Polk Monitor 7 crossover upgrade question

maawr1230
maawr1230 Posts: 3
edited November 28 in Vintage Speakers
I am trying to teach myself how to recap and see lots of different information online. I have been reading posts on this forum and understand that Sonicap is who to use. The stock crossover has a 3.4uf Electrolytic cap on it and I was wanting to know if I can change it out with a film cap or do I keep it Electrolytic? I apologize if this is a question already asked and answered on the forum. I am looking at using the Gen 1 Sonicap capacitors and Mills resistors. Also it looks like I can use a Mills .5ohm for the poly switch replacement? Thank you guys in advance.
· Share on FacebookShare on Twitter

Best Answer

  • Toolfan66
    Toolfan66 Posts: 17,306
    Answer ✓
    I have used many different caps on many different Vintage Polk Speakers over the years, and IMO, Sonicaps and Vintage Polks = Magic..

    YMMV.

    Polk Audio SDA 2.3tl Fully Hot Rodded. 😎

    SVS SB16 X2

    Cary SLP-05/Ultimate Upgrade.
    Cary SA-500.1 ES Amps
    Cary DMS 800PV Network
    OPPO UDP 205/ModWright Modification
    VPI Scout TT / Dynavector 20x2
    Jolida JD9 Fully Modified

    VPI MW-1 Cyclone RCM

    MIT Shotgun 3 cables throughout / Except TT, and PC’s
    · Share on FacebookShare on Twitter

Answers

  • maawr1230
    maawr1230 Posts: 3
    ffsjkrndhptz.jpg

    here a picture of my crossover.
    · Share on FacebookShare on Twitter
  • pitdogg2
    pitdogg2 Posts: 25,574
    edited November 28
    That is a 34uf NOT 3.4uf. you will need to use two 17uf to get the value. When you parallel two caps to make value you want to be as close to half value as possible. In other words do not use a 30uf and a 4uf to make value. To use a 30 and a 4 the smaller cap will act more like a bypass cap which is not what you want. Make your resistors higher wattage than stock, use 10 or 12 watt resistors, more better.
    Put your 12uf poly cap on first then the paralleled caps on second. That way you can use double sided foam tape on the 12uf to help support the two paralleled caps. Understand that the poly caps will be much bigger than the caps now, so you must get a little creative to fit all. With the one hole in the board near the inductor you can run a long zip tie through to the edge and zip tie all down.
    To answer your question Yes you want to change out that 34 electrolytic. It is way past its prime and could be way past its value as it was most likely +/- 10% anyway.

    Clear as mud 😉
    · Share on FacebookShare on Twitter
  • maawr1230
    maawr1230 Posts: 3
    thank you so much for the answer, I sincerely appreciate it. I knew I came to the right place
    · Share on FacebookShare on Twitter
  • F1nut
    F1nut Posts: 50,654
    Sonicap has the 34uF, https://www.soniccraft.com/product_info.php/gen-sonicap-34-uf-200vdc-p-4638?osCsid=fben0qhm9d6sq60ql5avmr29q0
    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

    · Share on FacebookShare on Twitter