 compactron tube in the V4 series amps for an active midrange control it's pretty cool and interesting
Hi, those fasteners were called clutch . I still have my old clutch driver from 48 years ago, and the Ampeg B25 head and bottom that went with, lol
the bottom had 2 -15" CTS speakers
From Leo: I am in the same opinion as you about tubes hanging off bottom of a printed circuit board. The heat does not need to be concentrated on the board. I have worked on some early Fender Blues deluxe and Deville amps that the tube sockets had long metal legs that would suspend the tube sockets at least 3/4" off the boards. These old amps show no burning around the tubes and the solder is in good shape The inverted PC boards are a bad design but the extended tube sockets were a good method of overcoming the deficiency. I would like to find a source for those extended octal tube sockets, they could save a lot of aging vintage amps.
I get the willies every time something comes in with a 6U10 tube. Anyone that has any wants a ton of money for it, even if it is weak.
Magnovox TV circuit boards of this same era looked identical and also had all sockets soldered to the circuit board...
The traces are super delicate, too.
Brad, those side bolts are called "Clutch-head". You can find the frivers in many of those multi-tip screwdriver sets with one driver and two dozen bits that fit it. They usuallt come in a little silver blow-molded case with a hinged lid. Find 'rm online or at harbor freight. They used to be used in some foreign cars, and I've actually seen them used on old American carburetors.
Back in the day every mobile home had clutch head screws in everything lol. I have so many I can't find them anymore lol.
These Ampegs came with CTS speakers with square magnets (a terrible honking sounding speaker IMO much better for bass) Optional were Altec Lansing which sounded magnificent .. basically a clean amp with lots of headroom.
The only Channel I don't fast forward thought the sponsor portion of the video.
Re flowing broken wave solder joints was 1/3 of my business when I had my repair shop. Wave solder was great for smaller components, Large components or things that got warm, not so much.
Hey Brad I watch a lot of yor videos, great work. The special driver bit you need for that Chassis screw is in the Harbor Frieght driver bit set (about $9).
Man, I love your videos. I learn something new every time. Thanks for all your hard work!
Peavey used compactron tubes in the early 70s vintage, which was a tweed bassman copy with reverb and 100 watts.
Ampeg: An interesting way of doing things. Never seen the inside of one before, interesting to see how things are done half way around the world.
I'd wanna rip that put and put a turret board in hahahaha. Wow.
I love your documentation of so many amps.. Great stuff.
But im not getting enough sleep I can't sleep because I'm watching like a binge watcher of whatever that's called? Um Netflix?
Thanks for watching.
I picked up one of these off of Offer Up for $100 with all of the original paperwork and hangtags and other goodies. I flipped it for around $350.
I remember playing through a friends Ampeg amp....it was a 2×12 and on the input it had guitar or accordion written .....it made a warm fuzzy sound, and with an overdrive it could really sing....really fat solo tone....but, very muddy trying to riff out.....still cool.....
The 70s ones you can usually dial in enough midrange to get a nice AC/DC Marshall tone.
Being that I'm OCD and fairly paranoid, I prob would've literally re-flowed every single joint on that board. There aren't a ton of components, so it wouldn't have been too much of a time suck. Plus I get a weird satisfaction out of watching old joints get fresh, shiny solder after 40 years
Thank you for showing the whole process. What was always missing in previous videos were the steps you took to get where you
needed to be. It always seemed incomplete. Sped up, etc.. whatever. Just show the entire repair!!
I hate it when my things get jostled. Happy New Year to you and all those You Love.
I've got the same amp, the C12R was almost certainly the original speaker; that's what was used in this model. It was not up to the task of what rock guitar players were going to put it through. Ampeg didn't design amps for rock guitar players until a little bit later. They didn't expect people to push the volume past noon or so, I imagine.
That said, once you replace the speaker, it is a remarkably good sounding amp. I've owned many, many Ampegs over the years (my first amp back in '72 was a brand new VT-40) and here in 2019, I have to say, the GU-12 is my favorite. It captures the "Ampeg sound" and basic personality of the VT-40 but in a much smaller, much more manageable format.
BTW... the use of the bass and treble controls should be VERY notable. If they aren't, there's something wrong. That is a highly effective tone circuit.
Here are a couple vids of mine:
ruclips.net/video/HxAVc2bgcEs/видео.html
ruclips.net/video/kHWtAJ-Wl5c/видео.html
Good vid Brad and looking forward to part two, as this is sounding like it could end up a nice little combo ... Happy New Year !
You can find the screwdriver for those screws at a mobile home parts shop. The trailer I grew up in had those everywhere.
Happy new year brad. yep gotta help the little 1s. :-)
they are clutch head screws,I have many Ampeg amps of that era,the screwdrivers are still avable.
@@goodun6081 Damn. Sorry I missed that deal.
I will look for my clutch driver collection. I only ever used one on a 1960s Ford dashboard radio. Decades ago.
Wow, I'm impressed. That thing sounds awesome!
That's one thing I wish they would still do in this decade. Include a schematic. Whether it's a pedal, an amp, anything.
Isher they won't unless consumers learn to demand it again.
@@TheGuitologist Sadly, true.
Some companies are more than happy to provide one if you ask for it, but even they are few. I don't touch amps for repair just because I'm not that great with engineering. But I know enough to be able to look at a schematic and know what each tube is doing so I can be a bit judicious in selection.
A thought, using the 1 minute epoxy in the tubes, mixes in the tube and goes into place nicely, no messy fingers and work bench, i love the stuff
Thanks Brad! I learn so much from watching your videos and they're amusing too. The straightforward approach in troubleshooting and fixing has inspired me to have a go at my own stuff, so keep up the good work and the no b.s. attitude. A word of caution though, please don't use a plastic strip as the only powercord retainer. I've seen them come loose many times ( electrician ) and you're the one responsible for the safety of the costumer. I'd use anything that clamps or squeezes by the force of a thread.
Cheers and a Happy new Year!
Jerker Fridh
Great Video Brad!Never should have sold my Ampeg Rocket, even though it was the first amp to shock me . Much has been learned since then!
This is exactly how all of my damn repairs end lol
Good vid Brad ... Hurry up with part 2 ... Them darn kids ... Lol ...
Almost forgot... I suspect Ampeg designed the amp to be serviced with the top of the chassis on the bench, due to the end block "legs" being shock-mounted (which doesn't support the chassis very well on their own). IOW, what some consider a "fault" is really "by design" from the perspective of Ampeg at the time.
PCBs should all be foil and components up. BGW knew this in the '70s - super easy to service. But at least this amp has the trap door.
Ahhh a good standard amp maintenance video. Great stuff. Comforting somehow. And I'm still loving my Native Sons strap on my p-bass.
Not sure I'd trust epoxying that outlet. I think it's a pretty run of the mill appliance part. I remember replacing one years ago (can't remember what on) and finding one at the big orange box store.
It's pretty well on there. I don't see it going anywhere unless someone just takes a chisel to it.
"Hard" cracked me up! Alright Brad, you're telling us you couldn't fix this in a single vid? Just because Fran's Heath Kit build is going to take 5 vids to complete doesn't mean you can slack off! Maybe that Mesar Booger damaged your spirit. Only kidding. I love all your vids.
Back to the future intro:)
Schematic on the top cover was a wonderful idea. Also the layout on schematic was damn good the way they labeled the section to the related tube. Just finished watching this video and I don't really think I need it...uh...yeah...umm I think I'd like to return this. What's your refund policy?
Tommy conan Coates returns permitted and encouraged...100% restock fee.
Hope the Boogers revenge isn't too much trouble ;) Love for Ampeg started with "Get Yer Ya Yas Out", then a new release ('69 i believe, i was 12). Later in '73, a class mate stepped up his rig to a SG Standard and a V-4 full stack. Nice set up.
I don't know why but that the epoxy job is bothering me. I know you're the regular guys tube repair dude and all and I dig that about your channel. You should watch some silicone caulk/cornstarch cheap mold tech videos to learn how to quickly mold half broken parts n knobs.
Enjoying this so far. All the best for 2019 from Hobbiton NZ
The proper name for those fasteners are called clutch head screws
Donald Robinson.... This is very good info for people with vintage Ampeg’s... My ‘73 810 has about five hundred 3/8" Clutch Head screws mounting all the drivers, which would’ve been a PITA for me to remove ‘em all with a flathead screwdriver or something...
Much respect for the Nirvana.
I didn't know that 6U10, 12DW7 and 7591 were all TV tubes or used in TV. I wonder why Ampeg used TV tubes from guitar amplifiers.
I love that you are rerunning these, you didn’t lose me with your political views in ‘21, hopefully you are getting what you want from your channel again
if you weren’t.🙂
amazing to watch you do this
Hello, i have a Gu12 with a replaced tremolo module. Tremolo works but doesn't get that pronounced. I'm interested if you can demo the tremolo range on that amp since it seems to have the original clairex photomod CL1110 ! Thx
I love seeing amps like this that seem really uncommon where I am. Board mounted tube sockets irk me though. I know lots of manufacturers have done it but given all the downsides and the overall design it makes me think reliability/serviceability much of a concern to them. Sure, it can be done alright with a proper design but more times than not it's just an attempt to pinch pennies where chassis mount would have been better. I don't mind so much when it's a seperate board like some of the Fender amps but generally it's just dumb. Of course I know I'm preaching to the choir here.
Really digging the drum and bass in the background! 👍
6u10 were also in Fender amps designed by Rivera,beginning of 80s
Hey Brad, what's the music around 14:30 - 17:40?
The owner should probably stock up some of those compactrons, they seem obsolete, even for tubes.
did you try an allen wrench to remove them bolts? Looks like a hex slot that too many people used slotted screwdrivers instead of hex bits...
I'm hoping the customer will want you to increase the volume*...
Looking f'ward to part two.
*(if poss.)
thanx for a great vid, Brad and...
cheers
Always enjoy your videos! Quick question... I know the legend of the flat woods monster but is that a sticker for a band or some project you were involved with?
My Ampeg V-4 cabinet has Jensen speakers and the backplate says "Loaded with Jensen speakers" so that is more than likely an original speaker.
At least it has that access plate on the other side
It has a back door, but you have to pull some nuts to get in it.
Hey Brad did you ever try J-B Weld 5-minute epoxy? It's a lot more versatile because he dries rock hard as opposed to the other epoxy which never really gets completely hard. And it's steel grey which always looks good.
Artie Saginario saw a vid the other day where a guy compared epoxy glues, several different brands. A couple were standout winners. Can't recall which.
I do recall the quick stuff was the worst.
My opinion on this amp is that it's not a '72 but a '69. Just because the Jensen is a '72 doesn't mean the amp is, I would wager that Jensen is a replacement. The cap with the 6846 date code coincides with the nickel-plated chassis '69 Ampegs. IME. By '72, they had already switched to black-painted chasses. So, that cap was likely not "old stock"/left-over; that amp's likely a '69.
Brad, when will you be pulling out your recently acquired Gold Les Paul Classic for some demo action?
At least they put an access panel on the component side of the pcb. Unlike a Mesa Booger.
Those might be messed up clutch head screws.
"Daddy!" - stopped. ROFL.
Ahh no wonder my V4 can heat a small room! tubes that run hot, the V4 has these odd labeled jacks on the back, my interpretation was it was a way to link 2 V4’s together, is that right Brad? I did it on an 80 degree day, they both became too hot to touch the chassis, my friend who owned the second one got nervous. But his was driving a
4 x12, mine was driving a Carvin Vega 18”. Fabulous bass tone, louder than the SVT together
Those be Clutch Head screws which have been savaged by years of screwdriver miscegenation. Collectors of vintage Ampegs often prefer to see the original screws and the drivers are available at Amazon.
"These screws is miscegenated!!!! Is you is or is you ain't a flathead?!?!"
Beat me to it. Those clutch head screws were once common to mobile homes. Almost nobody went to he trouble of getting the bit for them. They just stuck a flat screwdriver in them.
Also called "elephant ear" screws I think ?
You Yanks should have adopted the Robertson screw (square drive) invented here in Ontario. When using the proper size driver you will break off the head of the screw before stripping the socket - unlike the Phillips which strips if you look at it sideways.
@@garylenius4181 We have square drive.
Just did an old VT22 with a 6K11 compactron. Some of those old V4/VT22's had the compactrons and some didn't. Must be Magnavox had a glut of them and engineered the amps to use them up from changing TV technology. It had a lot of PCB issues I had to fix.
Good call on the Magnavox connection and Compactron. GE also had a factory in Skenekdedy, or however you spell that. Also a factory in Kentucky, not far from Magnavox Indiana plant.
@@TheGuitologist Schenectady LOL! Yeah I live about 3 hours from there. GE used to have a foundry 5 minutes from my home. The good old days where things were booming before and after the war. My dad worked at a local Westinghouse plant a few minutes away and my mom worked at the biggest A+P food processing plant on the east cost a few minutes away when A+P was a household name. I live 15 minutes from Corning Inc.( Corning Glass Works) who became famous for Pyrex back in the day and Corelle dishes. They now make all the gorilla glass flat panel TV screens and fiber optics. If I would have had a clue about tubes when I was a kid my dad could have gotten 1000's of 12AX7's and all the power tubes I would ever need. I'd be a rich man with all the NOS tubes he could have gotten for pennies back then.
Upside down valves? All the electrons will fall out! It's a pity manufacturers no longer include the schematic like that, I guess everything is now a single chip solution!
Hey Brad, cool video as always. Say, what was that song while you resoldered the tube sockets?
Neat, I live rite next to linden. Wasn’t aware they were ever made in NJ.
My first guitar amp (in 1959) was a 1x12 Ampeg Jet, from Linden, very near my home in Summit.
Google "Jess Oliver" who was the tech wizard at Ampeg in the 50's. He designed the Porta Flex bass line.
The factory is still there! You should go ask the current occupant if you can do a quick film for historical purposes and upload to RUclips! I'd watch that.
I'm near Linden the one in Texas. A lot if music from here.
@@TheGuitologist I'll give it a shot, worse thing that can happen is I get shot.
I'm pretty sure, in the 70's, Ampegs had Jensen speakers. I know of a couple, at least that had Jensens.
J.B. Weld man, not epoxy! lol. Nice job but not enough flexing.
I got to flex my strippers. ;)
Jb weld is epoxy.
I have a question what wire cutters are those? I’m an avionics tech and those seem perfect for my job and this work too.
The ones I have are Ripley. Made in USA. There are crappy knock offs out there too, but here are the Ripleys:
amzn.to/2RnMh95
Actually, mine are Model 100, now that I look. The ones in the link are close, but slightly different.
Thank you so much!
Hey brad ,is your music on SoundCloud or anything ? Think I asked before but can’t remember where to find it.
I have 3 albums on RUclips. Or you can listen here: www.reverbnation.com/electrictoothsyndrome/songs
Gracias
Just do a simple 0 mod on your variac LCD !!! You will be able to monitor between 0-65 volts as well. 10 minutes mod and there you go!
Can someone tell me how to have him fix my slightly older Fender Silver Face Twin? Compared to that MESA fix/repair this should be an easy Repair/Mod ready amp! He is my favorite TECH! Thank you Brad, ESJ
Try using a square tipped robertson driver for those dumbass screws they used.
It’s called a clutch head screw and the bit is obviously a clutch head screwdriver bit. I’m lucky enough to have the correct screwdriver cuz they are hard to find
I believe magnovox was bought by Phillips or visa versa, hence the European parts.