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Post by jazzdad on Nov 4, 2023 11:17:06 GMT
Hi all,
I'm new here! I'm looking to replace the large power supply filter caps in my power amp which is a Parasound A21.
The OEM ones are 51mm diameter Rubycon 100v 22000uf with a ripple current of 10.2a.
They are now obsolete and the nearest equivalent I can find are Nichicon however their ripple current is 6.8a.
Would the difference in ripple current affect anything?
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Post by electronumpty on Nov 4, 2023 13:50:40 GMT
Hi, you're in the right place for techie support . I'm sure someone will be along soonish. Whenever I have replaced caps, I've made sure the voltage and temp rating are the same. Never looked at ripple, really but if there might be an effect then I'm sure someone will say.
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Post by jazzdad on Nov 4, 2023 14:17:50 GMT
Hi, you're in the right place for techie support . I'm sure someone will be along soonish. Whenever I have replaced caps, I've made sure the voltage and temp rating are the same. Never looked at ripple, really but if there might be an effect then I'm sure someone will say. Thanks Electronumpty! I'm no electronics expert, but these ones are screw in so giving replacement a go myself. Hopefully ripple current difference is fine as I cant find any other replacements anywhere |
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Bigman80
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Post by Bigman80 on Nov 4, 2023 14:34:20 GMT
Hi, you're in the right place for techie support . I'm sure someone will be along soonish. Whenever I have replaced caps, I've made sure the voltage and temp rating are the same. Never looked at ripple, really but if there might be an effect then I'm sure someone will say. Thanks Electronumpty! I'm no electronics expert, but these ones are screw in so giving replacement a go myself. Hopefully ripple current difference is fine as I cant find any other replacements anywhere Try looking for a larger voltage cap, which will improve ripple rating. 22000uf isn't an uncommon value so it should be possible to find something with better ripple than the Nichicon. |
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Post by jazzdad on Nov 4, 2023 15:15:23 GMT
Struggling to find caps over 100v. Weirdly enough the 63VDC one I've seen with same diameter has a higher ripple current of 33a.
Would replacing a 100v with 63v be ok?
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Post by brucew268 on Nov 4, 2023 15:21:39 GMT
The only interior photos I can find are the A21+ Halo, and I'm assuming you have the older A21 or you wouldn't be replacing caps.
I assume the caps of that size and rating are screw terminals not wire snap-in terminals (10mm apart)? The new Halo model has the cap leads down, is your older model leads down or wires and leads up?
What is the height for the caps and max height that could fit with clearance?
I wouldn't get lower ripple or the performance may not be as good as you are used to. Generally go for the highest ripple, lowest ESR available.
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Post by brucew268 on Nov 4, 2023 15:24:23 GMT
Struggling to find caps over 100v. Weirdly enough the 63VDC one I've seen with same diameter has a higher ripple current of 33a. Would replacing a 100v with 63v be ok? Probably not. You'd need to measure the voltage coming into the the caps to know for sure, but they tend to spec the voltage rating of the capacitors close to what is needed rather than way over.
If screw terminal, I may have found some that will work great, but the questions above are important.
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Post by jazzdad on Nov 4, 2023 15:37:44 GMT
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Post by brucew268 on Nov 4, 2023 15:44:21 GMT
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Bigman80
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Post by Bigman80 on Nov 4, 2023 15:45:15 GMT
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Post by jazzdad on Nov 4, 2023 16:09:18 GMT
This is great thanks Bruce. Same dimensions and terminal spacing too.
Does the difference between 22000uf and 20000uf make any difference? The amp was originally spec'd with 25000uf Elna caps but they changed them due to supply shortage.
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Post by brucew268 on Nov 4, 2023 16:41:22 GMT
I'll go out on a limb and say since the values are close, the capacitance value in the smoothing/resevoir caps is probably the least significant of the statistics to proper performance (voltage, ripple, ESR, etc., physical fit in the chassis, capacitance). So too low voltage rating and you blow something. The ripple and ESR ratings will most likely have more effect than the small capacitance difference.
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Post by jazzdad on Nov 4, 2023 16:47:18 GMT
Superb Bruce I really appreciate the help. Excellent price too!
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Post by jazzdad on Nov 5, 2023 21:17:53 GMT
I'll go out on a limb and say since the values are close, the capacitance value in the smoothing/resevoir caps is probably the least significant of the statistics to proper performance (voltage, ripple, ESR, etc., physical fit in the chassis, capacitance). So too low voltage rating and you blow something. The ripple and ESR ratings will most likely have more effect than the small capacitance difference. Hi Bruce would you mind checking these out aswell www.mouser.co.uk/ProductDetail/Cornell-Dubilier-CDE/DCMC233U100BD2B?qs=BG1FInsFbUQ93bzfgeV6ag%3D%3DSeem to be closer spec to the original Rubycons. You mentioned ESR rating; do these fair well? |
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Bigman80
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Post by Bigman80 on Nov 5, 2023 21:53:01 GMT
I'll go out on a limb and say since the values are close, the capacitance value in the smoothing/resevoir caps is probably the least significant of the statistics to proper performance (voltage, ripple, ESR, etc., physical fit in the chassis, capacitance). So too low voltage rating and you blow something. The ripple and ESR ratings will most likely have more effect than the small capacitance difference. Hi Bruce would you mind checking these out aswell www.mouser.co.uk/ProductDetail/Cornell-Dubilier-CDE/DCMC233U100BD2B?qs=BG1FInsFbUQ93bzfgeV6ag%3D%3DSeem to be closer spec to the original Rubycons. You mentioned ESR rating; do these fair well? The Kemets are better for ripple and life (18000hrs at 85c) The Cornell are better for ESR and Capacitance is higher, but life is only 2000hrs. Personally, I'd go for the Kemets due to the ripple and lifetime. Also only 5 mohms difference in ESR, so bugga all to worry about, but either will work. |
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Post by brucew268 on Nov 5, 2023 22:48:28 GMT
The Kemets are better for ripple and life (18000hrs at 85c) The Cornell are better for ESR and Capacitance is higher, but life is only 2000hrs. Personally, I'd go for the Kemets due to the ripple and lifetime. Also only 5 mohms difference in ESR, so bugga all to worry about, but either will work. Yes, I agree. I think the Cornell-Dubilier should be good, but the Kemets are nearly double the ripple which is better. ESR is similar between the two. And I have experience with the performance of Kemet ALS70 and like them. |
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