SDA 1

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  • Gardenstater
    Gardenstater Posts: 4,187
    edited April 2022
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    pitdogg2 wrote: »
    pitdogg2 wrote: »
    I made a mistake. it was the .5uf not 5.8. too early to talk tech evidently this a.m. I remember the cap just didn't remember the value.

    If I think about it after work I'll take a picture of my XO to help relive your anxiety :D

    I hear that. What about the 3 inductors that yours "never had"?

    It's more like Engineer's OCD than anxiety :D

    Read step 4 Z-network that is what I was referring to. Mine did not come with that network. I'm assuming that was the 3rd big coil you were referring to. YES mine has the normal inductors on the board.

    OK gotcha. That's a wrap then lol. No, the "Z-Network" (as Polk called it....probably short for Zobel) was apparently a 55 uF cap in series with two paralleled 7.5 Ohm resistors. So it was basically a cap and resistance in series. :)@DarqueKnight please disregard my attn: above.

    Not trying to be a fact checker (uggh). It all started with my curiosity and now I *think* we are back full circle to that forum quote actually *is* in error because there was never a reduction of inductors from 3 to 2. Phew. Sorry everyone.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • BlueBirdMusic
    BlueBirdMusic Posts: 2,081
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    @pitdogg2 said:
    The SDA1a had a small round binding post cup and no fuses.


    Picture of terminal cup on my 1As in storage.
    7b285ly98j0y.png
    "Sometimes you have to look to the past to understand where you are going in the future"


    Harry / Marietta GA
  • Angio II
    Angio II Posts: 1
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    I have exactly the same ones and bought them in San Francisco back in 1985 asd SDA1.
    They still deliver a great sound without having had to replace anything.
    People here in France are always amazed when listening to them.

    Now I know I can find all the necessary info if I ever have to fix them.

    Polk SDA1
    Marantz CD63 mkII KI
    Lynn Basik turntable
    Taga PF2000 power filter
    Cambridge CXN Streamer / DAC
    Yves Cochet PS-1 tube preamp
    Yves Cochet ALS-1 tube power amp
    Boite Noire power filter and rectifier for amp
    and obviously excellent interconnect and speaker cables
  • pitdogg2
    pitdogg2 Posts: 24,579
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    xschop wrote: »
    Wow, not even an SL1000 tweeter route-out.

    yes it is
  • F1nut
    F1nut Posts: 49,802
    edited May 2022
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    Angio II wrote: »
    I have exactly the same ones and bought them in San Francisco back in 1985 asd SDA1.
    They still deliver a great sound without having had to replace anything.
    People here in France are always amazed when listening to them.

    Now I know I can find all the necessary info if I ever have to fix them.

    Polk SDA1
    Marantz CD63 mkII KI
    Lynn Basik turntable
    Taga PF2000 power filter
    Cambridge CXN Streamer / DAC
    Yves Cochet PS-1 tube preamp
    Yves Cochet ALS-1 tube power amp
    Boite Noire power filter and rectifier for amp
    and obviously excellent interconnect and speaker cables

    Welcome to Club Polk

    You'd be amazed at how much better they would sound by upgrading the crossover components. The original electrolytic caps are way past their lifespan and will be out of spec.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • xschop
    xschop Posts: 4,704
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    pitdogg2 wrote: »
    xschop wrote: »
    Wow, not even an SL1000 tweeter route-out.

    yes it is

    Another one of Polk's early abandoned experiments?
    Don't take experimental gene therapies from known eugenicists.
  • pitdogg2
    pitdogg2 Posts: 24,579
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    xschop wrote: »
    pitdogg2 wrote: »
    xschop wrote: »
    Wow, not even an SL1000 tweeter route-out.

    yes it is

    Another one of Polk's early abandoned experiments?

    Most early Polk speakers sat on baffle. The cut out is definitely peerless/sl1000. I misread your post as you meant (I think) that it was not routed to inset the driver into the baffle.