Vintage Fender Harvard Tube 6V6 Guitar amp repair transformer fix by D-lab

Тәжірибелік нұсқаулар және стиль

Hot off the bench. This amp arrived in pieces. Output tranny blasted/gone. Resistors blown up! Needed attention. A friend brought it to me from Bay city, MI. I was lucky enough to have a original type Fender transformer on hand. So, watch and get some free how to tips.

Пікірлер: 74

  • @UncleDoug
    @UncleDoug8 жыл бұрын

    Rusty and I really enjoyed the video, Terry: Excellent pace, clear narration, and a nice conclusion.....much like a good novel. We give it two thumbs and two paws up. Thanks so much for posting it. Now we're off to check out more of your videos :)

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +Uncle Doug Thank you sir. I am honored to have your faith in me

  • @UncleDoug

    @UncleDoug

    8 жыл бұрын

    You're welcome, Terry. Your videos are excellent.

  • @daveogarf
    @daveogarf5 жыл бұрын

    YAYYY! D-Lab Terry and Uncle Doug - ON ONE VLOG! It's gonna' be a Great day!

  • @Shaft-Industries
    @Shaft-Industries Жыл бұрын

    Funny that you mentioned Allen-Bradley. My mother is retired from there as is my Dad and Grandpa. My mother worked in the resistor department back in the late 60's to early 70's. She went to potentiometers after that. Love your videos. Learning a lot.

  • @fenixasin
    @fenixasin4 жыл бұрын

    Finally a tech that knows his stuff with tube amps

  • @Tonetwisters
    @Tonetwisters2 жыл бұрын

    Wow. The Lord was smiling on you, Terry, with that OT! And that 470 ohm resistor, as well!

  • @jonathansmith2710
    @jonathansmith27106 жыл бұрын

    Nice work. I have Fender Harvard H-00416, Date FH which is August, 1956, built just two months after the one in video. Mine is in excellent cosmetic condition with tweed that looks nearly new, probably because it has an original brown canvas cover to protect it and it sat in a dark closet unused for years. Work done: Replaced bias cap, cathode bypass cap & 3 filter caps (all Astron Minimites); Cord replaced with 3-prong; Disabled death cap; Replaced the rectifier, leaving the original bypassed selenium in place; 2 new 6V6 power tubes, and; Rotated speaker 180 degrees to start gravity working it in the opposite direction for the next 60 years. I saved all the original parts in case a collector wanted to restore it to original, but I prefer to keep these old amps playing well. Fortunately, the signal caps tested well so the originals continue to impart their vintage tone. Anyway, good to another one brought back to life.

  • @PleksiHeddamo
    @PleksiHeddamo3 жыл бұрын

    Uncle Doug and Terry, you guys are my favorite valve amp Gurus! Best wishes from the land down under!

  • @silasfatchett5693
    @silasfatchett56937 жыл бұрын

    Valuable information. Clear, concise and to the point. Not always the case on KZread videos. Thank you, Sir!

  • @74dartman13
    @74dartman136 жыл бұрын

    I think it's great how you take the precautions. Better safe than sorry! Great work!

  • @skev27
    @skev279 жыл бұрын

    Nice to see this old amp bring up to life! It makes me think that i have to find a variac or i will have problem one of these days ! Thanks for sharing

  • @mandolinnana
    @mandolinnana7 жыл бұрын

    Thanks for the informative videos. I like the way you show what you are doing and not just saying what you are doing. Thanks and keep up the excellent work.

  • @Themaremonstrum
    @Themaremonstrum5 жыл бұрын

    You ARE a genius!!! I wish I lived around your area to get my vintage Sinmarc amp repaired by you!!

  • @johncunningham5435
    @johncunningham54358 жыл бұрын

    Once again Terry; excellent approach to making sure the old girl will run without a hitch.

  • @stephenquail3168
    @stephenquail31687 жыл бұрын

    Another goodie .I just love close ups and detailed info.very nice.

  • @ianbanhamamprepair9457
    @ianbanhamamprepair94577 жыл бұрын

    Hi D-Lab, thanks for your great vids , I watch all your amp repairs and I am constantly learning from them. Thank you.

  • @d-labelectronics

    @d-labelectronics

    7 жыл бұрын

    Thanks man, I appreciate it

  • @74dartman13

    @74dartman13

    6 жыл бұрын

    Ian Banham I 2nd that comment! Since discovering D-Lab videos, I've been watching as many as I can and learn something from every one!

  • @barbmelle3136
    @barbmelle31366 жыл бұрын

    old school industrial electricians used to "adjust" the resistance of carbon resistors by grinding away some of the carbon. There were actually boards made with carbon pads on them that the calibration procedure was to saw a slot partially across the carbon pad.

  • @joelaughlin5532
    @joelaughlin55324 жыл бұрын

    Always entertaining n veeerrryyy informative! D lab rocks! Keep it up!

  • @bartmeijer1059
    @bartmeijer10598 жыл бұрын

    Hoi Terry, Nice video's! You making tube tech very clear to many people! I'm a also a repair man, but i do not have so much experiance on tube amps. You're video's clear a much questions. Thanks for that, i' m follow you, and watch all your video's! Grz here from Holland, Bart

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    Cool deal man. Glad I can be of assistance. More videos will be posted soon. Lots of projects, limited time

  • @Bbendfender
    @Bbendfender8 жыл бұрын

    First day to watch your videos. They are very helpful for someone like me who plays Fender tube amps.

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +Bbendfender Glad to help out. I am located in Battle Creek, MI, the corn flake capital, cereal city, etc

  • @kd5ozy
    @kd5ozy9 жыл бұрын

    good job! I built one of those from scratch. I love the old Fenders!

  • @d-labelectronics

    @d-labelectronics

    9 жыл бұрын

    James skippinhopper Hello, Yes, this is a nice straight forward design. I enjoyed the repair

  • @ferraridinoman
    @ferraridinoman4 жыл бұрын

    Very nice Young Dave, but come on! your NO Emi!! ha ha!

  • @bmwm3cs
    @bmwm3cs9 жыл бұрын

    Thanks for posting.....love your vids

  • @d-labelectronics

    @d-labelectronics

    9 жыл бұрын

    bmwm3cs Roger that Sir, will keep them coming

  • @moodyga40
    @moodyga408 жыл бұрын

    tues circuits are so easy and fun love building tube amps

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +ian “valve doctor” forster I agree, it is a nice past time of mine. And yes, it normally doesnt pay. However, the end result makes it well worth the effort.

  • @CurranLong
    @CurranLong7 жыл бұрын

    No guitar through the amp?! haha, thanks great video

  • @dwightjt
    @dwightjt3 жыл бұрын

    I like you terry U MAKE A LOT OF SENCE

  • @MrLamar-vs6el
    @MrLamar-vs6el9 жыл бұрын

    you're a great American

  • @anthonyreo5075
    @anthonyreo50758 жыл бұрын

    This was the first video of yours that I was fortunate enough to have come across. I enjoyed observing as you restored that chassis. I have one question. I was surprised that you did not immediately replace that selenium rectifier, it has surely outlived it's life expectancy. Why did you not automatically update it with a properly rated solid state diode? As an old service tech new to guitar amplifiers I'll watch all your related videos! This old dog is full of new tricks!

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +Anthony Reo Hello, Yes, you are correct. I would have, however the owner wanted to simply replace the incorrect output transformer. He ended up selling the amp a few weeks later for a nice profit.

  • @billmiller119
    @billmiller1196 жыл бұрын

    D- LAB ON THE VIDEO THAT 4 THOUSAND 700 OHM RESISTOR LOOKED LIKE IT HAD BEEN PARTLY GROUND AWAY IS IT POSSIBLE SOME ONE TRIED TO MAKE THE VALUE 470 OHMS I NEVER EVEN THOUGHT OF THAT UNTILL I SAW THE WAY THAT LOOKED ! ....////

  • @sarapaylor8065
    @sarapaylor80658 жыл бұрын

    i'm with bob barcus. One chord and the rest will come easy!

  • @is1amizationbyimmigration262
    @is1amizationbyimmigration2627 жыл бұрын

    Klingons: Yes the Praxis resistor IS blown! However we Do NOT require your assistance at this time; maintain treaty boundaries, stay OUT of the Neutral Zone...End Transmission...

  • @shapoolbaghdad7280
    @shapoolbaghdad72806 жыл бұрын

    sir do you have any idea about mercury in radio please help with regards

  • @w7hrcgreg
    @w7hrcgreg7 жыл бұрын

    Hey there, another Great video! Just a quick question. I have had a number problems with old selenium rectifiers, is there a reason for not changing them in this unit? Keep up the videos...

  • @timwarneka
    @timwarneka7 жыл бұрын

    Great video. Forgive this basic question: on some forums I read, people insist that the selenium rectifier must be replaced. Or the world will end. You left it as is. I'd be grateful to hear your thinking on the replace of these rectifiers. Thanks!

  • @silasfatchett5693

    @silasfatchett5693

    7 жыл бұрын

    He probably works on the principle of 'if it ain't broke, don't fix it'.

  • @activeeq
    @activeeq8 жыл бұрын

    Great video thank you! What became of that disconnected cap?

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +activeeq Oops, Yes I did fix the disconnected lead. It was the preamp cathode cap. Forgot to follow up.

  • @davekeating.

    @davekeating.

    7 жыл бұрын

    That is the bypass capacitor for the input/preamp tube cathode resistor. I suspect it was deliberately cut. It was an old trick some players, especially harmonica players, used to tone down an amp’s gain. Helped reduced feedback and increase compression. That ol’ Harvard would be one hell of a harp amp!

  • @joshua0226
    @joshua02264 жыл бұрын

    Could I send my champ clone to you? It blew a fuse recently after I assembled it

  • @rpbale
    @rpbale7 жыл бұрын

    Thanks for sharing. If you had higher plate current, what would you have looked for next. The big caps were replaced already. If the power transformer had been leaking would that cause low secondary voltage but high primary current flow? I ask because I have a Musicman HD130 410 that draws about 1.5-2 amps when the standby is off. Not sure what's causing it. Tubes and caps have been changed.

  • @d-labelectronics

    @d-labelectronics

    7 жыл бұрын

    Hello, I have seen that issue on older amps. It is a defective power transformer. 1 way to tell is to perform a continuity check from the primary to secondary's. See if you have a current path. If so, you will need to obtain a replacement. TD

  • @rpbale

    @rpbale

    7 жыл бұрын

    D-lab Electronics I'll check that. It did fail a ring test while still in circuit. You've given me a good reason to disconnect it.

  • @rpbale

    @rpbale

    7 жыл бұрын

    Turns out there is no continuity between the pri and sec windings. This trans has 6 leads for 3 separate outputs on the sec and the pri has 4 leads for a single input with 2 additional taps. The additional taps are for high and low power and an extra for a neon light. Because there were the expected low ohms between the primary wires it makes me think there could be a short out on the board. I forgot to mention that the short only or high current only occurs once taken out of standby. The 6.3VAC lines are okay. The plates are only receiving 568v while the spec is 725v. Same with tubes out. Testing the current while lifting the red sec is the same as using the standby switch. It's probably right in front of me.

  • @contrabandjoe7974
    @contrabandjoe79748 жыл бұрын

    Hello Terry- just found your videos and will subscribe. question- I've got several silver face fenders from the 70's (Deluxe Reverb, Twin, Super Reverb and a champ) all of them have RCA power tubes (pre amp tubes all replaced) when it comes time to replace them, do you suggest spending the money to get NOS RCA Tubes? worth the money for the tone? thoughts?

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +ContraBand Joe Hey man, There is some magic to the old vintage tubes, however, they can also be microphonic nightmares. I normally buy a nice set of reissue Tung-Sols from the Tube depot. Can't go wrong there.

  • @roberthurless4615
    @roberthurless46158 жыл бұрын

    HI Terry, I see you have Textronix 2235 scope. I have my eye on a 2225 on Ebay for $250.00 including two probes. It is 50Mhz not 100Mhz. Is that enough bandwidth for most tube ans solid state amps? I just found your channel and I find it very helpful. I will be watching more vids in days to come.

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +Robert Hurless Hello, Yes, the Tek's are great scopes. Sure are a lot cheaper now. $250.00 would be top dollar for one. I would hope it has the original manuals for that cost. You could get away with a 10MHZ scope for all audio work. I normally recommend a general dual trace Leader or Iwatsu for this type work. Glad you like the videos. I plan to do more when time allows. TD

  • @JolicoeurAbear
    @JolicoeurAbear3 жыл бұрын

    what is the name of the output transformer that you put in? can it be the same as for a 5e3?

  • @kornami8678
    @kornami86785 жыл бұрын

    I'll bet you that 4.7K resistor was not blown up but was intentionally mechanically ground down to make a 470 ohm resistor. Did you ever measure it?

  • @albertreigle9195
    @albertreigle91956 жыл бұрын

    What does Dumble do to make an amp so much better?

  • @d-labelectronics

    @d-labelectronics

    6 жыл бұрын

    Magic dust. I would assume, high quality transformers. Have never been in one to see the tricks. I hear they are great machines.

  • @georgeswanson9483
    @georgeswanson94836 жыл бұрын

    Shouldn't you get rid of the selenium rectifier? They don't age well from what I hear.

  • @silasfatchett5693

    @silasfatchett5693

    6 жыл бұрын

    If it ain't broke, don't fix it?

  • @davidreid6957
    @davidreid69578 жыл бұрын

    are you available for council? it is hard to find a good amp man out in the country. WNC western mountains

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    Hello David. I am always glad to help with vintage electronics questions. I do have a day job, so sometimes I am a bit slow to answer. Let me know what you need. TD

  • @beeastman1235
    @beeastman12358 жыл бұрын

    How do I remove/replace faceplate on gender twin reverb?

  • @martinreid1740
    @martinreid17407 жыл бұрын

    was that so called death capacitor that had been cut at the start of your video ?

  • @silasfatchett5693

    @silasfatchett5693

    6 жыл бұрын

    That was the cathode bypass cap for the first tube. Probably cut to decrease the gain of the amp. I believe it's a common mod for harmonica players.

  • @BenPrevo
    @BenPrevo8 жыл бұрын

    FF = june 1956

  • @gobigrey9352
    @gobigrey93524 жыл бұрын

    I reckon that background music makin me nervous. Mmm hmm.

  • @tylerjones3989
    @tylerjones39898 жыл бұрын

    Its basically a 5e3 Right?

  • @d-labelectronics

    @d-labelectronics

    8 жыл бұрын

    +Tyler Jones Yep, sure is. Crazy how much they sell for

  • @bobbarcus8310
    @bobbarcus83108 жыл бұрын

    You should learn at least one guitar chord Emaj thanks love the vids

  • @internetnow5243
    @internetnow52435 жыл бұрын

    WHY DON'T THE CHINESE CLONE THESE - THEY DON'T LOOK HARD TO MAKE.

  • @JolicoeurAbear
    @JolicoeurAbear3 жыл бұрын

    what is the name of the output transformer that you put in? can it be the same as for a 5e3?

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