sx1500td main filter capacitor

Discussion in 'Pioneer Audio' started by john stumpf, Apr 20, 2017.

  1. john stumpf

    john stumpf AK Subscriber Subscriber

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    im having a hard time getting a main filter cap that will physically fit this set,im also looking for guidance as to the capacitance value. the oem cap is 2200 mfd at 80 volts. but is that the best cap for the job? then theres the issue of physical sizethers some wiggle room on diameter but not much the original was 41mm the absolute limit on length would be about 70mm. i just got off of mouser and i came up empty in a low leakage cap any recommendations and a source of supply would be welcome. its currently singing sweetly on it original '69 cap
     
  2. petehall347

    petehall347 the brandy coffee man Subscriber

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  3. john stumpf

    john stumpf AK Subscriber Subscriber

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    well yeah i know pete, but as they say a little knowledge can be a dangerous thing. in the process of doing this ive read as much as i can find about audio caps. and ill tell you, opinions seem to abound! i came to notice that they varied so much they were sometimes in conflict. one fella said that filter caps of '69 era were inferior to ANYTHING made today and therefor any thing new was better than oem! another suggested that they should be low leakage with high ripple. mark the fixer said that oem caps were made to -20% and +80% which means that my 2200 mfd cap could be usable in '69 at 3960 mfd!. and so the more i read the less i knew. to make matters worse the concept's of low esr and high ripple became meaningless as what do they mean by "low" and"high"?? what numbers am i looking for? and then finally as the tolerance for modern caps is much tighter,what is the "BEST" microfarad cap for this set? i was much happier before i investigated this ill tell you.i even have one of those on your link.its a epcos b41456-b9228-m. its rated at 12000 hrs,esr 80m0hms,and 13a of ripple. in the end i chickened out and decided i'd ask here. confusion reigns supreme! i know this set is old,it was made when i was just out of high school but im determined to do the best job i can
     
  4. rjsalvi

    rjsalvi Active Member

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    (chuckling) You're overthinking the process, John. Just about any proper value cap you drop in there by a reputable mfr. will work. However, some specs make a difference if for no other reason than longevity. Why low ESR? Heat dissipation. An electrolytic cap has fluid inside it and the more heat it's subjected to, the faster it will dry out. Ripple current rating? Too much ripple in a signal creates heat as well. Fortunately, modern technology has had the benefit of CAD (computer aided design) and most engineering and production anomalies can be worked out before a product is even built. So count me in the group that favors modern technology over "factory original". I don't think you'd have any issues if your capacitor selection included up to say, 2700uF and voltage rating to 100V. That may give you a bit more flexibility in finding the right physical size so it fits in your cap clamp. Obviously cap pin type and spacing are a big deal so you won't have to modify the pcb. And all cap mfrs. have a selection guide based on performance characteristics, i.e., here's one from Nichicon: http://www.nichicon.co.jp/english/products/alm_mini/index.html

    Really, it's not as big a deal as it seems. Details matter, but in some areas, the granularity of them isn't mission critical.
     
  5. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    john. I agree with rjsalvi on pretty much everything except size. Every Pioneer, allied, Sansui, or Fisher that has had 2200uf, I've put in 3300uf and bumped up the voltage one step (30 to 35, 50 to 63 etc.) with no problems except those that are 80 to 85 v. And that's a parts availability problem mor than anything else. No UPW or UHE type made that large so a UVZ or UVY is fine. A Nichicon UPW or UHE series is a low impedance type that is pretty much ideal for Power supplies. Which is why Mark the Fixer recommends that type in the 1st place. And he's been reverse engineering PIONEER's for the better part of 30+ years now to get the best performance, and longevity out of them. To paraphrase RJ "don't overthink the problem". UPW or UHE for power supply and UKL for signal paths. TVX for axials. And that's it for Electrolytics in PIONEER's. When a UPW or UHE isn't available use what you can get within reason. Todays caps have a cleaner and lower noise floor than most all caps from 1969-75. And audio grade caps(UFW & UKW) aren't any better other than to line Nichicon's pockets. I can see them in really hi end stuff like the sx-1980 where the amp board has more connections than your sx-1500td, but a standard cap works fine in the lower ended stuff.

    You'll play hell trying to find an exact match with value, voltage, AND diameter. Which gives you room to uprate the cap. In most cases even with a bump from 2200 to 3300 and a bump from 80v to 100v you're still gonna be slightly smaller than the original. Window weatherstripping around the cap so it gets clamped or stuffing the original cap with the new are options. Going even higher in value and voltage to get closer in diameter is another but don't overdo it. 80% higher value and 50% increase in voltage, and the 4th option is to disconnect the original underneath and put the new one underneath, connected to the circuit, with the original cap there for window dressing.

    IIRC the 1500 cap has soldered on wires, no pcb for the cap underneath. So either of the below will fit. You may have to solder crimp rings to the LGU cap to get a better wire solder joint.

    Leaded:
    647-UVZ2A332MRD 3300uf 100v. 25mm x 50mm 105*c rated, $5.61 ea.
    http://www.mouser.com/ProductDetail/Nichicon/UVZ2A332MRD/?qs=sGAEpiMZZMtZ1n0r9vR22cbP6Wf/HrkhzvI%2bzJvhzp4=

    Snap-in;
    647-LGU2A272MELC 100volts 2700uF 0.2 35x35 105c $4.09ea.
    http://www.mouser.com/ProductDetail/Nichicon/LGU2A272MELC/?qs=sGAEpiMZZMtZ1n0r9vR22TrbYqu733AyWKWwGwC246w=

    Larry
     
  6. john stumpf

    john stumpf AK Subscriber Subscriber

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    thanks fella's it was the last thing i had to do to finish this thing and i have a better understanding of whats involved, its a relic but ive grown quite attached to it. i like the idea of the rubber mounting it beats the hell out of wrapping a half roll of e tape around it. i read this but its true it DOES sound like a tube radio! ill go with the uv nichicon. by the way, did any of you get a notice in the mail inre to a class action suit against a bunch of cap makers being pursued by a legal firm in wisc.? i just picked it up in the diplomatic mail it was to do with price fixing
     
  7. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Got one a couple weeks ago.
     

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