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Restoring an old Twin reverb

Discussion in 'Amp Tech Center' started by Blue Bill, Oct 25, 2020.

  1. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

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    That reverb transformer is 9th week of 1966. The PT is 16th week of 1966.
     
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  2. King Fan

    King Fan Poster Extraordinaire Ad Free Member

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    Trade-offs. Resale 'profit' vs. resale ease vs. other considerations... I see you're in Maine. If you're in Portland, can sell it in Boston, or want to ship it wherever, you could certainly save yourself the trouble and expense of recapping it. Some folks will *definitely* buy it as all original -- collectors, and competent let-me-fix-it home techs, and guys who use their own pro techs, and the Skip Simmons crowd who want to leave it old. Some of them will pay more for all original -- some will talk you down as they or their tech will need to do all the work. In any case, if you aren't sure your repairs would work and look top drawer, that's a strong option.

    If you're in Presque Isle, or wanted to play it yourself and flirt with keeping it, then also show it to local buyers over time who wanted to plug it in and try it, you could certainly sell it as 'recent full e-cap job and 3-prong cord' -- especially if you'd enjoy doing the work yourself. But still, you'd want to make sure your work was logical, needed, and solid in components, soldering, function, and appearance.

    What *not* to do is pay a tech full price for an overhaul and then try to recoup that cost on a sale.
     
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  3. Phrygian77

    Phrygian77 Friend of Leo's Gold Supporter

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    Some folks seem to have the attitude of not trusting anyone else work, and they are going to take it to a tech anyway who they trust. Kind of irks me since I put A LOT of pride into what I do, and I use the best components.
     
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  4. ThermionicScott

    ThermionicScott Poster Extraordinaire

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    Didn't see this addressed yet. The 1500-ohm resistors are for the grids and won't affect the screen voltages, to say nothing of "balancing" them. Screen current is very low at idle and low power, so high-precision/matched screen resistors would be a waste of time, too. Their main job is to quell oscillation.

    Negative feedback mods are something to consider if you decide you're going to keep the amp, but not if you might sell it.
     
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  5. 24 track

    24 track Doctor of Teleocity Ad Free Member

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    if one contacts him to let him know the intent of the repair , he builds a custom kit for you , caps, resisters etc and like you he knows his stuff very well , ebay has the stock kits his site is a little comprehensive. Kits come with full instructions .
     
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  6. Ten Over

    Ten Over Tele-Holic

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    I have documentation for 1965, 1966, and 1967 Fenders that have those GE caps in them. A 1965 Bandmaster had an EIA/Date Code of 1886513 and a 1967 Bassman had an EIA/Date Code of 1886626. A 1966 Pro Reverb had a code 1886540 and another number: 43F7886AA1. I believe these are the exact same numbers as Blue Bill has.
     
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  7. Ten Over

    Ten Over Tele-Holic

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    No. That is very typical. Same stuff is on your reverb transformer.
     
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  8. Blue Bill

    Blue Bill Poster Extraordinaire Ad Free Member

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    Thanks King Fan, I'm thinking I wouldn't get more than $800 or so, if it is not ready to play. I do enjoy doing the work myself and consider myself a pro-level solderer, having done many thousands of solder joints.


    I'm with you Phryg, I trust a tech that has earned a good rep. If people don't trust my work, they are free to have it evaluated by someone they trust, I don't mind.


    I'm seriously leaning toward keeping the amp and making it road-ready, and forgetting about what a prospective buyer will think. Within sensible limits, of course. Plus I try to only do things that are reversible, where factory stock has some value..
     
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  9. Blue Bill

    Blue Bill Poster Extraordinaire Ad Free Member

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    Uh-oh, I just spotted a leakage turd on one of the filter caps, that answers that question.

    123_0502.JPG
    Chassis shot: 123_0503.JPG

    Reverb tranny: those are definitely not factory mounting screws. Come to think of it, I'm remembering: this transformer was missing when I got the amp, I installed this one.
    123_0504.JPG
     
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  10. Blue Bill

    Blue Bill Poster Extraordinaire Ad Free Member

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    I'll contact him, thanks for the recommendation.


    Thanks 10/ I love the shiny copper wrappers, too.


    Great news.
     
  11. Blue Bill

    Blue Bill Poster Extraordinaire Ad Free Member

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    LOL, I was just on ebay, messaging fenderjunkie73. One of the knobs on the amp is missing the little silver insert, so I thought I might find one listed. Wow, people want $25-30 for an old knob. One guy is selling a "set" of 9 knobs, for $400!! :eek: Plus $15 shipping. :lol:

    I think it looks just fine the way it is.

    I'm nearing total commitment to forgetting about selling the amp, and just having fun with some minor hot-rodding. What do people think about a bright red power cord? I bought a 12/3 extension cord from MM, and made it into the Ultimate cord, with some hospital-grade receptacles I had lying around. The quality is really nice. And it's red.

    HD-CORD-02-3M.jpg DSCF0037.JPG
     
    Last edited: Oct 26, 2020
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  12. ThermionicScott

    ThermionicScott Poster Extraordinaire

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    If this were my amp, I'd do the same. Keep it healthy, with no surprises for the next guy, if there is one. :cool:
     
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  13. charriman

    charriman TDPRI Member

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    As did my 66 Bassman.
     
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  14. avspecialist

    avspecialist Tele-Meister

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    I only said that because the GE ones are the same ones that came out of my 67 Super Reverb, that was repaired in 70/71. I didn’t notice any date codes looking at the photos.
     
  15. SoK66

    SoK66 Tele-Afflicted

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    A cursory glance at your photos says the amp is virtually untouched. Were it mine I'd change out the power cord with a 3 pronger, bypass the accessory outlet completely for safety, replace all the electrolytics, replace the dropping resistors in the doghouse while you're doing the filters, replace the cathode & plate resistors to correct preamp tube bias, plate voltage and eliminate carbon comp hiss. Test the ceramic caps for leakage, replace as needed. Enjoy the Amp!
     
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  16. soundcloset

    soundcloset TDPRI Member

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    Meanwhile you could get $700, $800 for the Datsun today...
     
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  17. Crunchmeister1435

    Crunchmeister1435 TDPRI Member

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    Are those resistor leads hanging out from under the orange caps? I'd surely slip those loose before they touch the chassis.
     
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  18. Recce

    Recce Friend of Leo's Silver Supporter

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    I would not put a red chord on the amp but if you like it that is personal choice. I don’t know of anywhere red would look good.
     
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  19. franblanc

    franblanc TDPRI Member

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    Watch Uncle Doug on You Tube he has fabulous instructional videos on how to restore vintage amplifiers of this era. Better still, send him the amp and let him restore it. If you haven't restored an amp before then don't start with something this valuable. Brad the Guitologist is good as well. He would recommend changing those brown disc capactors.
     
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  20. tubegeek

    tubegeek Friend of Leo's

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    MUCH faster than a black or grey cord.
     
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