SDA-2B Caps

Do these really need to be replaced?hiyucrg1p7a5.jpg
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Comments

  • F1nutF1nut Posts: 39,783
    Yes.
    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."


  • jdjohnjdjohn Posts: 348
    Thanks, Jesse. And guaranteed benefits are...
  • F1nutF1nut Posts: 39,783
    Mo' better sound.
    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."


  • NightfallNightfall Posts: 7,503
    Drivers playing the frequencies they're supposed to be playing again.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.
  • F1nutF1nut Posts: 39,783
    The original mylar and electrolytic caps are general run of the mill stuff. Replacing them with superior poly caps will net better sound, but use something better than Solen or Dayton. Good choices would be Sonicap and Clarity. You should also upgrade the resistors, I prefer Mills.

    I don't know anyone that has regretted upgrading. Most say they wish they'd done it sooner.
    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."


  • Rolll the poly filll back up.
    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk Signature S60's;Cables: Wireworld Eclipse IC; Audioquest Big Sur IC; Zu Audio Mission speaker cables; PS Audio AC-3 power cords, all into a PS Audio Dectet Power center.

    All TV's sound enhanced by Polk Magnfi Mini's.

    Other; SDA2BTL's, M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage.

    Political memes posted as fact and accepted as fact, are sign language of the ignorant, for the ignorant

    tonyb said " but even socialists can do a good thing here and there
  • I made the changes recommended here to my 2bs and was floored at the improvement.
    Yamaha RXA1030, Yamaha CD
    Polk SDA2btl highly modded
    Polk SDA 1C
    Polk CS350 LS x2
    Polk m5jr
    Kimber 8TC
    Sony 55" Bravia
    Wish list SVS sub

  • voltzvoltz Posts: 4,945
    Dave did my crossover for my CRS+'s and they I believe are identical to the 2B's crossover in design.

    here a pic of the crossover after he ws done and the little white 5.6 cap is the shunt cap? that made it a 4.1 TL crossover so I could use the new 1RDO-198 tweeters :)

    fvp3z1qfn9jn.jpg
    2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge

    HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD
  • Dave does good work, doesn't he.
    Yamaha RXA1030, Yamaha CD
    Polk SDA2btl highly modded
    Polk SDA 1C
    Polk CS350 LS x2
    Polk m5jr
    Kimber 8TC
    Sony 55" Bravia
    Wish list SVS sub

  • teekay0007teekay0007 Posts: 2,041
    For the OP - if you're unaware, the Dave mentioned above is member westmassguy. He's done the upgrade work for several others here.
  • jdjohnjdjohn Posts: 348
    Thanks for all the input and recommendations. Dave has an eBay listing for servicing that I have kept bookmarked for a while. Might be time to pull the trigger, although these look like something I could actually do.

    I got a pair of Infinity RSIIIa this week, so the SDAs have lost a little luster in their current state.
  • westmassguywestmassguy Posts: 6,037
    voltz wrote: »
    Dave did my crossover for my CRS+'s and they I believe are identical to the 2B's crossover in design.

    here a pic of the crossover after he ws done and the little white 5.6 cap is the shunt cap? that made it a 4.1 TL crossover so I could use the new 1RDO-198 tweeters :)

    fvp3z1qfn9jn.jpg

    5.8uf Brother
    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
    Cables: Speaker: Furez 10/2 with GLS Locking Banana Plugs
    Interconnect: Furez 10/2 with SpeakONs
    ICs: Custom Furez by Douglas Connections
    Den:
    Bose 901 Series II Continentals Restored, Re-Built Equalizer with Elna Silmic IIs, Sonicaps, and Silver Mica Caps
    Carver CT-3 Pre, Carver C-500

    dhsspeakerservice.com/
    Exclusive Distributor of Gimpod's Custom SDA Circuit Boards

    "And keep her under 70, would you, huh? Betty likes a slow ride"
  • voltzvoltz Posts: 4,945
    opps! thank you. I'm glad you here Brother to keep me from missing up B)

    Also I think the Gimpod boards would make this a lot easier to upgrade!
    2 ch- Polk CRS+ * Vincent SA-31MK Preamp * Vincent Sp-331 Amp * Marantz SA8005 SACD * Project Xperience Classic TT * Sumiko Blue Point #2 MC cartridge

    HT - Polk 703's * NAD T-758 * Adcom 5503 * Oppo 103 * Samsung 60" series 8 LCD
  • jdjohnjdjohn Posts: 348
    Crossovers removed from both now. The left xover has different capacitors than the right. The yellow one on the left is not round - it's flatter with rounded edges. And the blue ones are different as well, with no hot glue applied to them or that winding on the left. Maybe they've been changed before? I will do them all anyway...just interesting.
    lyagyfsmfh7z.jpg
    nmqc8raqd1mw.jpg
    Is it normal to not have any polyfill in the bottoms? I know those woofers are just passive radiators, but still...
    e2vfod0vbtmk.jpg
    And then there's these staples in the bottom of the right cabinet. I tried hammering one down, but it's awkward striking it inside, and it tends to just bend over. Should I pull them and put in new staples or nails?
    0r9m0j8q6kst.jpg

    Thanks for all the advice, guys!
  • The poly fill should be tucked up behind the mid woofers as for the staples I would pull them out, I didn't have those in my 2bs.
    Yamaha RXA1030, Yamaha CD
    Polk SDA2btl highly modded
    Polk SDA 1C
    Polk CS350 LS x2
    Polk m5jr
    Kimber 8TC
    Sony 55" Bravia
    Wish list SVS sub

  • F1nutF1nut Posts: 39,783
    The yellow caps are mylar, it doesn't matter what shape they are as long as the values are the same. That would go for the blue electrolytic caps top.

    As Randy stated, the poly fill should be behind the mids. If you find any down around the PR, shove it back up and staple it to the cabinet. The large staple nails at the bottom were meant to help secure the end cap. Yours were never driven home.
    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."


  • jdjohnjdjohn Posts: 348
    Thanks, guys. From the schematics I have seen, C-4 should get a 0.1-0.5 ohm resistor instead of the 'nasty' polyswitch. I can't really tell what I currently have there, but will go ahead and put a new resistor. And then would S-1 just need to be a jumper at that point? Looks like it currently has a very small film cap.

    Regarding those staples: as mentioned, I don't think I can effectively drive them home as they are, so reckon I will yank them. The end cap seems secure, though...maybe there was glue used underneath? Should I hammer some smallish nails through just to be safe?
  • pitdogg2pitdogg2 Posts: 10,012
    edited November 2016
    jdjohn wrote: »
    Thanks, guys. From the schematics I have seen, C-4 should get a 0.1-0.5 ohm resistor instead of the 'nasty' polyswitch. I can't really tell what I currently have there, but will go ahead and put a new resistor. And then would S-1 just need to be a jumper at that point? Looks like it currently has a very small film cap.

    The polyswitch IS S-1 little square blue thing that is where a resistor should go. The C-4 I believe is the 750pf bypass cap. (I believe). With better poly caps this is no longer needed, A jumper might need to go here. I have not done any with these boards mine have all been the older two board XO's. I cannot say with certainty that a jumper needs to take its place in C-4.


    IF you plan on doing these yourself (Easy to do) I would buy the larger boards from Dave(westmassguy) that Gimpod designed. Much larger fit everything mo better.


  • C-4, just remove no jumper required.


    2 channel: Anthem 225 Integrated amp; Parasound Ztuner; TechnicsTT SL1350; Vincent PHO-8 phono pre; Marantz CD6005 spinner; Polk Signature S60's;Cables: Wireworld Eclipse IC; Audioquest Big Sur IC; Zu Audio Mission speaker cables; PS Audio AC-3 power cords, all into a PS Audio Dectet Power center.

    All TV's sound enhanced by Polk Magnfi Mini's.

    Other; SDA2BTL's, M10 series II, M7C's, Hafler XL600 amp, RB-980BX, Parasound HCA-1500 amp , P5 preamp, all in storage.

    Political memes posted as fact and accepted as fact, are sign language of the ignorant, for the ignorant

    tonyb said " but even socialists can do a good thing here and there
  • F1nutF1nut Posts: 39,783
    edited November 2016
    The end caps were glued as well. If yours seem secure as is and you want to remove the staples be sure to fill the small holes they will leave.
    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."


  • jdjohnjdjohn Posts: 348
    Got it, thanks fellas. I think I'll actually put a Vishay MKP1837 0.01uF into C-4...read some good things about that tweak, and of course replace S-1 with the resistor. I'll also pull those staples and fill the holes with small nails that match the length of the staples. And I'm going with Clarity caps (thanks, Jesse). They sell a 40uf, so I won't have to put two 20's in parallel for C-2, and they seem to be at a good price point for the quality.
  • F1nutF1nut Posts: 39,783
    edited November 2016
    Do not use a bypass cap with poly caps. For starters, it's not needed and secondly it causes artifacts, which at first may sound kind of cool, but in short order becomes annoying as hell.

    Fill the holes with a sealant like Loctite Power Grab. Do not use a silicone based product.
    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."


  • NightfallNightfall Posts: 7,503
    F1nut wrote: »
    Do not use a bypass cap with poly caps. For starters, it's not needed and secondly it causes artifacts, which at first may sound kind of cool, but in short order becomes annoying as hell.

    Are these artifacts only an issue with poly caps or also electrolytic?
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.
  • F1nutF1nut Posts: 39,783
    edited November 2016
    The silver mica that Polk used is a bypass cap, but I can't recall hearing the artifacts on stock SDA's.

    The idea behind a bypass cap is to use a very small valued "fast" cap to improve the performance of an electrolytic. I can see the validity there, but when you are already using a superior poly cap, it doesn't need help.
    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."


  • VSAT88VSAT88 Posts: 578
    I have done for the most part what F1 and westmass said with my SDA 2B (as well as my SDA SRS 2s) and I am most pleased. The guys here are awesome. My crossovers on the SDA 2B speakers are mounted on plastic standoffs that come off the large inductor . That was a problem that I have not fixed yet and it was a pain to deal with because I did the networks in stages. I am going back in to install hurricane nuts and when I do you can bet I will fix the plastic stand off issue somehow. I too used Clarity Caps and they are great. At least I like the sound I am getting. Once I went to Polk SDA speakers all the rest went to...rest..
  • jdjohnjdjohn Posts: 348
    There is a fair amount of history on this bypass topic, and actually specific to that Vishay cap being used. I should have checked earlier, but luckily those little guys are only a buck each if I end up tossing them.

    It sounds like the sonic effect must be a slight echo like in a concert hall, which is due to the different speed at which the electrons go through the bypass cap compared to the primary cap, arriving at a slightly different time, thus a faint echo. Some folks may find it desirable for certain types of music, I guess. A comment in one thread compared it to the old sine wave clipping analogy of tube vs solid state amps. Of course I have no first-hand experience.
  • F1nutF1nut Posts: 39,783
    I threw away some bypass caps that cost a lot more than a buck. The effect was that bad.

    Again, it has some validity when used with "slow" electrolytic caps. It has no validity when using an already "fast" poly cap. The echo you speak of, the artifact I speak of is not present in live performance music.
    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."


  • jdjohnjdjohn Posts: 348
    It *shouldn't* be present in a recording, but sometimes is, although not desirable. Accentuating it during playback would certainly not be a good thing. I don't think I'll risk it. Thanks for the info, Jesse.
  • jdjohnjdjohn Posts: 348
    edited November 2016
    Out with the old.
    zflam10saqqk.jpg
    Looking at the left crossover (see my earlier pics above), I think I'm going to move that smaller winding to the edge of the board, just like the one on the right (which is covered with glue). I think I'm going to need that extra real estate for the new, bigger caps. Someone was gettin' crazy with the Cheeze Whiz on that winding on the right.

    Interesting how the old yellow mylar cap is rated in Joules instead of (u)Farads. I know there's some math there involving Coulombs for the conversion, but it's too early in the day for that.
  • pitdogg2pitdogg2 Posts: 10,012
    jdjohn wrote: »
    Interesting how the old yellow mylar cap is rated in Joules instead of (u)Farads. I know there's some math there involving Coulombs for the conversion, but it's too early in the day for that.

    How is it rated in joules?

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