Polk SDA SRS 3.1TL burnt choke coil on crossover board

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  • cortico
    cortico Posts: 587
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    F1nut wrote: »
    Refinishing any furniture lessens its value

    False.

    Not any, but if they're antiques or collectibles... It may!
  • F1nut
    F1nut Posts: 49,805
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    THX certification is nothing more than a guarantee the piece meets or exceeds certain specifications of sound quality. This is a good thing, so buy with confidence.
    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

  • daddyjt
    daddyjt Posts: 2,329
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    Nibs wrote: »
    ...Being a THX amp I am not sure of the sound staging. I thought that was more for surround than stereo...

    What you are probably thinking of here are THX certified speakers.... Lucasfilm dictates a very specific dispersion pattern for it's THX certification on speakers. This makes them less desirable for 2 channel music listening.

    THX certification on amps and receivers is never a bad thing...

    "Conservative Libertarians love the country, progressive leftists love the government." - Andrew Wilkow


    “Human beings are born with different capacities. If they are free, they are not equal. And if they are equal, they are not free.”
    ― Aleksandr Solzhenitsyn

  • Nibs
    Nibs Posts: 25
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    Copy that, Gentlemen. That's what I wanted to know. Thanks for the clarification. The THX amps are new to me, and I'm just not up to speed on them. I wouldn't mind picking this one up, but have not heard back.
    pitdogg2 wrote: »
    daddyjt wrote: »

    pretty bold statement as some of the best now use them for much more than sub amps. What F1 is stating is there are better amps for about the same coin that would be a better fit. IF LOUD is all you're after then by all means go for it, But if excellent articulation of the music with a wonderful sound stage with depth and width then you need to keep looking. There have been some excellent amps for sale here so keep posting and get your learn on. For most on here to be able to buy and sell you'll need 100 post. There might be a seller here who would sell you something, but that is their call. the 100 post rule was for to help keep people from getting took as we would be better acquainted with you if you post and stick around.

    pitdogg2, could you please provide me some examples of amps that would be better than the Crown for about the same coin?
  • leftwinger57
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    I'm going to 2nd on going w/ the Adcom GFA-555. I have one and it's uber powerful, doesn't ever even get warm driving multiple speakers (which I don't do) and powers my my '87 2Bs w/ ease. Generally on the used market they for $300 all day long w/ 200 wpc and specs on the example that I will show. This is the exact model I have. While not an arson investigator it does look like that burn pattern spread to that resistor near by.


    http://www.ebay.com/itm/Adcom-GFA555-2-Channel-Power-Amplifier-Rack-Mount-/301746140386?hash=item464178b4e2
    2chl- Adcom GFA- 555-Onkyo P-3150v pre/amp- JVC-QL-A200 tt- Denon 1940 ci cdp- Adcom GFS-6 -Modded '87 SDA 2Bs - Dynamat Ext.- BH-5- X-Overs VR-3, RDO-194 tweeters, Larry's Rings, Speakon/Neutrik I/C- Cherry stain tops Advent Maestros,Ohm model E

    H/T- Toshiba au40" flat- Yamaha RX- V665 avr- YSD-11 Dock- I-Pod- Klipsch #400HD Speaker set-

    Bdrm- Nikko 6065 receiver- JBL -G-200s--Pioneer 305 headphones--Sony CE375-5 disc
  • westmassguy
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    Looking at the schematic, if the Tweeter coil burned out, then the only path to ground would have been that Inductor. Since there's no fuse or Polyswitch, the coil took the brunt of it.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer

    dhsspeakerservice.com/
  • pitdogg2
    pitdogg2 Posts: 24,583
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    Nibs wrote: »

    pitdogg2, could you please provide me some examples of amps that would be better than the Crown for about the same coin?

    Adcom, Carver, Rotel, Parasound, Sunfire the list is endless.

  • Nibs
    Nibs Posts: 25
    edited September 2015
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    I'm going to 2nd on going w/ the Adcom GFA-555. I have one and it's uber powerful, doesn't ever even get warm driving multiple speakers (which I don't do) and powers my my '87 2Bs w/ ease. Generally on the used market they for $300 all day long w/ 200 wpc and specs on the example that I will show. This is the exact model I have. While not an arson investigator it does look like that burn pattern spread to that resistor near by.


    http://www.ebay.com/itm/Adcom-GFA555-2-Channel-Power-Amplifier-Rack-Mount-/301746140386?hash=item464178b4e2

    Thanks, leftwinger57 .

    Looking at the schematic, if the Tweeter coil burned out, then the only path to ground would have been that Inductor. Since there's no fuse or Polyswitch, the coil took the brunt of it.

    Copy that. The question is why? Since I no longer have that amp to see what it was doing I wont know the real reason. I will work on building some new boards and try again.

    Thanks, guys!
    Post edited by Nibs on
  • Nibs
    Nibs Posts: 25
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    pitdogg2 wrote: »
    Nibs wrote: »

    pitdogg2, could you please provide me some examples of amps that would be better than the Crown for about the same coin?

    Adcom, Carver, Rotel, Parasound, Sunfire the list is endless.

    Those are much more than the Crown XLS 1000 and XLS 1500 $ for $ and Watt vs Watt, but they are not the same type of build as the Crown. They are a much different animal and therefore a different sound. Thank you for the tips.
  • Nibs
    Nibs Posts: 25
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    F1Nut and all.... do any of you guys have a parts list and price for these boards? Thanks in advance!
  • F1nut
    F1nut Posts: 49,805
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    The boards are $100.00 for the pair.

    Per board...

    Caps:

    (2) 12uF
    (1) 24uF
    (1) 55uF

    Resistor:
    (1) 1.3 ohm 5 watt (get either the 10 or 12 watt Mills version)

    Inductors:

    (1) 0.3 mH/22 ga.
    (1) 1.25 mH/18 ga.
    (1) 1.0 mH/18 ga.
    (1) 18 mH/22 ga.
    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

  • Nibs
    Nibs Posts: 25
    edited September 2015
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    Right on, man. Thanks! What about the parts that the wiring harnesses plug into? Is it easy enough just to reuse the old ones? I was informed that they could melt if your not careful removing them. Can I reuse the existing inductors (except the melted one of course)? What is the difference in the 10 or 12 Watt version of resistor compared to the original 5 Watt? Do I stick with the 1.3 Ohm?
  • pitdogg2
    pitdogg2 Posts: 24,583
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    Nibs wrote: »
    Can I reuse the existing inductors (except the melted one of course)? What is the difference in the 10 or 12 Watt version of resistor compared to the original 5 Watt? Do I stick with the 1.3 Ohm?

    yes you can use old except for the cook one. there is no difference except they handle more power, consider it insurance. Yes stick with 1.3ohm

  • gimpod
    gimpod Posts: 1,793
    edited October 2015
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    May be a bit late but been laid up trying to heal a bad foot for awhile, may end up losing it don't know.


    This is the Air Core Inductor you want to order as it's a good match spec wise to the original, when replacing inductors it's best to try and say as close to the original so not to change the voiceing of the speaker, you'll need to order 2.

    Inductor DCR Insanity For SDA's

    Part number, mH, DCR, AWG:
    000-1452, 0.300mH +/-3%, 0.550Ω DCR, 22AWG.

    Go here www.gimpod.com (the support site) for Schematics, Part List, Part Placement Guide and the Hints and Tips section. for info on the boards.

    Don't reuse the old pin headers you can get new ones at mouser, check my site for links and part numbers.
    “The two most important days in your life are the day you are born and the day you find out why.” ~ Mark Twain
  • Nibs
    Nibs Posts: 25
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    Thanks, pitdogg2 and gimpod! Thanks for the links and part numbers. I actually found two of those inductors from Polk. I didn't want to drop the coin on all new boards, caps, etc., so I just swapped the inductors. If I decide to build new boards down the road I have all of your advise, links, and info saved. Thank you very much for all the input!

    My speakers are back, and they are magnificent! :)

    I picked up an Sony STR-D90ESG to upgrade from my newer Sony STR-DE835. I also have the Marantz 2230. I also spoke to my stereo repair guy about the Crown Class Ds. He said he is getting rid of all of his older gear and going with the Crowns. He put them on his oscilloscope and distortion analyzer and they have checked out beautifully. The only question still out there is their longevity. Time will tell, but for the money they are fabulous, powerful, light, cool (as in heat) and versatile units!

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  • westmassguy
    westmassguy Posts: 6,850
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    What's the gauge on that inductor? Doesn't look like #22 gauge from the photos.
    Home Theater/2 Channel:
    Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
    Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
    Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
    Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
    Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer

    dhsspeakerservice.com/
  • RandyCroissant
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    I agree with Dave, looks like the wrong size wire. That could possibly lower the DCR of the coil and change the voicing of the tweeter.
    Yamaha RXA1030, Yamaha CD-S2100, Yamaha AS-2200, Bluesound node 2i
    Polk SDA2btl highly modded
    Polk SDA 1C modded
    Polk CS350 LS x2
    Kimber 8TC
    Sony 55" Bravia
    Wish list SVS sub

  • F1nut
    F1nut Posts: 49,805
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    I also agree, that's the wrong inductor.
    I didn't want to drop the coin on all new boards, caps, etc., so I just swapped the inductors.

    You have no idea what you are missing.
    I also spoke to my stereo repair guy about the Crown Class Ds. He said he is getting rid of all of his older gear and going with the Crowns.

    Time for a new tech.
    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

  • F1nut
    F1nut Posts: 49,805
    edited October 2015
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    NM
    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

  • tlwing
    tlwing Posts: 13
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    This thread is from 2015 and I by luck came across what is a nice read. I process two vintage amps that are earmarked for friends as soon as I furnish the speakers and a turntable for each amp. I also picked up a pair of Polk 3.1 tl’s that are going into my system. I’m currently saving for the parasound JC5 and 3 months to go and viola. I’d love to hear any opinion regarding this match,JC 5 and the 3.1’s. I obtained these speakers blind and loaded them up to help out a friend with little room. When I got them home I was surprised at the quality top to bottom. They are rated at 50-500 w my current Marantz 2252 is ok but I think there is more hence the Parasound., So opinions suggestions are appreciated.
  • F1nut
    F1nut Posts: 49,805
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    They are rated at 50-500
    Worthless rating, ignore it.

    Any amp you're considering must be common ground unless you use the AI-1 or Dreadnought isolation transformer.

    Amperes (current) matters more than watts.

    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

  • Mike Reeter
    Mike Reeter Posts: 4,314
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    tlwing wrote: »
    This thread is from 2015 and I by luck came across what is a nice read. I process two vintage amps that are earmarked for friends as soon as I furnish the speakers and a turntable for each amp. I also picked up a pair of Polk 3.1 tl’s that are going into my system. I’m currently saving for the parasound JC5 and 3 months to go and viola. I’d love to hear any opinion regarding this match,JC 5 and the 3.1’s. I obtained these speakers blind and loaded them up to help out a friend with little room. When I got them home I was surprised at the quality top to bottom. They are rated at 50-500 w my current Marantz 2252 is ok but I think there is more hence the Parasound., So opinions suggestions are appreciated.

    I had a JC5 driving a pair of 2.3TL's and 3.1TL's. As long as I keep the JC5 in the first few watts of Class A, the Amp sounded extremely good with the SDA's.

    But, when I would call for some power, the JC5 would become strident very quickly. I moved back into Tube Amps.

  • pitdogg2
    pitdogg2 Posts: 24,583
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    Interesting about your JC5 and SDA.
  • Mike Reeter
    Mike Reeter Posts: 4,314
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    pitdogg2 wrote: »
    Interesting about your JC5 and SDA.

    The JC5 is a powerhouse, with what seemed like an unlimited amount of current. The issues with the Amp becoming too analytical, were probably due to my hearing loss and the necessity of wearing hearing aids.

    To an individual with 'normal' hearing, the JC5 could be the perfect Amplifier. I just prefer a warmer presentation, detailed yet smooth can be tough at times.