How to repair noise Vintage Fender Champ tweed tube guitar amp 1956

Tube amp theater strikes again. Featuring a cool HP-140A analog oscilloscope from the day. The repair went very well. I really enjoy troubleshooting vintage tube amps and Ham radios. Hope this info helps you to diagnose your amplifier issue. TD

[@deepwater2652]

LOL! Reminds me of the old science fiction show that would start with an oscilloscope pattern on the screen and the background voice intoning "Do not adjust your television set - we are in control of it!"

[@billdyke9745]

So, no new components, no hidden problems, just stuff that a sensible eye should spot. Unlike Fender 54 years ago. A good lesson. Thanks.

[@roberthurless4615]

Watching that scope reminded me of the old "Outer Limits" show. I loved that when I was a kid. Great video with some good tips. Thank you Terry

[@MrSomchiman]

Great repair services. I may not know all of this, but I surely learned a lot to taking care of my amp.

[@shana_dmr]

Very nice job!:) I sometimes can't understand customers that insist on keeping things that wear out naturally (like connectors) original. There's a difference between maintaining gear in the museum and actually using it every day. If you sent that amp to Fender for repair years ago they would just use any matching jack connector they had at hand and not search for NOS 20 years old one. Most components (sans things like ultrastable voltage references) aren't aging like wine. If I'm doing repair for myself I'd just use good quality new connectors that are matching mechanically and not spend ten gallons of deoxit to make old crusty 5$ connector work again.

[@sharonlee4773]

Here,here!

[@zing913945]

Very cool ! Thanks for the inspirational video. I have a 1959 5f1 When I found it it was missing the tubes, the pilot lamp and jewel, the fuse and the top to the fuse holder. The inside is pretty darn clean. I just ordered the missing parts. Lucky for me before my brother passed he gave me a variac so I can slowly bring the voltage up and hopefully not blow out the caps. I'm going to give it a try and hopefully not burn the thing up. I haven't worked on an amp since my electronics classes in 1968. But I'm well prepared I got a bottle of wine and a lot of fun memories from the bars and clubs I worked in the early 70s. I hope mine goes as well as yours did! Next on the list is an old magnatone tube amp with a spring reverb that looks a lot like a twin reverb. I know it needs caps because it sounded like a pop corn popper Thanks for the cool video.

[@dwightjt]

Yes I did like the vidio +your goofy and funny But very smart and knowledgeable Good job your the man Terry. Dwight.

[@TheBoss1597]

Great Terry! Always a source for inspiration and great tips! Thanx from Sweden

[@brentstewart59]

Great video and always very informative. Thanks very much Terry for sharing your wealth of knowledge. Cheers my friend

[@MuscleDad420]

Those F&T and Sprague Black Atom caps are recent. Somebody has definitely been in there before. This would also explain why the jack shorting clips were bent out of place.

[@davebolden4355]

just saw your post after posting mine, glad other people are paying attention, kudos on the 420 btw

[@dale1956ties]

I think when he said no one's been in here he was referring to that 5Y3 socket he was chopsticking at the time. Yeah, he should have said so specifically but I'm pretty sure the guy knows those filter caps weren't factory.

[@pumpdumpster]

Well done Terry, thanks for the video. I look forward to the next. :-)

[@bcarr3116]

So the HP-140 has a 8 ohm speaker built in ? Cool! Great idea. See and hear your repair. Beats load resistor on the output which is no sound just sine wave. Wow HP-140 Thanks again.

[@djfrank59]

I always say to younger techs (newbies) to look for the obvious. It will save you hours of troubleshooting time. Bad solder joints/unsoldered joints are not uncommon. There's bound to be a slip or two from a factory worker. Whenever I get in any amplifier where there's a noise complaint, or change in output. I keep a bunch of wooden chopsticks (courtesy of my local Chinese restaurant) on my bench for locating bad connections. Love that old HP scope! The fan is soothing :)

[@d-labelectronics]

Thanks man, I love that old scope too. Back in the day they were very $$$$$

[@SDsailor7]

How many MHZ is the O'scope? its a cool looking scope.I want to buy one so I can learn how to use them it would come in handy.

[@SDsailor7]

I got an Epiphone solid state practice amp model studio acoustic 15c that when I turned it on I had nothing but static noise/white noise like when a tv station goes off air. I remove the back to take a look at the board and found two capacitors leaking black goo that had turned hard, so now I have to remove the caps and clean the mess and install new ones. Any idea what might have caused them to leak? any advice would be appreciated.Not shure when the amp was manufactured but it is not a vintage amp that is for shure.Cheers

[@djfrank59]

Capacitors have a limited life, especially cheaper, modern caps from China. After some years of use, they break down and leak (both physically and electrically) from heat and need to be replaced. Many modern day radial lead capacitors are in a soft aluminum container with an embossed seam on the top. When pressure builds up inside the cap, the seam breaks and they leak. When capacitors become electrically leaky, they basically turn into resistors (high ESR) and can no longer filter any ripple, and must be replaced. If you leave defective capacitors in the circuit (especially the power supply), they can short and take out the power transformer, which becomes quite expensive to replace. Terry can definitely back me up on that one! :)

[@kxmrock]

luv the vid... Amp Class 101 of sorts for Me ... Short & Sweet 8min Vid

[@DennisMurphey]

Just found this old video, Outstanding. I am converting an Eico 147 Signal Tracer into a 5F1 Amp and was happy to you checking out this old baby. The stuff you found and fixed is a testament to the Fender overall design. I an doing point to point but after seeing that eyelet board i wish i had sprung for that board. Great video thank you for all you work. Dennis

[@robhaskell4043]

Nicely done ,Sir. And the red wine is a good touch as well! :-)

[@remley8877]

Very cool amp repair! I may be in the minority, but I would love to see a video of your oscilloscope collection.

[@creightonha8725]

Great video DLab

[@Themaremonstrum]

You're my hero!!! I wish I were you!!!

[@CC-te5zf]

It is possible to have a quiet 5F1. I built a clone from a "Build your own clone" "Champlifier" kit - I followed the instructions to a t, keep it super neat, and made some of Terry's recommendations for cap upgrades and she's very quiet. Now if I can figure out how eliminate the attenuation in our home's electrical circuit when the well pump comes on...

[@bubbalou9267]

Love the videos, very informative. You should loose the red wine and switch to bourbon.

[@classicrocker928]

Hi Terry, appreciate the time spent on providing us these videos. You demonstrated that moving the tubes around created a lot of noise, did you have to do any further repairs to fix that issue and/or did you end up replacing the tubes. Thanks again.

[@luthiervandros]

Damnit, lupe!

[@dryocum]

Great work!

[@SebastianRossi99]

Great Man, Great Amp.

[@ofthetree]

No 25uF bypass cap on the first stage in this fella :-)

[@Judas_Umbrella]

Brilliant vid man

[@grahamjsmith1951]

Is there a video of how you reduce hum in a 5f1 Tweed? Love these videos.

[@halbertking2683]

What about the .022 coupling caps? I would not be surprised if they are leaky.

[@jordan390a]

Looks like someone had already been in there and tried to touch up several of the solder connections....Personally I'd have re-capped the whole thing and save myself the migraine when one of those caps starts to leak or blow....

[@randm7252]

be cool to hear that champ demoed:)

[@raulmontesdeoca7843]

Terri can you make a video on the use of an oscilloscope pertaining to testing amplifiers. Inclusive of settings, connections and signal generator connections?

[@d-labelectronics]

Yes Sir, will do

[@raulmontesdeoca7843]

D-lab Electronics Thank You Professor.

[@kevingriffin8854]

very cool channel. would like to see you do something interesting with a fender champ 12 red knob, as I have one and it's just sitting around, I'm sure it has potential, and there isn't much on the web. cheers!

[@d-labelectronics]

Hello, I have a Fender 12 on the bench right now. Minor repair. 3 bad jacks (broken). 1 bad solder connection on a tube pin. Dirty pots. Tubes were OK. Not much to report. What is the issue with yours?

[@kevingriffin8854]

D-lab Electronics broken plastic input jacks, overly tinny/ trebley sound. poory quality reverb.

[@d-labelectronics]

Only replace with the original Fender type. They are still low quality, but better than the after market type. Then inspect the circuit board for cracked solder connections, especially around the tone pots. Sounds like you may have a bad pot or something defective in the tone circuit.

[@thomthumb4937]

Kevin Griffin I have one also. Love it. Wld like to see a video also. I've replaced the input jacks, speaker, and all tubes. Sounds like a new amp. Wld like to see how to fix the volume and gain issues on channel 2.

[@scottbartlett4853]

Cool video! What speaker manufacturer is #395? They are not listed in my EIA code sheet.

[@Haassan1]

I always enjoy watching D-Lab do his thing, but how am I gonna find a repair-man or woman with equal capabillity in my hometown?

[@74dartman13]

Haassan1 I was just thinking the same thing! Man I wish this guy lived near me...hope I can find someone as qualified and honest as he is near where I live!

[@wsscott72]

Terry-I published this same comment in another video, but then saw this one so am re-publishing it. I hope that's ok. Anyway, I got my first amp in 1959 or 1960, it was a Fender Tweed, and I believe it was either a Champ or a Harvard. I know it only had 1 speaker, and I think it was oval. It was pretty small, and of course basic. I'm thinking of building one and trying to figure out which one I had, and/or which one is the better choice if there's no way to tell now which model I had. Do you have any thoughts to help me on this. Thanks.

[@rciancia]

Nice work Terry. Looks like the electrolytic caps were replaced at one time or another was well. I just finished building a 5F1 Champ myself ( home-brew) and it was also quiet as a mouse. I have the video series on my channel. Question, where did you connect the tone generator ? Looks like the 12AX7 pin 5? correct ? Thanks Ron

[@d-labelectronics]

Hi Ron, Glad you liked the video. Great little amp. I connected the audio generator to the guitar input jack. The O'scope was connected across the speaker terminals

[@jackleg266]

why couldnt the jacks be readjusted?

[@jameswallace5967]

Wine and high voltage are a great combination! Lol.

[@thesuccessfulbarber]

Is it possible to dremel the old input plug with a wire wheel?

[@SMITHII_]

What are your thoughts on the heater wiring? This one uses the original wiring scheme with one side of the 6.3 line connected to ground, and the other side going to the 2 tubes. Is this more noisy?

[@XxdartvaderxX]

i had a carvin belair that this thing did the same thing... lol you could hit the amp and then it would start working one of the resistors broke off and i remember my dad trying to fix it we didnt know how to solder right... oh boy it was such an easy fix hahahahaha

[@grahamjsmith1951]

❤

[@BatesAutomotive]

Also need a tube for a 1961 champ amp mine is missing the center tube, do u have or know where I could get one

[@flockoglock]

Excellent video. Do you have, or know where I can find, a video on where to connect an O Scope for testing and how NOT to blow it up. Thanks so much.

[@d-labelectronics]

Hello, I do some some o'scope connection points in my videos, however will produce one going stage by stage. I will make sure to keep it straight forward. Good idea. I appreciate it. TD

[@flockoglock]

+D-lab Electronics awesome, I look forward to it. Thank you for all of your excellent videos.

[@davebolden4355]

i would hope that the fact that there are sprague atom electrolytics in the chassis that there would be a major red flag that indeed there was in fact a tech in there, perhaps within the last 10 years

[@d-labelectronics]

I agree man, my reference to repair history was just the wiring. Yes, it is obvious that some updates had been performed

[@davebolden4355]

love the vids man, keep up on the vintage guitar stuff.

[@aokisounds2432]

How is the best way to utilize both 8 and 4 ohm taps on a new O.T. for a tweed type build ?

[@holmes1978]

Could you Please tell me the brand of the speaker ! Today's reissues are Weber what was the Fender Champ 57 ?

[@DeadKoby]

Find the obvious is the best advice that could ever be given.... that, and LEARN to read a schematic.

[@TimmyP1955]

Those Astron caps have a reputation for leaking - were they checked? Is it normal for a tweed Champ to clip so asymmetrically ?

[@d-labelectronics]

This was not a complete rebuild. The owner just wanted the transformer and to get it going as quick/cheap as possible. Just follow orders here

[@umajunkcollector]

gadzooks Tman, how did that get past quality control? Don

[@d-labelectronics]

Yes, it is surprising that this issue did not surface until now.

[@SDsailor7]

You are doing a great service keeping these old classic amps alive.Cheers

[@A.WebbAndFriends]

I need your HELP - I have a vintage Crate Palomino V16. I haven’t played it in a while and it worked and sounded great before putting it away. I just played it today and it has a HUM that wasn’t there before. I heard that in tube amps IF it’s a low-level pitch 60 cycle hum it’s probably a bad tube, BUT IF it’s a high-level pitch 120 cycle hum it’s probably a capacitor that needs replacing. I took out my guitar tuner and it shows the hum to be about an “A#”, and on another Audio scale it says it’s a 120 Hz pitch MINUS 49 cents ??? What the what ?? The Hum does Not respond to the volume control - does that info help also ?? I do own a multi-volt Meter - How do I locate and test the capacitor if it’s bad or not? Awaiting your reply, and Thanks In Advance - I REALLY NEED HELP WITH THIS.

[@d-labelectronics]

Hello, best thing to do is inspect the filter caps. See if there is oozing from the positive lead. Check for strange bulging. If these are the original caps, just replace them. Make sure to bleed off the high voltage before changing the caps. Verify the power supply is dead with a DC volt meter. The caps can be obtained at the Tubedepot.com. Good luck! Be careful. TD

[@A.WebbAndFriends]

Thanks for taking the time to reply, much appreciate the suggestions too. Will do - AW

[@fretmasteran]

I have that amp and when I had the caps replaced there was an extra cap installed across the last resistor to the right of the chassis . Could that be the source of noise?

[@d-labelectronics]

I believe that would be a preamp cathode cap, usually not a source of noise. Check the tube sockets for wear & corrosion.

[@fretmasteran]

I did not see that 33 Micro ferret 450 V capacitor on your video on your amp could that be why it's quieter than mine?

[@johnsimms3957]

So Leo forgot to put some solder on that one place?

[@d-labelectronics]

Yep, Probably got missed during a coffee break. Thats why we use robots now!

[@GaRbAllZ]

Can you imagine how many times that poor Champ got slapped because of the wire not getting soldered? LOL

[@6150982]

Is anyone else a little surprised with the installation of new jacks rather than refurbishment of the old? The contacts surely could have been burnished and the other issues resolved without removing original, visible, salvageable parts.

[@d-labelectronics]

The contact surfaces were corroded beyond repair. The customer requested new switchcraft jacks. Remember, I am doing these repairs for customers. Either way, I would change them.

[@6150982]

Thanks for the reply. - Derek

[@danroscigno187]

I guess using the original rusty nuts would hide some of the newness.

[@shekador]

It's been proven that the mud dauber was critical for achieving the classic Fender tone, it was purposely omitted from schematics to fool copycats

[@jaysorensenIBEW]

The mud dauber's nest also kept the amp alive by damping the cabinet from vibration and keeping that unsoldered 5Y3 alive lol

[@BatesAutomotive]

Does anyone know a good way to clean one of these? I have a beautiful example of one but it's just dirty on outside, please help

[@davekeating.]

Nylon brush and lukewarm soapy water?

[@Tonetwisters]

Old jacks are pretty much just trouble ... they won't make the sound better in any way just because they are old!

[@wsscott72]

Terry-I published this same comment in another video, but then saw this one so am re-publishing it. I hope that's ok. Anyway, I got my first amp in 1959 or 1960, it was a Fender Tweed, and I believe it was either a Champ or a Harvard. I know it only had 1 speaker, and I think it was oval. It was pretty small, and of course basic. I'm thinking of building one and trying to figure out which one I had, and/or which one is the better choice if there's no way to tell now which model I had. Do you have any thoughts to help me on this. Thanks.

[@wsscott72]

Terry-I published this same comment in another video, but then saw this one so am re-publishing it. I hope that's ok. Anyway, I got my first amp in 1959 or 1960, it was a Fender Tweed, and I believe it was either a Champ or a Harvard. I know it only had 1 speaker, and I think it was oval. It was pretty small, and of course basic. I'm thinking of building one and trying to figure out which one I had, and/or which one is the better choice if there's no way to tell now which model I had. Do you have any thoughts to help me on this. Thanks.

[@JobyP]

That’s an easy one. The Harvard has a Volume & a Tone so you Must have had a champ. The 5F1 Champ is pretty much the most basic Fender amp. And I believe that’s what the one in this video is. That would be the one to build.