Is there any performance difference (line-level EQ circuit) between Wima FKP2 and MKP2 capacitors? Both are polypropylene.
But MKP2 is metallized while FKP2 is aluminum foil cap, which makes it a superior cap.
FKP2 Perceived performance is superior too, more open and detailed sounding.
Buy them in 2.5% or 1% precision if you value (and you should) having copper leads instead of steel ones.
Doubt the difference can be measured, as ESR is normally too low to matter whether its foil or metallized in a capacitor in a signal level circuit where impedances are in the k-ohm range. For a high current application like a crossover foil would be more robust, although stacking geometry can make a difference - basically low ESR is needed more at higher currents.
The self-resonant frequency might be useful to know in case that differs, as that might influence top end response in a large value capacitor.
It comes down to which parameters matter for the particular application.
Measure the case size to ensure a fit, but for line level filtering, the FKP will win every time.
Another excellent choice for that application would be the emz polystyrenes.
Another excellent choice for that application would be the emz polystyrenes.
Thanks for the responses. The FKP is certainly MUCH bigger, with a footprint ~5 times larger than the MKP. Also about 50% more $$. Hmmmm......
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FKP = film cap with polypropylene dielectric
MKP = metalized polypropylene cap
The FKP has lower dissipation factor than the MKP at frequencies of 100 kHz or above. I doubt you'll be able to measure any difference in system performance at audio frequencies between the two caps.
Tom
MKP = metalized polypropylene cap
The FKP has lower dissipation factor than the MKP at frequencies of 100 kHz or above. I doubt you'll be able to measure any difference in system performance at audio frequencies between the two caps.
Tom
Thanks for reminding me of the Bateman paper. Upon re-reading it,Cyril says:
"All metallised film and many foil and film capacitors use a ‘Schoop’ metal spray end connection to connect the capacitor electrodes to the lead-out wires.I have measured many metallised film capacitors having very large third harmonic levels, frequently as much as +20 dB higher than others in the same batch.I have not found this problem when foil electrodes are used with the same dielectric."
"All metallised film and many foil and film capacitors use a ‘Schoop’ metal spray end connection to connect the capacitor electrodes to the lead-out wires.I have measured many metallised film capacitors having very large third harmonic levels, frequently as much as +20 dB higher than others in the same batch.I have not found this problem when foil electrodes are used with the same dielectric."
Yep. Great writeup. Unfortunately, it doesn't seem to contain any direct comparison of the Wima MKP and FKP. Then again, the excerpt you quoted does indicate that some part-to-part variation is to be expected, in particular with the MKP.
Tom
Tom
Unfortunately, in the larger values (≥150nF), the size and cost of the FKPs makes them impractical----9 x bigger and 4 x more $$$$.
In a world of $2k speakers and $6k interconnects ("wires"), how can we complain about the cost of a coffee-can full of nFd?
FKP4G041507G00KYSD WIMA Film Capacitors 400V 1.5uF 10% $4.21 does not seem outrageous to me. And it is about the size of a cap a tenth that uFd in the 1960s.
But thats the reality of the so called high end nowadays.
Look inside of amp gears and you will find that in every price range the manufacturers are using cheap components. They will claim that the parts have excellent measurements and therefore have to sound excellent. But they are glad to use those cheap parts, its for their benefit. Most often, only the housing of electronic gear is worth a lot, in some cases I would rate the price more expensive than the whole electronics inside.
Thats what you get if you buy high end today.
Look inside of amp gears and you will find that in every price range the manufacturers are using cheap components. They will claim that the parts have excellent measurements and therefore have to sound excellent. But they are glad to use those cheap parts, its for their benefit. Most often, only the housing of electronic gear is worth a lot, in some cases I would rate the price more expensive than the whole electronics inside.
Thats what you get if you buy high end today.
That's true. And in the world of 60's amps (mostly tube) that would be fine. But in today's world of SS electronics, the sheer SIZE of that Wima FKP (41.5 x 20 x 39.5H---37.5 LS mm) would probably be prohibitive on most circuit boards. Especially when you can get a 1.5µF Nichicon BiPolar cap (8dia. x 11.5H 3.5 LS mm) for 63¢.
> in today's world of SS electronics, the sheer SIZE of that ... would probably be prohibitive on most circuit boards. ...Nichicon BiPolar ... 63¢
Last time I built something "CLEAN!!" I *started* with the large input film caps, and let the size be what it wanted to be (even though this had to travel a lot).
But that was for ME. If it was for other people, yeah, an e-cap is fine.
Last time I built something "CLEAN!!" I *started* with the large input film caps, and let the size be what it wanted to be (even though this had to travel a lot).
But that was for ME. If it was for other people, yeah, an e-cap is fine.
A capable circuit designer can get stellar performance from off-the-shelf components, so why use anything else?
To nudge back in the direction of the thread topic: I once compared three 220 nF film caps on an HP 4194A impedance analyzer: A $0.50 Panasonic EF-series, a $2 Solen film cap, and a $20 Mundorf silver-in-oil. The Panasonic measured closer to an ideal cap (lower ESR, higher SRF) than the others. The Mundorf measured the worst.
Tom
I believe you. But the measurements that we have don't always tell the whole story. Old Neve mixing consoles, which are full of transformers and awful-measuring tantalum capacitors, sound absolutely divine. I'm NOT saying that the $20 Mundorf will sound better because it measures worse, either. I just think that we can hear things we can't measure (YET).
I agree with that. Some measurements in isolation are too simplistic. Others, such as the multi-tone IMD measurement I have been promoting for a few years tell more of the story. It takes a suite of measurements to properly characterize a circuit.
I also think it's worthwhile to consider the psychology of cognition and perception in the mix.
That I personally doubt. But the fact that we can measure something does not mean that we are measuring it.
Anyway. I don't mean to derail this thread and turn it into another objectivist vs subjectivist thread. Those usually don't develop well.
All I intended to say is that the more expensive, boutique brand is often not any better than a much lower cost generic part. In some cases they're worse. But they look impressive in the build pictures, so the marketing department loves them. 🙂
Tom