Recap My Plexi?

Discussion in 'Let's Talk Vintage' started by Trapland, Mar 5, 2019.

  1. ampmadscientist

    ampmadscientist Well-Known Member

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    "...Which is most likely to reduce the ghosting? First power stage right?"

    Ghosting is the result of 2 frequencies that mix together, forming a third frequency.

    A. The original frequency of the guitar note.
    B. The ripple frequency of the power supply.
    Two frequencies combined results in the forming of a third frequency which is the ghost note.

    But replacing capacitors might not solve the problem completely.
     
  2. Trapland

    Trapland Well-Known Member

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    Ya’ll are dredging up a 6 month old thread and just repeating what’s already been said many times.

    1. I never asked ANYONE if they thought I should replace the caps. I don’t care what best practice is, which type of caps are the best or if you think it’s stupid to leave it unserviced. Again I DID NOT ASK IF I SHOULD RECAP MY AMP. I only wanted info about acquiring NOS caps.

    2. If @Bob Barcus didn't run around quoting stuff all over the forum without actually adding anything, this thread would be asleep as it should be.

    3. You all turned it into a “should I recap my amp” thread. I titled it “Recap my plexi?” to ask something specific and clearly many MANY people never even read the first post before slinging crap.

    Have fun.
     
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  3. ampmadscientist

    ampmadscientist Well-Known Member

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    I only wanted info about acquiring NOS caps.

    I'm afraid that any manufacturer who had new caps that old would throw them away.
    Anybody in this industry who wants reliability would never use electrolytic caps that old.

    There is "re-forming" capacitors, but this should not be considered a permanent solution for aged electrolytic caps.

    Unfortunately the only reliable replacement is a new one.
     
  4. Matthews Guitars

    Matthews Guitars Well-Known Member

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    NOS caps would be the worst possible choice. They've been stored without voltage applied to them for decades. Their anodizing on the plates will be mostly gone and they'll probably short out and explode very quickly if you were to just install them and fire up the amp. They're WORSE than caps that have been in regular or even infrequent use for decades.

    You would be money ahead just to shoot your amp with a shotgun right now and call it a day. Yes, putting in NOS caps would be just about that bad. I'm not kidding in the slightest.

    However, I have not been instructed to NOT reveal what I am about to tell you.

    The company that was Daly capacitors has changed hands several times over the years. The company that carries their legacy and has the legal rights to the Daly brand name is a major premium grade capacitor supplier today.

    I have personally had a conference call with their product representatives and development teams. I have told them that I believe there is a decent sized market for authentic new production Daly capacitors for the Marshall refurbishment/restoration market, with other amp companies also being able to use the same capacitors and probably they would be quite willing to do so.

    That team is taking a very SERIOUS look at the notion of restarting the Daly line and making brand new, Daly brand, correct value, cosmetically correct capacitors for us. Of course they'd have current date codes. This would be the best possible answer.

    Pray that it happens. I believe it can. If they played their cards right they could once again be the brand of choice for Marshall and also for every builder of Marshall clones, and of course, for every Marshall amp tech who's worth the price of his roll of solder.
     
  5. anitoli

    anitoli Well-Known Member

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    But shouldn't he replace them? :D
     
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  6. purpleplexi

    purpleplexi Well-Known Member

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    The great beauty of such amps is that they are infinitely repairable. In 200 years' time they may be George Washingtons axe (3 new handles and 4 blades but still the same axe) but with maintenance they will still be doing more or less exactly what they do now.
     
  7. Matthews Guitars

    Matthews Guitars Well-Known Member

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    Provided that parts are still being made. But long before 200 years pass, there will be capacitors available that will basically last forever and the hard part will be finding a way to install such a TINY little capacitor in a 35mm clamp!

    I think the day will come where it's practical to 3D print replica tubes that actually work. The 3D printer would have to be in a vacuum environment, of course.
     
  8. shakti

    shakti Member

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    New production Daly brand caps would be cool, but the important thing is how they sound. Filter capacitors are not made the same and don't sound or feel the same, even with comparable ESR and uF readings. Don't ask me how that happens, but my testing and experience over the years tells me it is so.

    So it would take a little more than just a nice blue film with Daly printed on it over any generic filter cap to convince me to buy.
     
  9. Matthews Guitars

    Matthews Guitars Well-Known Member

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    It wouldn't be generic! The company that owns the rights is one of the best capacitor manufacturers on the planet. Absolutely top notch product.

    I probably shouldn't reveal the company name but nothing keeps you from researching and figuring out who owns the rights to it now. That's how I found the company and got in contact with them.
     
  10. ampmadscientist

    ampmadscientist Well-Known Member

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    I love NOS coupling caps (de-coupling caps) .
    I use new Filter caps. I use some new coupling caps.
    I can't get the sound I want from many new coupling capacitors:
    So I invented a new method of inter-stage coupling that has never been done.

    I use old / used / NOS coupling capacitors to get a sound which I cannot get from new capacitors.
    And many of these old coupling capacitors were intended to work almost indefinitely, not the same as filter capacitors.
    It is very rare for one of these to fail in an audio circuit.
     
  11. Matthews Guitars

    Matthews Guitars Well-Known Member

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    NOS coupling caps are fine. I don't even mind old used ones if they're in good condtion. In a Fender I really like using the dark blue Paktrons. They're very reliable and sound good. It's electrolytic filter caps that should be viewed with a jaundiced eye if they are more than a few years old and haven't been put into service yet.

    A failed coupling cap isn't going to cost you a power transformer.
     

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