Capacitor placement and values
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MikeMoose
Posts: 9
Greetings! I have a pair of Polk 12 B speakers that I purchased in 1981 that have never been refurbished. They still sound OK to my aging ears but I’m sure they are suffering. I don’t pretend to be an electronics wiz but I have quite a bit of soldering experience so I’ve decided to recap them myself. Michael8it from a much earlier post used Erse capacitors and commented he was very satisfied with his results. I’ve decided to go with the same although they are now called MPX caps from US coils. They are still called Pulse X so I’m hoping they are at least as good in quality. In his original post, he shows a photo of his finished results. It appears the 55 micro and the 4.4 micro capacitors have swapped positions with each other in respect to their stock positions on my boards. I’m guessing that’s because the 55 micro that he used is quite a bit larger than the original stock 55 that came on the board. My question is because they’re connected in parallel does it matter which position they’re in and respect to each other? I’m guessing it’s OK to swap their positions. My other question is the capacitor values. The originals are 55 and 4.4. The closest MPX caps that I’ve got on order in value are 56 and 4.7. Again I’m guessing that they are so close it won’t make any difference. Any suggestions or comments would be appreciated, thank you.
Best Answer
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I tested a set of Erse caps sent to me by a well known member here. Ill be using them again.
I think your values will be close enough too.Don't take experimental gene therapies from known eugenicists.
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Thanks for your response xschop. Good to know, their already on order so I took a chance. Any comments on the positioning question?
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Post some pics for reference, but as long as the leads are soldered into correct locations, you're good to go.Don't take experimental gene therapies from known eugenicists.
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Ok. Those 2 positions shouldn't matter as they are parallel to each other in the schematic.Don't take experimental gene therapies from known eugenicists.
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The photo on the top is my speaker unaltered. The photo on the bottom is the recapped speaker from Michael8it. The yellow caps in the top photo are the 4.4 stock caps. The blue one is the 55 µF. In the bottom photo I believe the 55 µF cap is the large one to the extreme left and the smaller ones are his 4.4’s. I believe the circuit boards are identical. If you study the two photos you’ll see the capacitors are swapped in positions on the board which leads me to believe that their location, because they are in parallel, could be in either position.
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Thanks, that’s what I was hoping for because the space constraints are an issue with the larger 55 µF capacitor in the original position.
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Good deal. Let us know what you think about the cap upgrade.Don't take experimental gene therapies from known eugenicists.
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Will do. I’m currently having a 49 year old Marantz 4140 amp reconditioned ($$$). I plan to run that thru the polk’s before I recap them in hopes of seeing improvement before I recap the 41 year old speakers. I hope my 70 year old ears and tell the difference! This equipment is all very sentimental to me because I bought it all new. I gotta believe most of us on these forums I feel the same way.
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Just got my new capacitors in the mail today. Probably a very silly question but I wanna make sure I know what I’m doing before I dive into this. None of the stock capacitors on my existing board or the new capacitors that I just received have any polarity markings. I’m guessing they’re non-polarized which means I can install them in either direction? Just want to be sure.
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non-polarized
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Thank you very much
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With polypropylene caps I don't think it matters in a crossover circuit, in an active circuit the outside foil is supposed to go to the low impedance side of the circuit.
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The outside foil is supposed to go to the low impedance side of the circuit in an active circuit, however I agree with @invalid that it doesn't matter in a crossover circuit when using polypropylene caps.
