How to repair silver face Fender champ 6V6 Tube amp Theater D-lab electronics Old school technology
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- เผยแพร่เมื่อ 10 ธ.ค. 2016
- Opening, transform a solid state robot to a Tube amp theater Tubot. He has risen and roams the halls of D-lab. The Tubot is powered by a zed-pm. His powers are limitless! This silver champ was in pretty poor condition. Lucky for the owner, both power and output transformers were still OK. These old amp keep kicking out the tunes, Still the go to amp for many recording artists. Hope you enjoy this fine d-lab presentation.
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Very enjoyable. I've got a 1974( I think) silverface that needs servicing. I don't think it's ever been touched.
Thanks Terry, another great repair. I always look forward to seeing your fine work keeping these old amps going.
Great job professor! I can't wait to crank her up. Thank you for the fine and honest work!
Like iv heard you say before-lets get all those old CIGAR Buts ahda there!. Tube amp theeitah.
Great Terry! Every tube amp repair is a "jewel"! Thank you for sharing! Thankz
Love Tube Amp Theater. Keep these videos coming. Big Fan.
All your videos rock!!
Nice repair as always. Loved the tube robot!
Great video Terry....You make amp repair fun.
This is what I call a superb tech . Classy work bro ! Enjoy all your videos. Pleasure to watch this fine workmanship .
You are too funny bro!😎 I always enjoy your videos. I build and repair amps full time and still seem to gravitate toward videos made by pros like you for enjoyment before the lights go out. Thank you!
HOORAY for the Ungar SNOZARAMUS iron!
Used to use one in Traffic signal manufacture, and they're invaluable for heating chassis!
The amp sounds great Terry! turned up to 5 is louder than 10 used to be. Thing cranks. Great job, thanks again.
Super cool man. Glad your pleased. It was a great project. CU in 2017. TD
The production values on your videos are great!
Terry, your videos are really great. Cold here in Chicago same as you in Michigan. Looking forward to more amp videos. Peace !
Thank you for this excellent and informative video! Using this video I was able to fault find and repair my 1970s Silverface Champ - thank you!
Super cool man
Hi,Terry enjoyed the video and your work ethics are brilliant!! right up my street keep them vids coming Thanks B.
Tube amp thee-yay-tah !
Sicskull and Beavehurt give it two thumbs way up!
Good stuff, Terry. Keep 'em comin' !
Man, what a great video! And the Intro/Outro was awesome!
Perfect! Just the video I needed! :) Thanks!
Another great save, of a vintage Champ. Long may she make music.
Hi Terry happy belated birthday. Always good to see you working on stuff. A friend gave me an old Epiphone galaxy 10 guitar amp and it had a burned out power transformer. From what I read on the internet this is a common problem with this amp. I fixed and it works good but a fender champ will blow it away and a fender has a 6v6 smaller tube. The Epiphone has a 6L6. I'm thinking of putting a champ circuit in it
Love champs i learn how repair tube amps with mine and your videos🙂
Best intro yet !!
Thanks for posting these videos. You’ve inspired me to troubleshoot my amp. I have a silver face champ that I replaced the filter cap around 10 years ago and the other electrolytic caps and all was good.
Now a few years later when I play through it there is a fuzz sound as the notes die off. Not musical fuzz either.
Subbed tubes and played through a different champ speaker just in case.
So, I need to get to troubleshooting.
Thanks again. All your videos are helpful sir!
Mike, sounds like you might have a "parasitic oscillation". Sometimes caused by bad caps, electrolytics in particular, and perhaps your 10 year old electrolytic cap is failing (they sure don't make them like they used to!). Could also be due to a bad solder connection ( every Fender I've ever worked on had one!), a bad 6v6 cathode bypass cap, or a noisy resistor.
Did you ever figure it out?
Thanks for another great video. I have an old amp. No name on it, but I researched and found its a Orpheum Omega from 1959. It has a 5Y3 that's discolored like that one. I'm gonna check to see if I can find what is causing that. I don't want to lose my power transformer either! It had a lot of noise and I cleaned corrosion on the 12AX7's. I cleaned that and it sounds beautiful! Still gonna check out the reason for the discoloration of the 5Y3. Thanks for the tips!
Good tip about the cathode cap 2-> 25uf. And hey! I have the same scope, 2235A, love it! It seems you use several, and I always enjoy seeing how you use them to quickly find signal issues.
The good ol Beckman
Great little amp to save,,,,wtg,,,, also Terry, nice little bot.
Nice video man they are sweet amps.
Fine Job Sir.. thumbs up.
Nice job
Good job boss... I like your style.
working on a Champ right now. can cap blew out and 12AX7 tube bad. thanks for suggestions on cap changes. waiting on parts
then see if anything else needs replacing. great video!
WOW DLAb AMAZING!!!!!
Terry, thanks for all the vids. You know you done good when people are still commenting 3 years later. It appears that the C-CE20X4 caps are now rated at 65 degrees C instead of 85. Does that matter? Thanks again.
Omg. I just love the tube bot... Where do I get mine. Lol.
Nice, the robot was sad, at first, but he got a tube upgrade, so all is well!!...LOL You didn't mention that on the filter cap can you connected two legs to make a 40 out of the two 20s which then brought it to spec, 40,20,20.
cool, subscribed and rang the bell
Hey Terry would you please provide a list of components and in the case of the filter cap where they can be purchased part number? I have an original champ that’s starting to hum so it’s time to give it some love. Also I saw a video of a guy who installed push-pull switch on the volume control to activate a “bright” circuit and another for a circuit similar to an overdrive. Thoughts thanks for all you do really appreciate your channel.
The Intro, love it!
That's the best D-Lab intro.
About what temperature does your soldering iron need to be to unsolder the tabs on the filter cap? I have a 1974 silverface Champ that I need to do the exact same thing to.
Weller makes a decent soldering iron.
Is that a transmitting tube sitting on the table in front of the audio generator?
Much appreciate the videos.... Do you know where I can get a schematic for a 74 Champ?
So, Terry, I was wondering. Why did you replace the metal p/s filter cap with a look-alike on this repair; but left it in place (but disconnected) on another repair and used discrete caps on the board?
Cost? or Aesthetics?
Thanks
Anyone know what the small disc capacitor is across what looks like pins 5 and 8 of the 6v6? I don't see this in the schematic or the layout for this amp. I have one of these amps and that capacitor is not present. Anyone know?
Love these videos. Really helpful to stay distracted and learning through these stressful days. Thanks DLab!
Love watching your vids but now I would need some help myself too.. Got some 100Hz buzz from my '66 vibro champ with new caps and filter cap, serviced few years ago. The buzz is always there, independent on the knobs position. It dissapear when I remove rectifier or power tube. Oh and the amp plays nice, but that buzz is just too loud. Any idea where to start searching for the problem?
Hi Terry, I am wondering if you always power up for the first time with only the rectifier tube in place? I am building.a 5E3 for my son for Christmas and I am just about ready for the first power up. I use a variac, not as nice as the Temna, but it works. I also use a light bulb current limiter. What are your thoughts on this?
Hello, a current limiter is a great idea. That will protect the power tranny in case of a short.
isn't the secondary voltage a bit high on the PT?
These videos are INCREDIBLY helpful, thank you! 👍 I have a silverface champ that I bought used whose faceplate looks a lot like that. Does anyone know if there's a way to clean off that white corrosion? I can't find any answers, which leads me to believe there is no way. Thanks again 😁
There is no way to clean it, but you can buy a new faceplate, there are some repros for sell in the web
Awesome input from you Mister D-Lab! Love your videos, they are amazing.
I have a question regarding the max capacitance you can attach to an 5Y3 rectifier tube. As I've seen in your videos and other ones, the filter cap is often replaced with 4 x 20µF from CE manufacturing, which would result in 80µF. I read in multiple forums that the capacitance after a 5Y3 shouldn't exceed ~35µF. Can you explain me the thing I don't seem to understand?
Thanks for all your videos and great humour!
Greetings from France
The Champ has 3 x 20uf. So you just use three on the new can cap.
Hi Terry, thanks for this very informative video. I recently purchased a Vibro Champ from 1977 that is still stock. Owner bought it new in 1977 and only used it the first couple of years. Then it was stored. Now I am checking the amp using your video and I found some issues. First I checked the ac voltage from the power transformer and that looks OK (730v AC). Then I checked the DC voltages. Coming from the board to the first filter cap I see over 400v DC when powering up but it goes down very quickly and stabilizes after a couple of minutes on 260v. That is way too low. Checking the 6V6 I see that one red playing and within minutes the heat coming of the 6V6 is worrisome. So if I am correct I should be looking at the cathode cap and resistor. Should I do a full recap job or should I just work my way through the amp and replace when I find a problem? I know that most of the time one problem leads to another, so I might end up replacing all the caps in the end. However I also do not want to destroy the originality of the amp by replacing everything beforehand.
Patrick Roeleveld, the most likely cause of a redplating 6v6 in your Champ (aside from the tube itself) are a bad ( electrically leaky) coupling cap to pin 5 (grid) of the 6v6, or a leaky or shorted bypass cap in parallel across the 6 V6 cathode resistor (from pinn 8 to ground). Just change those two parts! Also examine the cathode resistor itself, measure it if you can, and replace if it looks overheated or doesn't measure the correct value. I can't remember if the champ has a screen resistor feeding voltage to pin four of the 6V6, but if it does, check that one as well, make sure it is on spec and not burned or drifted way off. A gassy or otherwise defective 6v6 tube could also cause the red plating all on its own, but bad caps or resistors are more likely. You did not say what brand of tube it is, but many modern Chinese or Russian tubes cannot handle the voltages found in Fender Champs or Deluxe reverbs. An old RCA or GE tube would probably be still good today unless the amp has had a lot of use or had been run for hours with the tube red-plating.
Just a question....
I love my vibrochamp
Is there an amp that has similar everything.... just 15-22 Watts??
maybe a fender princeton-reverb?
Terry, are you able to obtain most of your replacement caps, resistors and other parts locally, or do you have to order them? You always seem to have exactly what you need.
Hello, Yes, I have piles of parts here. However, when in need I usually buy from CE Dist (AZ) or Tubedepot (TN)
Just curious did you replace components without removing board?
D-lab That capacitor that was originally blown, parallel with the bias resistor, appears to have just been removed from the amp completely. Is there a reason for that, or did you connect one somewhere else? On my '68 Champ, it appears to be a 25uf 25V cap.
Poduck idk, if you figured it out already, but at 9:37 he shows you what he did with it.
Hey Mr. D. Great video! How many watts is that Unger and where can I get one?
That's an Ungar 776 handle. They were the first company to make a modular soldering iron for which you could purchase tips with built-in heaters. I don't know what size heater he has on it, though. Weller still makes the 7760 which is a modern version of the 776 which uses the same heaters. I think the 4033S is the closest modern heater/tip combo to the one he is using.
Nice Job Terry.... I'm interested if the customer approved the mods you did for the better bass response..
Yep, he's good with it.
Oh and PS - could you do a Silver to Blackface conversion video if the opportunity presents itself and if you haven't already. As I said Im still going through your older vids.
charlie wired that SF to BF thing has always befuddled me. I Own a 79 SF Deluxe Reverb, a 77 SF champ and a 64 BF deluxe reverb, and honestly not a ton of tone difference. in fact, the 79 deluxe is more robust than the 64...
Great job Terry..Im sure you are highly requested for service.
Any special flavor you prefer off the vine?
I love Robert Mondavi, cabs. Do you have a unit in need of repair?
@@d-labelectronics had. Heathkit 10-80m receiver and transmitter set from appx 1973 . Gave to ham buddy kd8tbc Lee, it needing recap kit, re string vary cap tuners and alignment. It all worked fine in the late 80's, but collected dust for the last 18 years..I was not going to power up tubes without a clean sheet..I doubt he has even started it.
If you can log into 2m net sunday nights 9pm 146.640 also an echolink if you are out of range..maybe catch him on air as net control. Im sure he would appreciate some help. I also have many old school chums and few of my customers in the music venue that are always seeking a highly talented tech for vintage equipment, maybe in market to purchase a refurbished antique that has guts .
Robert Mondavi eh?
Til the next local radio and electronics swap..
73, kb8qlz
where does one get these tube robots?
as soon as that filter cap goes so does the mojo. Drops 30% in value as well when it looses its old hardware. but whats the alternative if you still want to continue to play it. ?
Hello, Thanks for the comment. The biggest hazard to a leaky cap is the excess load to the power supply/rect tube/loss of current/crappy sound. You are correct, mojo nogo
A completely stock vintage amp, or an amp that works. The choice is yours.
I'd think that you would get more clean volume with the original bypass cap values - the amp goes lower in frequency than needed even with the original values.
D-Lab is correct. The bass will be better but you may or may not notice it.
Hi. What do you use WD-40 for? Uses?
Its the best potentiometer cleaner out there. Cleans, plus revives the old lube in the pot shaft. I have used it for years.
If you can't find or afford the big tower capacitor, could you describe the configuration of discreet capacitors that would equal (or exceed) the performance of the tower cap. I don't care about deviating from conventional circuit appearance... just equivalence and the best possible performance.
I wish you were my dad
I appreciate it man. Checked out your vids, love it!
too much wine lol
I need a fender pro reverb fixed
Be glad to help. Where are you located?
Florida