Polk Monitor 70 Series 1 Tweeters Almost Silent

2»

Comments

  • FestYboy
    FestYboy Posts: 3,861
    As far as insulation, yes, leads need to be insulated with some heat shrink and the exposed points can be hit with some hot glue or RTV. The resistor is not in a case, what you see IS the resistor (cast type).
  • Word. Any input on the gauge of wire required if I need to extend any capacitor or resistor leads? Also, does 1mm heat shrink sound right for capacitor and resistor leads? I am sure I'll have more questions soon. Thanks for all the input @FestYboy, @pitdogg2, and @VR3.
  • VR3
    VR3 Posts: 28,712
    You can probably use the left over lead from the short run of the capacitor, any normal heat shrink will work
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • pitdogg2
    pitdogg2 Posts: 25,509
    resistor should go OK just like it was on top, max gauge of wire is determined by the hole size on the board. I'm guessing here 16-18 gauge. I've never used any shrink tubing on resistor leads they need to shed heat and that may help contain said heat and melt. Do yourself a favor and look at that board good. You may be able to use one solder pad where the bypass cap was and one where the lytic was. This may help keep the cap on top. Just a thought
  • Viking64
    Viking64 Posts: 7,091
    New resisters are in order.
  • Since I've been waiting for my capacitors and resistors to arrive I've been doing more reading and watching. I've come across multiple threads and videos discussing capacitor polarity and quite specifically film capacitors. As I understand it, most if not all film capacitors are non polar. However there will be a lead connected to the outer foil of the capacitor. Apparently in some instances it can absolutely matter how you solder in the film capacitor and apparently in many instances it may not matter at all. I do not have any of the testing equipment used or mentioned in may of the videos and forum threads I've come across. I have some questions concerning this matter.

    Does anyone know if/how sonicap capacitors denote the outside foil lead and if it is accurate?

    Without having an oscilloscope and other testing equipment, is there a quick and dirty albeit effective way to determine which lead is connected to the outside foil? Some alternatives to the oscilloscope were using guitar amplifiers and some cables and alligator clips. I don't have a guitar amp but I do have some crown amps. Would an RCA cable and some alligator clips to one of the crown amp's input work about as well for a quick and dirty test?

    If I can determine the outside foil lead, how will I know which way to solder it onto the board? I don't have the old capacitors removed so I cannot see if the board has a clear indication. I read something about the outside foil lead should go to the lower impedance.

    For my replacement capacitors, I chose http://www.soniccraft.com/product_info.php/gen-sonicap-82-uf-200vdc-p-447 and http://www.soniccraft.com/product_info.php/gen-sonicap-10-uf-200vdc-p-450
  • pitdogg2
    pitdogg2 Posts: 25,509
    Since I've been waiting for my capacitors and resistors to arrive I've been doing more reading and watching. I've come across multiple threads and videos discussing capacitor polarity and quite specifically film capacitors. As I understand it, most if not all film capacitors are non polar. However there will be a lead connected to the outer foil of the capacitor. Apparently in some instances it can absolutely matter how you solder in the film capacitor and apparently in many instances it may not matter at all. I do not have any of the testing equipment used or mentioned in may of the videos and forum threads I've come across. I have some questions concerning this matter.

    Does anyone know if/how sonicap capacitors denote the outside foil lead and if it is accurate?

    Without having an oscilloscope and other testing equipment, is there a quick and dirty albeit effective way to determine which lead is connected to the outside foil? Some alternatives to the oscilloscope were using guitar amplifiers and some cables and alligator clips. I don't have a guitar amp but I do have some crown amps. Would an RCA cable and some alligator clips to one of the crown amp's input work about as well for a quick and dirty test?

    If I can determine the outside foil lead, how will I know which way to solder it onto the board? I don't have the old capacitors removed so I cannot see if the board has a clear indication. I read something about the outside foil lead should go to the lower impedance.

    For my replacement capacitors, I chose http://www.soniccraft.com/product_info.php/gen-sonicap-82-uf-200vdc-p-447 and http://www.soniccraft.com/product_info.php/gen-sonicap-10-uf-200vdc-p-450

    Don't over think think this, personally I've never ever had this be a problem.
    Put them in and call it a day.
  • Fair enough. It's quite easy to get a little OCD and carried away with all the reading one can do. While I am still waiting for parts, can anyone chime in with some recommendations for solder, flux, and what temperature I should be using? Please keep in mind I am exceptionally inexperienced with soldering. I've been practicing on some old broken stuff but I have some work to do, especially when it comes to de-soldering.
  • pitdogg2
    pitdogg2 Posts: 25,509
    Cardas quad solder is all you'll ever need. Flux is already in the solder.
  • VR3
    VR3 Posts: 28,712
    The capacitors used in a speaker circuit are bipolar, they go both ways

    I like 720 to 750 on my Weller but I do point to point. Monitor series circuit traces are stupid thin and easy to lift so don't hang out on it or get it to hot
    - Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
  • RandomNonsense
    RandomNonsense Posts: 19
    edited November 2018
    For the Cardas quad solder or any solder for that matter, any specific diameter I should be looking for? I am not quite sure how to pair up the component size with solder diameter size. I'm seeing 0.032" diameter for the Cardas I found on Amazon.
  • pitdogg2
    pitdogg2 Posts: 25,509
    edited November 2018
    Where are you ordering caps from?
  • RandomNonsense
    RandomNonsense Posts: 19
    edited November 2018
  • pitdogg2
    pitdogg2 Posts: 25,509
    get the cardas from soniccraft when you order.
  • I already ordered the caps and resistors from Sonic Craft. I found what looked to be the same solder on Amazon. Thanks for the recommendation.
  • FestYboy
    FestYboy Posts: 3,861
    For the Cardas quad solder or any solder for that matter, any specific diameter I should be looking for? I am not quite sure how to pair up the component size with solder diameter size. I'm seeing 0.032" diameter for the Cardas I found on Amazon.

    I prefer thicker diameter for tinning as it's less time on heat when trying to feed it on to the wire. Lessens the chance of cooking the sheath. For board work, the thin stuff is fine for me as all I'm doing is using the flux in the tin and what's left fills in any gaps.
  • Well, it's not pretty but the tweeters are working again. Thanks for all the advice everyone.

    uufsa3i5kb7y.jpg
    mesuzh09g9pw.jpg
    43gz56zeb81y.jpg
  • pitdogg2
    pitdogg2 Posts: 25,509
    Well you're correct it's not pretty. Teflon tubing will work better than shrink tubing in a very hot area.
    Nice job getting them working again. We all start somewhere and learn along the way.