Please help, 8.2k 2w Iskra.

Discussion in 'Amplified Parts' started by junk notes, Jul 20, 2019.

  1. junk notes

    junk notes Active Member

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    Hello, I have been trying to finish a Plexi replica build for some time now. I have most everything for the build and have been looking for an 8.2k 2w Iskra that has eluded my radar.
    (I have an 8.2k 2w Piher in that position currently.)
    Thank You for your help with my issue. I appreciate this, greatly!
     
    Nik Henville likes this.
  2. Nik Henville

    Nik Henville Well-Known Member

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    Are you going for sonic differences or period correctness ???
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  3. junk notes

    junk notes Active Member

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    I do have the 1w, but need the 2 watt to change out.
     
  4. ampmadscientist

    ampmadscientist Well-Known Member

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    Start the reactor. free Mars!
    What do you need a 2W for anyway?
     
  5. Adieu

    Adieu Well-Known Member

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    Old Soviet resistors are highly sought-after valuables now????
     
  6. neikeel

    neikeel Well-Known Member

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    If it is for the B+ dropper between screens and PI then it should be a 1W, in series with 10k, 1W.
     
  7. junk notes

    junk notes Active Member

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    Thank you all for the feedback, I really appreciate it. :)
    More of the "period correctness" as mentioned (...and the China hats will look great too!;-)
    Yes, I would like to know Marshall's correct value as it was for the '68 1959's/1992's and not what just "works" in that position.
    I see 2 watts being used in that particular position in most schems, which I assume deals with voltage handling.
    Learning here as I go along, I also see metal film substituted there, assuming that it is used there because mf tend to be more stable to the cc or cf resistors.
     
  8. ampmadscientist

    ampmadscientist Well-Known Member

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    Start the reactor. free Mars!
    OK I found you some 8.2K 2 watt Iskra resistors:
    https://www.ebay.com/itm/ISKRA-8-2K...hash=item1a567f030d:m:mNtLempt5AADRkRPIhh_FwA
    Only $15 each, enjoy.

    Only $7.50 each
    Your lucky day!
    https://www.ebay.com/itm/1-RARE-8K2...350629?hash=item1c6210c5a5:g:F1UAAOSwQJhUk1Bu
    Oops, that's 1 watt.
     
    Last edited: Jul 27, 2019
  9. fifteenohms

    fifteenohms Well-Known Member

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    Are they Heinz or French's...
     
  10. neikeel

    neikeel Well-Known Member

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    The original series droppers (some 10k cc, some Piher and some Iskra 10k or 8k2) all 1 watt rating. They are relatively low resistance so despite seeing 450v or so they don't dissipate that much heat (they are not working that hard).

    You would generally use Metal oxide (flame proof) resistors in this position in a new build for reliablity, safety etc.
    Using a Metal film in this postition is unusual, at least by design. I generally would not use carbon comps unless in an early restoration for accuracy.
     
  11. Matthews Guitars

    Matthews Guitars Active Member

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    You're building a REPLICA. There isn't any slightest need for you to have to go to the extra effort and expense to obtain "restoration correct grade" parts for an amp that will never be the authentic item. In fact it'd be better for those who are restoring authentic amps if you didn't reduce the supply of those authentic restoration grade parts any.

    You should certainly get parts that sound right but you don't have to seek out a 1968 vintage Iskra resistor to do it.

    I would never think to load up a replica I built with restoration grade original parts. I would much rather use Sozo caps instead of mustards. They sound the same.
     
  12. john hammond

    john hammond Well-Known Member

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    - you're right - unless he wants it to look as close to and perhaps sound like an original

    - 99 percent of mustard caps available today are counterfeit, for all I know, sozo are the ones making them ( someone is, believe me and it aint philips)

    If he can find actual genuine NOS mustards made by philips and a close enough output transformer ( they are out there ), his replica will be indistinguishable from an original.

    I'd say a it's a damn noble quest.

    It's an art building a close replica sonically.

    A cosmetic one filled with budget or/ non proper sounding iron and counterfeit mustard caps? - childs play.
     
  13. Matthews Guitars

    Matthews Guitars Active Member

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    Maybe we have what could be called a difference of ethics. Building copies of Marshalls that are so exact that they could be considered to be real Marshall products that came from the Marshall factory is legally and ethically wrong. It's fine to use the same circuits and similar cosmetics but there is a point at which a copy becomes a forgery. That point is where a non-expert would be unable to tell the difference between the two. No new built project amp should ever carry a Marshall badge on it. Or be so identical that adding a Marshall badge would lead people to believe it IS a genuine article.

    On the other end of the instrument cable, I'm no fan of people who make forgeries of Gibson Les Pauls, either. You can make it exact in every detail but the headstock logo should say ANYTHING on it other than Gibson.

    I have a lot of respect for PRS guitars. I have the capability of building PRS replicas that are so exact that they could be mistaken for PRS factory made instruments. I won't do it. I make changes to the body shapes and I have my own ways of executing certain details that keep them from being replicas by any definition. I pay homage to the PRS aesthetics, and in spades, but I won't cross the counterfeit/forgery line.
     
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  14. john hammond

    john hammond Well-Known Member

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    the thought of putting a badge or a name on any amp i build that isn't my name has honestly never entered my head.
    what usually happens is i put no name at all on them, i just play them.
    the thought of making amps that sound exactly like a tasty 68 or 69 plexi, now that's something that i do enjoy thinking about, and doing.
    to me aesthetics has very low to zero value, i just want the sound, and I admire and usually support anybody building an amp, cosmetic clone or not.
     
    Nik Henville likes this.

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