I'm looking for input coupling caps for a headphone amp I'm building. The amp is discrete and the output is direct coupled. The input caps are 0.47uF.
I personally don't have an electronics background so can't reason why one design is better than the other, and for lack of better knowledge believe subjective opinions on whether boutique cap A is better than boutique cap B.
Reading other cap recommendation threads, subjective opinions about caps whether they are Mundorf, Jupiter, Jantzen, etc etc are quickly disregarded as snake-oil and request for measurements and numbers are requested as proof.
So my question here is directly to those who stick with the electronics theory, which brand / material type of film cap do you rely on if needed for input coupling?
Thanks
I personally don't have an electronics background so can't reason why one design is better than the other, and for lack of better knowledge believe subjective opinions on whether boutique cap A is better than boutique cap B.
Reading other cap recommendation threads, subjective opinions about caps whether they are Mundorf, Jupiter, Jantzen, etc etc are quickly disregarded as snake-oil and request for measurements and numbers are requested as proof.
So my question here is directly to those who stick with the electronics theory, which brand / material type of film cap do you rely on if needed for input coupling?
Thanks
At .47uf you can go with many of the industrial film capacitors available. Film/foil is probably extravagant, but mkp is good. Just find one with the right package for your PCB. I don't think you need to worry about voltage rating in a headphone application. Smaller package is beneficial in many ways from an installed loop inductance perspective and/or RF pickup.
There is also pps, but likely polypropylene will work.
Looking at mouser, I'm okay with all the manufacturers.
There is also pps, but likely polypropylene will work.
Looking at mouser, I'm okay with all the manufacturers.
What will fit?
You're probably looking at metallized polypropylene in the best case if you can fit it.
ECW-FD2W474J4 Panasonic Electronic Components | Capacitors | DigiKey
This is one of the physically smallest in that size.
If they are surface mount, PPS is probably the best you can do. If you need to go electrolytic to fit, then try something like Nichicon Muse ES or Panasonic SU (both bipolar) and go for a larger value.
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Thanks for the info.
The PCB allows for a generous sized cap in that location, there is space for about 42mm length.
At Mouser, the Cornell-Dubilier 930C and 940C seem most appropriate
The "audiophile" equivalent I was considering is a Jantzen Superior Z-Cap which cost around $11 each (vs $4.8 for the CDE), so not much difference there in terms of pricing.
The PCB allows for a generous sized cap in that location, there is space for about 42mm length.
At Mouser, the Cornell-Dubilier 930C and 940C seem most appropriate
The "audiophile" equivalent I was considering is a Jantzen Superior Z-Cap which cost around $11 each (vs $4.8 for the CDE), so not much difference there in terms of pricing.
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If you can find one that fits, I would try to get a "stacked" box type cap rather than an axial "wound" construction. I am not sure the one that I linked is actually stacked or if it is wound and dipped, but anyway, the stacked construction like Wima MKP should in theory have lower inductance. Not that it really matters. I'm sure the CDE cap you picked will be fine.
The only "upgrade" would be if you can find a film and foil PP cap (not metallized). I am not sure you can find one in 0.47uF though. Well - maybe you can if you're willing to go huge. I would not worry with an MKP cap though.
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The Wima MKP10 have 37.5mm lead outs which I could probably fit.
The Audiocap Theta is Polypropylene film and Tin foil and cost around $13, so again not a big diff in price, but that is not an "industrial" brand cap
The Audiocap Theta is Polypropylene film and Tin foil and cost around $13, so again not a big diff in price, but that is not an "industrial" brand cap
I'd just go with one of the metallized polypropylines. You might be able to go with smaller Panasonic or Wima and increase the value. I don't know what the cutoff frequency of the high-pass filter is but that would probably be better bang for your buck than going to a giant film and foil cap.
And if I were avoiding SMT, would this Kemet be equivalent?
Could you elaborate what advantages this has over a single metallized PP cap?
The Kemet looks fine if you don't mind paying over $4 a pop, compared to the 1206 version which will set you back $0.85 for ten (on Mouser). Unreasonably affordable for NP0 caps, I had to read the datasheet through to check its not a mistake!
Apart from the diminished size which means less noise pick-up, I can't think of any advantages of NP0 over metallized PP.
Apart from the diminished size which means less noise pick-up, I can't think of any advantages of NP0 over metallized PP.
Pps capacitors if you don’t have a lot of space , if you do have space buy any cde 940 941 or Orange drops 915/916 or even 225.
Why, when you can stack Panasonic ECPU if you love stacking so much, or just go for a single 1uF? Unlike that horror NPO, the ECPU approaches the sonics of snake oil.
No experience with those Panasonics myself, but they look interesting for where space is even more at a premium. They won't get used in filters though as their 20% tolerance is too wide but for coupling they look worth a try.
Silly prices for unnecessary specifications.
It is an amplifier for headphones, not a precise instrument working at VHF and above.
You may want to ask yourself why professional engineers and renown manufacturers, like Sony, Panasonic, Technics, Bose, Quad and even B&O use an electrolytic as a coupling device.
More than adequate in my professional opinion and it will save you from empty pockets, unless of course you want to waste your money just to make you think that it will be better, as many DIYers seem to do.
It is an amplifier for headphones, not a precise instrument working at VHF and above.
You may want to ask yourself why professional engineers and renown manufacturers, like Sony, Panasonic, Technics, Bose, Quad and even B&O use an electrolytic as a coupling device.
More than adequate in my professional opinion and it will save you from empty pockets, unless of course you want to waste your money just to make you think that it will be better, as many DIYers seem to do.
I have used these in similar locations, are fairly transparent, are a bit long however, might be a tight fit.
Polystyrene Capacitor K71-4 0.47uF 470nF 250V +/-5% ◊ (Diamond) 1pc.+ | eBay
Polystyrene Capacitor K71-4 0.47uF 470nF 250V +/-5% ◊ (Diamond) 1pc.+ | eBay
WOW is this thread convoluted the response that had the link to an informative article I read in 1980 is the only real science discussed but yeah dielectrics matter. Also understanding the diff between film and foil and where to apply it. Learning instead of an AD-HOC opinion can keep the snakes away from the door while you make your best choices.
Rest assured that Science and Technology have advanced immensely and any product from one of the large Industrial manufacturers will be VERY good and more than enough for the task.
Besides, an input capacitor is an "easy" job: almost non measurable current through them, and almost zero voltage drop between terminals, since value is usually chosen to cut frequencies well below the audible range.
My point is they are not stressed by any means so no need for exotic parameters or construction.
Besides, an input capacitor is an "easy" job: almost non measurable current through them, and almost zero voltage drop between terminals, since value is usually chosen to cut frequencies well below the audible range.
My point is they are not stressed by any means so no need for exotic parameters or construction.
Be sure they are not X7R or similar by mistake though, those distort a lot and are microphonic. C0G are extremely linear. 1206 is the smallest size you'll find 100nF in C0G