I did some reading on increasing the size of a coupling cap, and it seems to be that it’s really circuit dependent. I have this pho preamp, and these caps are the last in the circuit which connected to the rest of the preamp.
The two I’m specifically talking about are C415 and C416. They are 0.47 uF mylar or maybe polyester. I have some Panasonic polypropylene in that value, but I’m wondering what effect it would have if I increased the size. 0.68? 1?
I have some pretty nice quality polypropylene when I get into the 1 microfarad and above range. Out of curiosity, how high could I go? Could I put 2.2 in and see a benefit in the audio? or should I stay lower closer to the 1 microfarad? Or should I stick with 0.47?
Dan
The two I’m specifically talking about are C415 and C416. They are 0.47 uF mylar or maybe polyester. I have some Panasonic polypropylene in that value, but I’m wondering what effect it would have if I increased the size. 0.68? 1?
I have some pretty nice quality polypropylene when I get into the 1 microfarad and above range. Out of curiosity, how high could I go? Could I put 2.2 in and see a benefit in the audio? or should I stay lower closer to the 1 microfarad? Or should I stick with 0.47?
Dan
It depends on the input resistance of the following circuit (usually a 10k volume control).
If the capacitor does see a 10k load, then a 10uF coupling capacitor would be appropriate.
I would not go any larger than 10uF though.
However, if you want the capacitor to have a filtering effect on low frequency noise,
whether record noise or 1/f noise from the circuit, then a smaller value could be used,
from around 0.47uF to 1uF (with a 10k load).
The choice of dielectric type is up to you.
If the capacitor does see a 10k load, then a 10uF coupling capacitor would be appropriate.
I would not go any larger than 10uF though.
However, if you want the capacitor to have a filtering effect on low frequency noise,
whether record noise or 1/f noise from the circuit, then a smaller value could be used,
from around 0.47uF to 1uF (with a 10k load).
The choice of dielectric type is up to you.
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I agree with Ray:
I would suggest the 0.47uF value was put there for reasons of available space - or to roll off the LFs.
I myself always use 1uF or 2.2uF.
2.2ufd/63vdc WIMA MKP.... https://www.wima.de/wp-content/uploads/media/e_WIMA_MKP_2.pdf
https://www.mouser.ph/ProductDetail/WIMA/MKS2-2.2-63-10A?qs=pCRgUvwHhz/efVpVlUImZw==&_gl=1*ghta3l*_ga*MzExMzYwMTQyLjE2MjAzMDUwMTA.*_ga_15W4STQT4T*MTcxNTk4NjgwMi4xMy4wLjE3MTU5ODY4MDMuNTkuMC4w*_ga_1KQLCYKRX3*MTY5MDM0ODUyNi4yLjAuMTY5MDM0ODU0MS40NS4wLjA.
https://www.mouser.ph/ProductDetail/WIMA/MKS2-2.2-63-10A?qs=pCRgUvwHhz/efVpVlUImZw==&_gl=1*ghta3l*_ga*MzExMzYwMTQyLjE2MjAzMDUwMTA.*_ga_15W4STQT4T*MTcxNTk4NjgwMi4xMy4wLjE3MTU5ODY4MDMuNTkuMC4w*_ga_1KQLCYKRX3*MTY5MDM0ODUyNi4yLjAuMTY5MDM0ODU0MS40NS4wLjA.
Okay, so it sounds like I can go up in value no problem. 10uF would be way too large. I think the largest I could physically fit are maybe 3.3. I have some 1uF that are enormous, I guess it just depends on the capacitor. I don’t about the filtering effect, but I have read that when you increase the coupling passenger size you get improved bass response. Don’t know how true that is.
So you don’t think I will gain much by going to a different size? Are you saying the original is a metallized polypropylene? out of curiosity, what makes you think that? The service manual just states that it is a film, but I don’t think you run into too many poly propylene from this era. The input has been taken care of already using a 2.2 uF film. Or are you suggesting I go with a different size for the input?
Dan
Values up to 10uF could give an audible improvement in the bass, depending on the rest of the system.
You don’t think there is any benefit from upgrading to a better quality film, like polyester to polypropylene?
Any recommendations? I’ve got these ASC and TRW that I know are polypropylene, just not sure of their “audiophile” quality, plus I have a crap load.
Though the last ones are only 1 uF.
I have these Wima, they’re large and will fit weirdly on the board.
These are 2.2 uF polycarbonate which I’ve read are considered better than polypropylene.
I have these 1.8 uF MKP10s as well. As with these and the 2.2 Wima polycarbonate I have crap loads so be nice to use them.
Should I put the same exact caps at the input as the output?
I also have a bunch of your average round polypropylenes I generally use in speaker crossovers, like Audyn Q4, Solen, Eton and a few others. I feel like if I were to stand them on end I could possibly get a 3.3 to maybe a 6.8uF
Dan
Though the last ones are only 1 uF.
I have these Wima, they’re large and will fit weirdly on the board.
These are 2.2 uF polycarbonate which I’ve read are considered better than polypropylene.
I have these 1.8 uF MKP10s as well. As with these and the 2.2 Wima polycarbonate I have crap loads so be nice to use them.
Should I put the same exact caps at the input as the output?
I also have a bunch of your average round polypropylenes I generally use in speaker crossovers, like Audyn Q4, Solen, Eton and a few others. I feel like if I were to stand them on end I could possibly get a 3.3 to maybe a 6.8uF
Dan
Attachments
The input 2.2uF 25V electrolytic could be replaced by a film capacitor in the range 1uF to 2.2uF value, at a higher DCV if possible.
There's no actual benefit to a value any larger than that.
However, the capacitor's physical size should be small to avoid noise pickup, and stray coupling to and from elsewhere.
I would only use physically large capacitors at a low impedance circuit node, like a power supply or at the main audio output.
I would tend to use a Nichicon UES bipolar electrolytic, 1uF 50V, if you can find them (they are discontinued).
But they are very high quality, and are also very small.
Digikey still does have the 2.2uF at 50V, which would also work well.
https://www.digikey.com/en/products/detail/nichicon/UES1H2R2MDM1TD/4317415
There's no actual benefit to a value any larger than that.
However, the capacitor's physical size should be small to avoid noise pickup, and stray coupling to and from elsewhere.
I would only use physically large capacitors at a low impedance circuit node, like a power supply or at the main audio output.
I would tend to use a Nichicon UES bipolar electrolytic, 1uF 50V, if you can find them (they are discontinued).
But they are very high quality, and are also very small.
Digikey still does have the 2.2uF at 50V, which would also work well.
https://www.digikey.com/en/products/detail/nichicon/UES1H2R2MDM1TD/4317415
It could also result in the rumble component being more audible, or excessive speaker cone motion if taken to an extreme.
Mike
Oh okay cool, go with the muse ES? I have hundreds of both 1 uF and 2 uF in the ES line, I bought thousands of Nichicon stock when word got out about their discontinuation. So use that over film. Thank you for that, that’s great news. With your wording, would you use 1 uF over 2.2?
Was there any capacitors I posted photos of that looked like good candidates for the output caps? I have these others like I said, used for speakers, but would be perfectly fine in here. I have these Eton which are 6.8 uF 160v. Eton makes great stuff.
It would be a tight fit, but I can get these 10 uF Q4 to fit, so in this series I have on hand 1, 2.2, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2, and 10.
These, Eton, or one of the Wima??? Rayma, 10uF the best, or just the highest? What would you all use?
Thank you,
Dan
i get the right sized polypropylenes and forget about it...i am not a capacitor guy...